[HN Gopher] Korean nuclear fusion reactor achieves 100MdegC for ...
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Korean nuclear fusion reactor achieves 100MdegC for 30 seconds
Author : yreg
Score : 656 points
Date : 2022-09-07 19:58 UTC (1 days ago)
(HTM) web link (www.shiningscience.com)
(TXT) w3m dump (www.shiningscience.com)
| rkagerer wrote:
| For reference, the core of the Sun is around 15MdegC (cooling to
| ~5500degC at its surface).
|
| Oh, and about 160M times bigger in diameter.
| jacknews wrote:
| I completely support fusion efforts from a science point of view,
| but let's be honest, an economic reactor for electricity
| generation is _still_ decades away, it may not even be feasible,
| and it certainly won 't be as 'clean' as is being sold, using D-T
| fusion.
|
| We should switch a good chunk of fussion funding towards 'clean'
| fission; travelling wave reactors, molten salt, small modular
| reactors, thorium, etc, etc. Some of these have a chance at being
| commercially viable and making a real impact this decade, not
| half a century or more hence.
| bborud wrote:
| You can iterate the argument one step further and say that
| affordable nuclear is too far into the future, and that we
| should instead focus on more immediately realizable options
| such as wind, solar, geothermal etc.
|
| This is where much of the energy debate in Europe is at now. It
| is _exactly_ the same argument being used against fission.
|
| Pick any technology that has come to fruition in the last
| decade. Video streaming as a substitute for cable and
| terrestrial TV. Mass adoption of Smart Phones. EVs becoming a
| viable option for broad populations of car owners. A space
| startup that came from nowhere and rapidly out-competed the
| incumbents. All of them.
|
| Remember the Apollo astronauts who walked on the moon shitting
| on private space companies on C-SPAN not that many years ago?
|
| Look at the time span between people dismissing these
| technologies as off in the distant future and when they
| arrived. People have a tendency to assume that tomorrow will be
| the same as today.
|
| Affordable nuclear is still some years away. I think the events
| in Europe actually shortened that distance into the future by a
| significant amount just in the last 6 months. But fission power
| is still "too slow". Fusion is even more years away into the
| future. If/When it comes to fruition people _are_ going to be
| surprised, and none more so than the experts.
|
| Because the experts are almost _always_ wrong for a good while
| after disruptive breakthroughs have already happened.
|
| It means we have to think ahead and make sufficient bets on
| technologies that exist at all time scales. And the more
| potential they have for delivering stable base load, the higher
| the payoff.
|
| Yes we have to invest in both fission and fusion. And we have
| to invest a lot more than we already do.
| 7952 wrote:
| None of those technologies has ever been cheap exactly. It
| always costs someone a lot of money. But because it is
| desirable it can be justified. Nuclear power is identical to
| any other source of power as far as the consumer is concerned
|
| Also, if we are going to be super optimistic about fission we
| can also be optimistic about battery storage and solar.
| bborud wrote:
| Lots of technologies have gone from "not cheap" to dirt
| cheap in my lifetime so this isn't really an argument.
|
| Let me give you an example. Right now I have at least half
| a dozen 6-9 channel IMUs on my person. Most of which cost
| from a couple of dollars to a few cents apiece. When I was
| a kid a much less precise IMU could cost more than a decent
| car. If you asked people who worked on equipment containing
| IMUs back then they would probably not have predicted
| today's price point and the fact that billions of these
| devices are owned by people of all levels of wealth.
|
| Before the advent of MEMS devices, cheap chip manufacturing
| and a mobile market to drive up volumes and drive down
| costs it was fairly hard to envision that you could make a
| decent precision IMU and make a profit selling it for
| pocket change.
|
| In fact, when I was a kid, nobody very few people who ran
| numbers really believed that mobile phones could be had for
| less money than a dinner at a not-even-fantastic-restaurant
| within our lifetime.
|
| If you are to argue that something can't happen, you kind
| of have to find compelling argument rooted in fundamental
| limitations.
|
| I don't think fission is ever going to be cheap as it deals
| with materials that are tricky. But I'm not ready to make
| the assumption that they can't be made cheaper per kWh
| than, say wind or solar (as you have to combine these with
| storage to solve the same problem).
| jacknews wrote:
| I don't think this is quite the same argument. I agree with
| funding the future.
|
| But in this case the 'experts' seem to be putting all the
| funding toward fusion, which is likely decades away, if at
| all, and almost not at all toward new fission, which could be
| viable this decade.
| ncmncm wrote:
| Except, it cannot.
|
| No new nuke design begun today could produce any power
| before 2035. The money spent building it, spent on
| renewables instead, would produce immediately, displace CO2
| immediately, and produce more.
| bborud wrote:
| You made a categorical statement, yet provided no
| reasonable argument to back it up, so please don't be
| upset if I'm inclined to not enthusiastically adopt your
| position.
|
| I've spent much of my life listening to what people say
| various things can't be done. And then either seeing
| people do what was "impossible" or, in a few cases,
| participating in doing what other people said couldn't be
| done. It is the same kind of mental pitfall that
| magicians exploit: the audience fail to imagine the
| amount of effort that can be brought to bear and hence
| make assumptions about what is possible within a scope
| that wasn't as limited as they thought.
|
| It doesn't happen often, but it happens often enough that
| I'm disinclined to dismiss possibilities before they have
| been properly explored.
|
| I'm not saying fission can be accelerated to, say, a sub
| decade path to realization. I'm saying that categorically
| stating this timetable can't be accelerated is a bit
| premature before anyone has made a serious attempt.
|
| So what do I mean by "serious attempt"?
|
| If you look at investment in fission over the past
| decade, in my book that qualifies as the world not having
| made a serious attempt. The level of investment needs to
| be perhaps on the order of 2-3 magnitudes higher for it
| to be a "serious attempt". And it doesn't have to be a
| null sum game in the sense that it would all have to come
| from reallocating investments from other energy sectors -
| it could be that we allocate more resources to the energy
| sector.
| ncmncm wrote:
| We have many decades' experience with fission projects.
|
| The most reliable prediction, historically, has been that
| they were lying about costs. No fission project has ever
| been gone forward without massive public subsidy. There
| are no projects in progress now or proposed that do not
| rely on massive subsidies. These go back to the first
| "too cheap to meter" claims.
| bborud wrote:
| We have decades more experience with electrical cars. And
| for over 100 years, electrical cars were a curiosity. For
| at least half of the time we've had nuclear power we've
| also had people saying that electrical won't have a
| chance at displacing ICU cars. "Experts" being far more
| adamant than laypeople because they "know" it isn't going
| to happen.
|
| And yet, this appears to be happening.
|
| The thing is, arguing that "X can't happen because X
| hasn't happened before" isn't a proper argument because
| everything around you has spent more time not happening
| than happening.
|
| A compelling argument is one that argues _how_ X can 't
| happen for reasons we can know. For instance if we bang
| up against hard limits imposed by natural law that we
| just can't get around.
| ncmncm wrote:
| There is no record of electrical car promoters
| systematically lying about their costs.
|
| Electric cars were not, in fact, a practical prospect
| until lithium battery technology improved radically. It
| was not the prospect of electric cars that drove the
| improvement. It was cell phones. As soon as the batteries
| got good enough, practical electric cars started to be
| offered, cash on the barrelhead, what you see is what you
| get.
|
| Nuke experience resembles this in exactly zero details.
| It is frankly weird you thought otherwise.
| jacknews wrote:
| Which currently-deployable renewables work at night, when
| there's no wind, and can produce enough for our base load
| needs?
|
| Small modular reactors could well be operating before the
| end of the decade, with government assistance, esp.
| regarding permitting.
|
| But that's beside the point, and your argument is exactly
| that criticized above - ie we should spend today on
| current tech rather than research for tomorrow.
| Renewables are now essentially 'baked', and from the
| government pov it's just a matter of tweaking regulations
| etc to encourage further commercial rollout.
|
| But we should also be researching for the future, and new
| nuclear needs help to actually develop the technology to
| commercial viability, along with say, deep geothermal. In
| comparison fusion is pie-in-the-sky, and doesn't warrant
| it's outsized funding - some funding (for the science),
| yes.
| ncmncm wrote:
| Anything that depends on converting heat will be more
| expensive than renewables + storage. So, nukes, howsoever
| clever, have no place.
|
| Please do not pretend not to have heard of storage. It
| fools no one, but makes you look foolish.
| jacknews wrote:
| lol, go and do some calculations, and come back and tell
| us how many batteries we'll need to cover base load
| during a couple of weeks of calm, dark-skies snow or
| rain.
|
| I agree we should be investing in storage technologies
| too, just not to the exclusion of other options.
| pfdietz wrote:
| People have done the calculations on how much a 100%
| renewable energy economy would cost.
|
| https://ieeexplore.ieee.org/document/9837910
|
| > Even former critics must admit that adding e-fuels
| through PtX makes 100% RE possible at costs similar to
| fossil fuels. These critics are still questioning whether
| 100% RE is the cheapest solution but no longer claim it
| would be unfeasible or prohibitively expensive.
| myrmidon wrote:
| US residences currently use ~1kW per household. This
| means that _current_ car-battery sized storage (~100kwh)
| would already last almost a week.
|
| Note that other western industrialized nations are
| significantly less wasteful with residential electricity;
| the same storage would last the average german household
| already over 2 weeks for example. Part of the difference
| might be explained by air conditioning-- but this
| conveniently requires very little storage anyway.
| bborud wrote:
| > US residences currently use ~1kW per household
|
| That sentence doesn't make a lot of sense to me.
| myrmidon wrote:
| Residential electricity use is around 10000 kWh per
| household per year (10000kWh/year / 365days/year /
| 24hours/day <=> ~1kW).
|
| Meaning that on average, each household requires ~1kW of
| electricity.
| ncmncm wrote:
| Affordable nuclear recedes further with each passing day, as
| costs for better tech continue on down.
|
| Each dollar diverted from renewables build-out to nukes
| brings climate catastrophe incrementally nearer.
| concordDance wrote:
| Or just make more old style fission reactors and deregulate.
| Even an accident every decade would be well worth it if it got
| costs back down to what they were in the 70s (adjusted for
| inflation), in that the money saved could be invested into
| healthcare with far better returns than we're getting on
| nuclear safety.
| DennisP wrote:
| We have dozens of fusion startups, and dozens of fission
| startups working on everything you suggested. The fusion
| startups build test reactors. The fission startups do paper
| reactors and license applications, and in the US at least, if
| it's not a water-cooled solid uranium reactor, they probably
| won't get any further.
|
| Fix the NRC, and we might get somewhere with fission.
| jacknews wrote:
| I agree, but further, government should be helping with this
| early stage research, and putting more of it towards fission,
| not leaving it to startups.
| gerdesj wrote:
| When I was at school in Abingdon, Oxfordshire (UK) around 1988 my
| physics class (A level aged 17) was somewhat enlivened by a visit
| by a bunch of clever chaps from JET at the Culham labs from up
| the road.
|
| This was the first time I heard the "nuclear fusion is 25 years
| away" joke and it was told as such. We were also shown a graph of
| how many orders of magnitude away from ignition (for want of the
| correct word) by date. It had an initial steep decline but then
| turned right quite sharply and had annoying looking tendency to
| avoid the magic value.
|
| Now, once you have ignition, you have to sustain it and extract
| power from it. That's quite tricky too!
| cygx wrote:
| _We were also shown a graph of how many orders of magnitude
| away from ignition (for want of the correct word) by date_
|
| See p.4-5 of [1] for more recent plots. It includes earlier
| runs of both KSTAR (the experiment under discussion) and EAST
| (the Chinese one mentioned in another comment), but not their
| most recent ones.
|
| [1] https://arxiv.org/abs/2105.10954
| zamadatix wrote:
| For those wanting a quick in browser glance:
| https://i.imgur.com/z7MRk5X.png
| TaylorAlexander wrote:
| Ah wonderful, it looks like we're very close to Q=10 and
| not far off from Q=infinity, heh.
| gerdesj wrote:
| That looks like a canonical "how we are doing" for the
| trade. You may find it surprising that us civilians find
| that chart a bit tricky to understand.
|
| The graph I was shown was more of a "lies to children" job
| (a Sir Terry Pratchett term for simplification of a concept
| to enable teaching to happen). It looked more like a
| somewhat lumpy y=a/log(bt) where a and b are not 1.
|
| I'm just a simple IT bod what studied a fair bit of
| engineering and a smattering of science back in the day.
| That graph looks like it forgot to put it's bloody knickers
| on. The one in the paper
| https://arxiv.org/pdf/2105.10954.pdf is a bit closer to
| what I remember.
|
| I do feel that we can relax the 25 year rule a bit these
| days. I think we can quite confidently allow 20 years and
| I'm quite cautiously going to suggest 15 instead.
| kortex wrote:
| SimCity says humanity unlocks fusion power plants by
| 2050, and I always thought that was as reasonable an
| estimate as any. Based on page 5, it looks like we should
| have reliable fusion in the lab by 2040, and give that
| 5-10 years to scale up to production plants widely
| available. Hopefully Will Wright turns out to be
| pessimistic and we break through before then!
| Hallucinaut wrote:
| It may seem a bizarre tangent... but humour me: you don't know
| any of the members of Radiohead do you? Right town, time and
| age.
| protoman3000 wrote:
| Correct me if I'm wrong, but wouldn't a huge amount of released
| energy in this scale eventually heat up the planet?
|
| I mean, doesn't the atmosphere in our big greenhouse always
| retains a non-zero amount of energy, no matter the CO2 etc. in
| the air? If that is true, then so far the net energy out flux was
| positive, but now we see with rising greenhouse concentrations
| that it's turning. If we then raise the stock of energy inside
| the greenhouse, it overheats, no?
| mabbo wrote:
| Not even close to the heat generated by the sun's light hitting
| the earth. Orders of magnitude different.
|
| We currently generate most of this power in exactly the same
| way, but by burning coal and gas to make heat rather than by
| nuclear fusion.
|
| The difference would be that no CO2 is released with a fusion
| power plant.
| Schroedingersat wrote:
| Current primary energy is ~35TW. Total insolation is around
| 150PW
|
| 5W/m^2 or 0.5% is enough forcing to be catastrophic which
| puts us roughly in the 20x current consumption or 2100-2140
| range if we don't stop growth.
|
| So yes. We're in exactly the same position now WRT heat as we
| were when scientists first started warning about greenhouse
| gases. Ironically switching to PVs and starting the
| transition was an option then too even though the first
| commercial PVs were thought to be thermoelectric.
|
| We can all live well, but we can't all live in an air
| conditioned uninsulated mcmansion with a 9 tonne electric suv
| each going everywhere via highway and throwing out half our
| appliances which we move by truck every year.
| ncmncm wrote:
| No, it wouldn't. The sun dumps untold petawatts of heat on us
| 24/7. We will never produce anything as much as the difference
| from one week to the next.
|
| In any case this stuff will never produce so much as one
| solitary kWh of commercial power, so the question is wholly
| academic. Fusion heat would cost much, much more to extract in
| usable form than fission, and fission is already not
| competitive.
|
| The dream of unlimited power without spending on fuel -- capex
| but no opex -- is already here, and we call it renewables +
| storage. We just need to build it out fast enough that
| civilization doesn't collapse first. Fusion is a pernicious
| distraction, in present circumstance.
| concordDance wrote:
| > The dream of unlimited power without spending on fuel --
| capex but no opex -- is already here, and we call it
| renewables + storage.
|
| This is inaccurate, both production and storage have service
| lives (in years, cycles or both) so need to be continually
| replaced. This is opex in practice
| ncmncm wrote:
| Yet, already less than opex for steam turbines. And still
| falling.
| stjohnswarts wrote:
| I think you are confusing heat with energy.
| bluepnume wrote:
| Sure, but we can divert some of that energy to power wind
| turbines, which ought to cool things down a bit.
| Schroedingersat wrote:
| You are completely correct if we attempt to continue
| exponential growth. The limit is under a century away at
| historical energy growth rates.
|
| 10 billion or so people can live at current average western
| levels without it being a problem.
| elihu wrote:
| > "This team is finding that the density confinement is actually
| a bit lower than traditional operating modes, which is not
| necessarily a bad thing, because it's compensated for by higher
| temperatures in the core," he says. "It's definitely exciting,
| but there's a big uncertainty about how well our understanding of
| the physics scales to larger devices. So something like ITER is
| going to be much bigger than KSTAR".
|
| This made me wonder when ITER was going to actually be up and
| running. From wikipedia:
|
| > "The reactor was expected to take 10 years to build and ITER
| had planned to test its first plasma in 2020 and achieve full
| fusion by 2023, however the schedule is now to test first plasma
| in 2025 and full fusion in 2035."
|
| So, it sounds like it'll start doing something within a few
| years, but it'll probably be a long time before it produces
| significant scientific results.
|
| By the time ITER is running, maybe some other group will beat
| them to it (like the MIT ARC or SPARC reactors, which use more
| recent, better superconductors and don't need to be anywhere near
| as big).
|
| https://en.wikipedia.org/wiki/ITER
| ncmncm wrote:
| ITER if ever finished will have _exactly zero_ apparatus to
| extract useful power.
|
| They are not even talking about _starting_ on a power plant
| before 2050, or finishing before 2070.
|
| It will of course all be dropped long before then, one way or
| another. Either we build out renewables fast enough, or
| civilization collapses before we get there. Either way, no
| fusion power.
| elihu wrote:
| Extracting useful power isn't really the point of ITER; the
| main thing is to operate the machine long enough to produce
| useful data that everyone else can use to build reactors that
| aren't based on technology that's several decades out of
| date.
|
| I don't think ITER would be dropped because of renewables.
| Even if we had enough energy to power our civilization,
| there's always other things we could do if we had more.
| Civilization collapse could put a halt to ITER, but another
| possibility is the project could be dropped because someone
| else beats them to it and they don't need to finish this
| expensive machine just to find out what everyone already
| knows about magnetic plasma confinement.
| dmix wrote:
| Was there not a cheaper/faster way to do the ITER R&D?
|
| I guess there's also lot of value in getting the private
| industry expertise in building the magnents and all of the
| complicated sub-parts. Basically training a whole
| generation in practical advanced fusion development.
| Hopefully there will be some real-world application in time
| for this knowledge and expertise to be transferable.
| ncmncm wrote:
| Dropped is dropped is dropped.
|
| Continuing to spend up until then diverts money from other
| things not best dropped.
|
| Confining plasma does not suffice to get you power
| generation.
| yreg wrote:
| Seems (like other contributors) Russia is manufacturing parts
| for it. Hope the current events won't delay the project.
| Filligree wrote:
| One of the main reasons it's so delayed, is that _everyone_
| gets to make some of the parts. Which then have to be put
| together on-site, despite inevitable mismatches.
|
| Reducing the number of countries involved will probably just
| speed it up.
| ncmncm wrote:
| Not noticeably.
|
| The longer it takes, the longer the money flows. The moment
| its real prospects become clear to everybody, the money
| stops.
| scifibestfi wrote:
| Let's say they manage to scale this up. What effect would it have
| on humanity? Climate change is solved. What else?
| thehappypm wrote:
| Idk. If you want a steady stream of energy enough to power a
| small house, you can achieve that for $20k today with a big
| enough solar panel and a PowerWall. Fusion has to be cheap as
| well as effective.
| [deleted]
| ncmncm wrote:
| Each dollar diverted to this from building out renewables
| brings climate disaster, global civilization collapse, and
| billions starving, incrementally nearer.
| throwaway742 wrote:
| There is no reason we can't do both.
| ncmncm wrote:
| Dollars are fungible. A dollar spent on X is manifestly not
| spent on Y, except by accident.
| sien wrote:
| With the knowledge that comes out of building fusion power
| plants the next thing to build is fusion rockets.
|
| https://en.wikipedia.org/wiki/Project_Daedalus
| yreg wrote:
| Not to be confused with USS Daedalus
|
| https://stargate.fandom.com/wiki/Daedalus
| MichaelCollins wrote:
| Little effect I think. Fusion power can do little that fission
| power can't do already, which is provide "free" power after you
| look past the cost to build and maintain the plant. The best
| advantage of fusion power is the public perception is presently
| better.
| Thetawaves wrote:
| Don't ignore the fact that uranium reserves would not last
| 100 years if we used it as our sole power source.
| yreg wrote:
| That seems like an estimate on the lower side, but still,
| in those 100 years we should be able to at least move to
| thorium, no? Which could last a lot longer.
| flaviut wrote:
| You should say "current" uranium reserves.
|
| As demand goes up, so does supply, as additional reserves
| are prospected for and more costly uranium sources become
| economically viable.
|
| There's not much reason to prove reserves if you won't be
| able to profitably mine them.
| akvadrako wrote:
| There is enough uranium on Earth for getting all our
| current power for millions of years. (source: wikipedia)
|
| There just isn't much at current prices, but fuel costs are
| not significant so prices cam rise.
| Thetawaves wrote:
| Linky? It seems preposterous to assume that we will be
| able to map the energy budget of earthlings over a
| thousand millennia.
| DennisP wrote:
| If you're comparing with solar, it seems fair to assume a
| level of energy usage that could reasonably be supplied
| by solar. We're not going to cover the planet in solar
| panels.
|
| With that assumption, fission can last for a very long
| time if we get uranium from the oceans, and burn it in
| fast reactors. The oceans hold four billion tons of
| uranium, and with fast reactors we'd use it a hundred
| times more efficiently than we do today.
| ithkuil wrote:
| Is the safety profile any better? Or is it just public
| perception?
| cygx wrote:
| There are major differences. For one, in case of
| catastrophic failure, the plasma will dissipate, its
| temperature will drop and the fusion reaction will stop.
| ncmncm wrote:
| In case of catastrophic failure, thousands of tons of
| radioactivated lithium hydroxide burn uncontrollably, the
| smoke producing drain opener in contact with mucus
| membranes and lungs.
| ncmncm wrote:
| (Lithium hydride. The resulting caustic vapor is lithium
| hydroxide.)
| AnimalMuppet wrote:
| This. The hard part is keeping it going, not getting it
| to stop.
|
| Also, if I understand correctly, the waste products are a
| lot less nasty.
| wizofaus wrote:
| > The hard part is keeping it going, not getting it to
| stop.
|
| I'm rather glad that doesn't apply to the fusion reactor
| in the sky that we'll be fully dependent on for a while
| yet.
| MichaelCollins wrote:
| It's a lot easier to build passively safe fission power
| plants than _any_ sort of fusion power plant.
|
| https://en.wikipedia.org/wiki/Passive_nuclear_safety
| u320 wrote:
| The safety profile is better with fusion, but I think you
| underestimate how good the safety profile of nuclear is
| these days. We haven't had any significant incidents since
| Fukushima, but we upgraded the safety mechanisms of our
| nuclear plants a lot based on that experience. Nuclear is
| on a path similar to flight, were we started off with very
| risky airline travel and got to a point where you are more
| likely to suffer an accident on the taxi on your way to the
| airport.
| coffeeblack wrote:
| Fission power is already the second safest form of energy
| production, after hydro.
| 93po wrote:
| At least one source saying hydro causes more deaths than
| fission:
|
| https://www.businessinsider.com/dam-safety-statistics-
| risk-o...
| DennisP wrote:
| And the worst power plant accident ever was Banqaio Dam,
| which killed 26,000 people immediately, and another
| 150,000 or so in the aftermath.
| ok_dad wrote:
| The lack of major radioactive waste is a plus, only the
| pipes and stuff inside the core of the reactor will have
| radioactive elements due to neutron activation. The only
| waste from it otherwise is helium (and tritium, which is
| re-used in the reaction later).
| rosywoozlechan wrote:
| isn't helium valuable? seems like a good "waste" to
| produce
| pfdietz wrote:
| Very little will be produced. Indeed, a fusion reactor
| may leak more He from its cryo system than it creates.
| OJFord wrote:
| Yeah that's GP's point by the 'only'. It's 'waste' as in
| a byproduct.
|
| It's part of the reason fusion's so sought after - it
| doesn't result in anything bad or that has to be
| carefully sequestered.
|
| (Apart from extraordinary heat I suppose. Perhaps there's
| an argument the actual reactor would always be a pretty
| risky place. But any incident isolated at least, worst
| case a remote industrial building burns down beyond
| economical repair.)
| DennisP wrote:
| The temperature is high but the amount of heat is no
| different than other thermal power plants. The atoms move
| very fast, but there aren't many of them.
| Apocryphon wrote:
| Safe airships for all!
| throwaway0a5e wrote:
| Doesn't matter.
|
| Public perception > reality.
|
| Look at hydroelectric. Terrible for ecosystems, decent
| number of deadly failures over the years, way better
| perception and less pushback from the public than fission.
| ncmncm wrote:
| Dams are being taken down at an increasing rate as it is
| recognized that the fisheries they destroyed are far more
| valuable than anything they produce.
| Blikkentrekker wrote:
| Even with fusion, it's very clear that many politicians are
| afraid of it simply because of the word "nuclear" in it.
|
| As nuclear fission, nuclear fusion might simply not be used
| because of that scary word alone.
| DennisP wrote:
| It's possible that some Western countries will be that
| silly at first, but China certainly won't. Everybody else
| will come to their senses before long.
| z3rgl1ng wrote:
| Jevon's paradox implies we'd have a brief respite,
| chronologically speaking, before having to tackle something
| like heat shedding.
| myrmidon wrote:
| None.
|
| We already have _proven_ basically unlimited electric energy in
| the form of PV panels (and batteries if you need it stored). So
| far, that tech has not solved climate change at all, because
| actually building enough of these things is something that
| people need to be willing to pay for.
| hinkley wrote:
| Climate change not solved. This is another in our long series
| of silver bullets.
|
| Greenhouse gases retain heat. Sea level temperature is a
| function of ambient heat due to sunlight and other heat
| sources, minus the rate at which it dissipates into outer
| space, mediated by the insulation effect of the atmosphere.
|
| Projects that try to reduce the carbon intensity of energy are
| focused on changing the denominator in the equation. The
| current aim of these projects is to produce a cheap and
| plentiful energy source, via a heat engine. What they are
| actually chasing, whether they admit it to themselves or not,
| is a cheap and plentiful heat source. If they succeed they
| change both the numerator and the denominator, which ends up
| partially cancelling each other.
|
| Wind and solar are different because they tap into an existing
| heat engine, instead of trying to build a new one.
|
| What we as a people need is a fusion plant that costs less per
| KWH than a fossil fuel power plant with tariffs to account for
| the cost of the carbon dioxide, but still about as expensive as
| a fossil fuel plant where the carbon is free. If we actually
| got a fusion plant that was 10x more cost efficient then we'll
| just introduce the concept of heat pollution to the
| conversation, swapping out the villain in the story but keeping
| the same outcome.
| u320 wrote:
| Heat pollution from power generation is a non-problem. We
| will run out of raw materials to build power plants out of
| long before this happens. This is what happens when people
| don't run the numbers.
| robertlagrant wrote:
| Adding some invented constraints on to the problem of nuclear
| fusion is the most bikesheddy thing I've ever read.
| hinkley wrote:
| What invented constraints? We've been chasing nuclear
| fusion since long before we really cared about greenhouse
| gas emissions. We want 'cheap and plentiful power'.
| Greenhouse gas intensity is a recent addition to the set of
| goals. It doesn't replace the existing motives, and to
| claim otherwise is greenwashing.
| robertlagrant wrote:
| This one:
|
| > What we as a people need is a fusion plant that costs
| less per KWH than a fossil fuel power plant with tariffs
| to account for the cost of the carbon dioxide, but still
| about as expensive as a fossil fuel plant where the
| carbon is free
|
| That the fusion plant can't be too expensive, or too
| cheap.
| [deleted]
| 93po wrote:
| Are you saying the heat output of a fusion generator would be
| so great that it would impact climate change?
| hinkley wrote:
| If you give people a generator that produces "cheap and
| plentiful energy"? Absolutely. Total world power
| dissipation increases as fast as they can build the plants.
| If we never produce another molecule of CO2 again we might
| be okay in that situation, but things like that don't
| change overnight.
|
| edit: conclusion
|
| edit again: I'm extrapolating from
| https://en.wikipedia.org/wiki/Jevons_paradox but didn't
| remember what it was called
| ajnin wrote:
| Rough order of magnitude calculation, the Earth receives
| about 1000W/m^2, that's 6370km^2 * pi * 1000W/M2 ~ 1e17W,
| and according to Wikipedia the global energy use of
| humanity is 7050 millions tons of oil equivalent per year
| so 7050 * 11.63TWh / 1year ~ 1e13W. So we have about 4
| orders of magnitude of difference here. Does the human
| heat output make any difference? Probably not.
| Thetawaves wrote:
| Hardly. The amount of energy trapped by the atmosphere is
| vastly greater than the heat capacity we would wish to be
| able to produce, and the corollary - the amount of energy
| irradiated by the earth into space is vastly greater than
| amount of heat we wish to produce.
| hinkley wrote:
| And it was balanced, so it doesn't matter if it's fifty
| terrawatts or fifty million. What matters is:
|
| > The growth in Earth's energy imbalance from satellite
| and in situ measurements (2005-2019). A rate of +1.0 W/m2
| summed over the planet's surface equates to a continuous
| heat uptake of about 500 terawatts (~0.3% of the incident
| solar radiation).[2][35]
|
| https://en.wikipedia.org/wiki/Earth's_energy_budget
|
| I found a chart that says we're producing about 25,000
| TWh per year of power now, or 2.9 TW continuous to put it
| in the same units. But what is the efficiency of those
| plants? 35%? That's 8.3 TW of heat, which is already 1.6%
| of our budget surplus. If we dogleg our energy production
| while thinking it virtue signaling, that quickly becomes
| 5% of a number that is slowly cooking us. That brings
| doomsday in by years.
|
| We can't endlessly dump heat into the atmosphere any more
| than we can continuously dump mercury into the oceans.
| [deleted]
| mlazos wrote:
| In your equation above. The sun produces so much more
| ambient heat I imagine everything else is a rounding
| error. I highly doubt any number of fusion plants would
| affect global temperature.
| hinkley wrote:
| Please check my math here
| https://news.ycombinator.com/item?id=32760914
|
| I'm getting 1.6% of our heat surplus at present power
| production rates, and I'm saying what if we triple our
| power production because it's cheap and clean now?
|
| Wind doesn't increase this number. Nor does hydro. Solar
| only does if the albedo is lower than ambient. Tidal... I
| wouldn't even know where to start calculating that. Heat
| engines increase it by something like 300% of the power
| that gets to your light switch.
| ncmncm wrote:
| Still negligible.
|
| Fusion and fission are bad ideas on their own merits,
| regardless of heat they might produce.
| coffeeblack wrote:
| Question is, how much will the kWh cost, all costs considered.
| And how much time does it take to build.
| quonn wrote:
| Long term, yes. But much of the climate change problem is
| decided in the next 25 years. Even if this reactor would work
| right now, building enough of them in that time frame
| everywhere, switching all industry and factories to electric,
| switching all transportation and cars and heating systems in
| all the houses to electric is very tough.
|
| So it's still very challenging.
| notfish wrote:
| Exactly. I'd also add that climate change is a just a symptom
| of us reaching the natural carrying capacity of Earth for
| humans, so adding new ways of generating power doesn't
| completely eliminate the issue.
| vanviegen wrote:
| Very true. Though an abundance of cheap energy may prove
| helpful in brute force engineering some other problems out
| of existence. I'm thinking of recycling and geo-engineering
| in particular.
| ncmncm wrote:
| Fusion cannot produce cheap energy, in any case.
|
| Fuel cost is a substantial fraction of exactly _none_ of
| the generation methods in use.
| u320 wrote:
| Can you explain what you mean by "the natural carrying
| capacity of Earth for humans". You framed this like it's
| something that exists outside of technology.
| elf25 wrote:
| Schroedingersat wrote:
| Peak everything is happening over the next little while.
|
| Direct thermal climate foring is a couple of orders of
| magnitude out from current energy use.
|
| Classical computing is almost finished.
|
| Many minerals are at the point where extraction takes a
| rapidly increasing amount of energy per tonne.
|
| Land used for grazing and agriculture is over half of
| habitable land.
|
| Fishing is wiping out entire ecosystems.
|
| It's time to think about moving earth to a steady state
| economy.
| Schroedingersat wrote:
| > What effect would it have on humanity? Climate change is
| solved.
|
| Not really. It'll just be another tool for the fossil fuel
| lobby to use to misdirect attention from what will make them
| irrelevant forever (reduction and sunlight).
|
| Even if the reactor part is free and 100% reliable. Getting
| heat out of a 100 million degree chamber that is spewing
| neutrons everywhere and turning it into electricity is much
| much harder and more expensive than collecting some photons and
| building a train.
| yreg wrote:
| As the fossil fuel industry becomes obsolete, it would be
| wise to rebrand themselves into carbon removal and lobby for
| high payouts of carbon credits.
|
| https://www.economist.com/the-world-if/2020/07/04/what-if-
| ca... (not sure how to overcome the paywall)
| DennisP wrote:
| Archive gets around their paywall: https://archive.ph/Q9b6b
|
| Pretty interesting article.
| alas44 wrote:
| Climate change has inertia so probably not solved by the time
| we have industrial scale fusion + would not solve the two other
| main anthropic activity related problems: biodiversity loss and
| depletion of natural resources
| wizofaus wrote:
| Would depletion of natural resources be so much of an issue
| if we could use fusion to recreate them? (after all, they
| didn't come into existence by magic...) Biodiversity is a
| bigger problem given the sheer levels of complexity and our
| relatively poor understanding of exactly how we depend on the
| exact make-up of the biosphere. Most likely humanity could
| survive without it, but it would be a poor sort of existence
| - our bodies and brains evolved in tandem with the huge
| diversity of life around us and is optimised to thrive in
| that context.
| therealdrag0 wrote:
| This is why my primary donations are to bio diversity and
| endangered animal protection orgs instead of climate
| change.
| digianarchist wrote:
| Not all natural resources are renewable. Unlimited cheap
| energy would probably be more harmful to nature in the
| short term. Unrestricted mining, logging and human
| expansion.
| blibble wrote:
| with unlimited cheap energy you can pull CO2 out of the
| atmosphere, produce hydrocarbons and pump them back into the
| wells
| macksd wrote:
| I don't know what the math looks like here, but there is
| waste heat in this, right? We could lower CO2, but
| "unlimited cheap energy" at the scale required to make a
| dent in climate change surely gives off a pretty phenomenal
| amount of heat. I wonder what the equation looks like for
| the overall effect on the planet.
| blibble wrote:
| my understanding of chemistry is poor, but presumably if
| energy is liberated from combustion, reversing that
| reaction requires energy
|
| (with some input to kick it off possibly)
|
| regardless, the earth receives 173,000 TW of solar
| radiation from the sun
|
| we have a way to go yet
| ben_w wrote:
| One could, but this is unlikely to actually be done unless
| there is an economic incentive, which is basically why
| everyone put the CO2 into the air in the first place
| despite knowing the consequences.
| blibble wrote:
| carbon credits and carbon trading were invented, what,
| twenty years ago?
| ben_w wrote:
| Indeed, and look how effective they've been.
| blibble wrote:
| extremely effective indeed?
|
| (where implemented)
|
| with unlimited clean energy you'd be able to print carbon
| credits as a result of direct hydrocarbon sequestration
|
| the economic infrastructure already exists today, but the
| cost structure doesn't work
| Bakary wrote:
| Isn't the fact that they were not implemented part of the
| definition of their failure? Since it's supposed to be
| the backbone of the solution that allows the neoliberal
| model to continue without significant changes, the fact
| that it was not adopted is a clear indictment.
| blibble wrote:
| no?
|
| my town's anti-dog fouling laws aren't a failure because
| there exist other towns that permit dog fouling
|
| in terms of contribution to global emissions everything
| is dominated by Chinese growth
|
| but that doesn't mean that it hasn't curtailed emissions
| significantly where implemented
| Bakary wrote:
| That's not the point.
|
| The fundamental appeal of these carbon schemes is that
| they can permit a theoretical decrease in greenhouse
| gases while keeping the current economic model alive and
| well. But despite being greatly amenable to the way
| things currently are, with few extra efforts or changes
| needed in comparison to other types of plans for the
| climate, they were not widely adopted at all.
|
| The system these schemes were designed to save was unable
| to pick even the lowest-hanging fruit that could have
| potentially saved it.
|
| So yes, it might work with unlimited clean energy, but if
| we have that we are already in a different arena
| altogether with entirely new problems and solutions and
| where carbon credits are unnecessary anyway.
|
| The fact that the cost-structure doesn't work now _is_
| the indictment. Cost structures is how we got into all
| this mess to begin with. Saying carbon credits work is
| like saying a healthy lifestyle can prevent obesity. It
| 's of course true on its own, but also fairly useless
| since the problem is that people are very resistant to
| adopting such a lifestyle.
| blibble wrote:
| > The fact that the cost-structure doesn't work now is
| the indictment.
|
| given this entire thread is about a hypothetical future
| where we have unlimited clean energy I'm not sure why
| this is a problem
| Bakary wrote:
| The subthread was whether the carbon schemes are
| effective. They are either ineffective because they do
| not fix the incentive problem, or effective in a context
| where they are no longer needed
| blibble wrote:
| it's my subthread, and it's explicitly about what I said.
| anon291 wrote:
| better yet... you can kep current hydrocarbon economy
| factories, vehicles, etc in operation by simply producing
| fuels from air. Wil be cheap enough. Hydrocarbons are a
| great, usable source of dense energy.
| X6S1x6Okd1st wrote:
| I really don't think all we need is cheap energy, it's
| still an economically unproductive thing to do, so you need
| a govt to tax people and use the $ to perform
| sequestration.
|
| You need to build out the sequestration plants, maintain
| and run them, only one of those inputs is cheap energy. You
| need to move the carbon to a safe storage facility etc.
|
| It's still a huge undertaking, but would be way simpler if
| we had cheap electricity (which it seems like we will get
| via solar anyways, carbon sequestration could probably be
| turned on and off as needed for grid conditions)
| colinmhayes wrote:
| Carbon tax + cheap energy = people starting carbon
| sequestration companies to sell credits to polluters. As
| long as the tax is high enough we can reach close to zero
| net emissions.
| blibble wrote:
| > You need to move the carbon to a safe storage facility
| etc.
|
| fortunately we already have millions of holes we drilled
| in the ground to get the stuff we burnt originally
| gitanovic wrote:
| Why, do we have unlimited cheap energy? Or the technology
| to pull out CO2 from the atmosphere at this scale yet?
|
| IMO this is wishful thinking, and the wrong attitude to
| solve a problem that is right here right now.
|
| We should focus on reducing emissions, not on hoping that a
| technology that is not yet proven will be available soon
|
| EDIT: sorry for the tone, I just re-read what I wrote.
| Anyhow what I wrote still stands: we have no proof that
| fusion will ever bring unlimited cheap energy, if ever
| viable.
|
| It poses many problems, from neutron activation of the
| blanket to energy extraction, problems that we don't know
| yet how to solve, to solve them in a economically viable
| AND with neutral carbon footprint... well seems just
| unfeasible to me (hope to be proven wrong). Therefore I
| might suggest to pursue more understood ways to mitigate
| the huge problem we have
| ahmedk92 wrote:
| My layman understanding tells me depletion of natural
| resources will be worse if we manage to find a sustainable
| source of energy.
| kibwen wrote:
| It might solve the greenhouse side of climate change, but you
| can't run away from thermodynamics. All electricity generated
| eventually turns into heat. Earth can only radiate so much heat
| into space in a given time period. If you generate more heat
| than Earth is capable of radiating, the planet warms. Don't
| start thinking that "free energy" from fusion reactors means
| that we can generate infinite power (as nice as that would be).
| It just means that the new negative externality would be heat
| itself.
| ncmncm wrote:
| The numbers say otherwise.
|
| If we generated enough spare power to run lots of carbon
| capture equipment, and removed enough carbon, the planet
| would cool.
|
| There are fantastic reasons to abandon fusion, and even
| better reasons to accelerate build-out of renewables, but
| that is not one of them.
| mihaifm wrote:
| Cheap energy means lower costs of manufacturing therefore lower
| prices for consumer goods, thus increasing quality of life.
| u320 wrote:
| There is no reason a priori to assume fusion power will be
| cheap. On the contrary, everything we know about it now
| suggests the opposite.
| haliskerbas wrote:
| At least in North America, things tend to maximize corporate
| profits rather than maximize quality of life.
| robertlagrant wrote:
| They are aligned, at least for those things where consumers
| are the purchaser.
| colinmhayes wrote:
| Profits tend toward 0 in competitive markets.
| hackerlight wrote:
| Everyday goods becoming cheaper have significantly
| increased the quality of life of Americans. That trend will
| continue as energy becomes more abundant. Corporations
| can't monopolize profits on goods that are perfectly
| competitive.
|
| What has decreased the quality of life, which offsets the
| above slightly and makes it appear as thought things aren't
| improving much, is goods that require domestic labor, such
| as education, whose price has outstripped CPI, and goods
| that have artificial regulatory capture which cause their
| price to be artificially high, such as insulin, and demerit
| goods such as opioids which detract from the utility of the
| customer.
| mmahemoff wrote:
| Terraforming, space exploration. On the compute side, running
| extremely fine grained simulations.
| moomoo11 wrote:
| 100M Celsius? Does this contribute to the planetary heating?
| Sorry if dumb question but that is so hot.
|
| How is the heat controlled? Is there any resource that explains
| this thermal part?
| bheadmaster wrote:
| Planetary heating depends on the amount of energy released.
| 100M Celsius refers to the _temperature_ , not _energy_. On a
| small enough space, you could achieve 100M with very little
| energy.
| Aicy wrote:
| Planetary heating is caused by trapping more of the suns energy
| than in the past.
|
| The sun is immensely powerful, and any heat generating activity
| done by humans is negligible compared to the sun. Except for
| activities which increase the suns effects, such as creating
| greenhouse gasses.
| [deleted]
| lake_vincent wrote:
| "While the duration and temperature alone aren't records, the
| simultaneous achievement of heat and stability brings us a step
| closer to a viable fusion reactor - as long as the technique used
| can be scaled up."
|
| Half of the engineers on HN right now:
|
| [...as long as the technique used can be scaled
| up...](PTSD_Chihuahua.jpg)
| keepquestioning wrote:
| Compare this to other tech news today.. a marginal iPhone
| upgrade. Our priorities are wrong.
| ncmncm wrote:
| Yet, the iphone is the more significant event.
| BryLuc wrote:
| rr888 wrote:
| There was a positive fusion article in the WP a few weeks back.
| https://www.washingtonpost.com/technology/2022/08/26/nuclear....
| Looks like things are finally happening.
| ncmncm wrote:
| junon wrote:
| You keep parroting this in this thread without much substance
| behind anything you say. Care to elaborate?
| ncmncm wrote:
| Every scenario for fusion power requires extremely
| expensive processes to extract heat, _and then_ using it to
| drive steam turbines. But operating steam turbines, all by
| itself, costs more than renewables.
|
| These extremely expensive processes would cost way more
| than is needed for fission. But fission is already not
| competitive. (See above.) So there is no future for fusion
| driving heat engines.
|
| There just might possibly be a future in aneutronic fusion,
| fusing deuterium with 3He and extracting the energy
| directly electromagnetically. But all these announcements
| are not about that.
| caseyavila wrote:
| I don't know everything about nuclear fusion so I have to ask: Is
| it actually renewable?
|
| In other words, are the byproducts able to form back into the
| "fuel" at a reasonable rate with the energy input of the Sun? I
| know that a selling point of fusion is that there is such an
| abundance of fuel that this doesn't matter. But if we treat
| finite energy sources as infinite, exponential growth in our
| energy budget means that we will undoubtedly run out of energy,
| as is being done with forests and such.
|
| After all, I have a feeling people at the dawn of the industrial
| revolution thought the amount of coal available in the world
| would serve their needs "practically forever," until energy
| consumption scaled up by thousands of times.
| BjoernKW wrote:
| Ultimately, no method of energy generation is truly renewable,
| including solar. The Sun will run out of fuel in five billion
| years, after all, give or take.
|
| However, for all practical intents and purposes, solar energy
| is renewable. The same holds true for nuclear fusion for at
| least a couple of hundred years, even considering growing
| energy consumption.
| ncmncm wrote:
| People talking about fusion expect to "breed" tritium in their
| reactor. This takes the form of blasting GW of hot neutrons
| into a thousand (or ten-) tons of lithium hydroxide, and
| somehow extracting grams of tritium from it at parts-per-
| billion concentration.
|
| There is no choice about that: it is the only way to get enough
| tritium to keep operating.
| pfdietz wrote:
| I don't know of any blanket design that uses lithium
| hydroxide.
| ncmncm wrote:
| Oops, _lithium hydride_. (Autocorrect strikes again!)
|
| Lithium hydroxide is what you get, as thousands of tons of
| caustic vapor, when it catches fire.
|
| What that does when you breathe it does not bear
| contemplation.
| pfdietz wrote:
| I don't know any that uses lithium hydride, either.
|
| The usual designs are things like Li, PbLi, and lithium
| containing ceramics.
| ncmncm wrote:
| Lithium hydride is like a ceramic, i.e. a high-melting-
| point solid.
|
| But whatever you use, you have to get extremely low
| concentration tritium out, somehow, to run the reactor on
| tomorrow.
| hoseja wrote:
| By the point we've fused significant portion of Earths
| hydrogen, it will really not be a problem to hop over to
| Jupiter for some more. The scales are insane. Energy input of
| the Sun ALSO isn't renewable if you think like this.
| marcyb5st wrote:
| So, the fusion we are talking about here is deuterium - tritium
| fusion as it should be the easiest to achieve. Deuterium is not
| a problem. A rough estimate says that there's enough of the
| stuff to cover 100% of the world needs for thousands of years.
| And it's easy to breed: surround the reactor with water so the
| hydrogen there can capture the stray neutrons.
|
| Tritium, on the other hand, is a problem. It is radioactive
| with a half life of ~12 years and so the little we have needs
| to be produced since we can't really accumulate it. Currently
| it is produced by conventional nuclear reactors. Additionally,
| breeding tritium is harder than deuterium and requires a
| blanket around the reactor that uses other materials to
| multiply the number of stray neutrons. For each atom of Tritium
| that is fused we could get somewhere between 1.1 to 1.7 with a
| theoretical maximum of 2 Tritium atoms so, finally answering
| your question, it is renewable. It's just hard, but a piece of
| cake compared to actually maintaining a stable fusion.
| pfdietz wrote:
| > Deuterium is not a problem. A rough estimate says that
| there's enough of the stuff to cover 100% of the world needs
| for thousands of years.
|
| Far more than that is available.
| ncmncm wrote:
| Right: intractable, but much smaller than other problems.
| marcyb5st wrote:
| I don't see it as intractable. We already have two ways to
| do that at scale. One is proven (the fission reactors), the
| other one is proven but not in an actual fusion reactor
| yet. Iter will have such a blanket for tritium breeding.
|
| Intractable in my mind sounds more like something that you
| don't know how to even start.
| ncmncm wrote:
| How will you extract the tritium at PPB concentration
| from thousands of tons of flame-hot radioactive lithium
| hydroxide? Daily?
|
| Intractable means that anything you try is worse than not
| starting.
| ncmncm wrote:
| Oops, lithium hydride.
|
| (Damn autocorrect.)
| DennisP wrote:
| This article by a Berkeley physicist does the math on fusion
| fuel: https://dothemath.ucsd.edu/2012/01/nuclear-fusion/
|
| Deuterium fuel is the most abundant. There's enough in your
| morning shower to supply all your energy needs for a year.
| There's enough in the oceans to last for _billions_ of years.
| Fusion is as close to renewable as anything, because it 'll
| last until the sun goes out.
|
| Right now most projects are also using tritium fuel, which has
| to be made from lithium. That's plenty abundant but not to the
| extreme of deuterium. But pure deuterium fusion is possible,
| just a little harder. And one prominent fusion startup, Helion,
| is actually using deuterium (along with helium-3, which is the
| waste product of deuterium fusion).
| rjzzleep wrote:
| It's interesting to see that South Korea has such strong nuclear
| research facilities. Taiwan lost a lot of nuclear researchers in
| the past decades. Some of it due to US lobby work and some of it
| due to stupid governmental policies in the recent past. Japan
| which is also quite strong in nuclear seems to be trying to sell
| part of their nuclear industry, a move which turned out
| disastrously for the french.
| cyclingfarther wrote:
| What do South Korea, Taiwan and Japan have in common? Hint: it
| starts with C.
|
| Which is why all three have/had such strong nuclear expertise.
|
| https://en.m.wikipedia.org/wiki/Nuclear_latency
| jimhi wrote:
| Can you spell that out?
|
| They are near / wary of China? That is why they have nuclear
| expertise?
| butterfly771 wrote:
| So is China
| ncmncm wrote:
| If they can unload those turkeys, good for them, bad for
| whoever gets taken in. If they can't, they are no worse off
| than today.
| yongjik wrote:
| South Korea also wasted recent years trying to shut down
| nuclear reactors and painting the nuclear industry as evil
| anti-environmental cabals. It's infuriating that Korea's
| politics is governed by either conservatives (who think
| environmental regulations should bend over for industries) or
| liberals (who think it's "eco-friendly" to shut down nuclear,
| when 44% of the electricity is coming from freaking coal).
| summerlight wrote:
| This issue is not that simple to be framed as "painting the
| nuclear industry as evil anti-environmental cabals", like
| usual conservative propaganda. How many nuclear reactor
| actually has been shut down in last 5 years? Wait, zero?
| Yeah, the plan is shutting down reactors _after its design
| life_ rather than blindly extending it more and more, which
| is the status quo.
|
| Nuclear fission definitely has lots of advantages, but it
| comes with lots of geopolitical and operational challenges
| especially if you want to use it for decades, or so called
| "sustainability". One of the critical factor of "escaping
| from nuclear fission" was the fact that S Korea is not going
| to have permanent nuclear waste sites anytime soon; everyone
| have been talking about that over 30 years and no political
| party even dare to build the one because in S Korea, every
| single political issue eventually converges to a matter of
| real estate. And you know what? The capacity of the existing
| temporary storage for most plants will be exhausted within
| 5~10 years.
|
| Now we're talking about the so-called "sustainability"; it's
| not about environment or whatever liberal propaganda but the
| dire facts that S Korea will be forced to shut down nuclear
| reactors unless it finds other ways around. The previous
| administration couldn't come up with a good solution so
| decided not to build more reactors. Oh yeah, they didn't even
| dare to shut down those reactors to earn a little bit more
| time. It's not even a propaganda, but just a mediocre
| compromise. Its territory is not big enough to construct just
| a single waste site.
|
| Oh, then why don't we reprocess the waste? And now we're
| talking about geopolitical aspects. The US-Korea atomic
| energy agreement severely constrains what S Korea can do with
| the waste. Unlike many first world countries, it doesn't have
| the reprocessing technology and unlikely have the one unless
| it begins enjoying political tensions with the US.
|
| Nuclear waste is just a tip of iceberg; you're going to find
| an arbitrary many number of operational and economical
| challenges on Nuclear fission reactor. And I also want to
| mention general public reception on nuclear energy, "I trust
| nuclear energy, but not its operators". Yeah, Korean nuclear
| industry is well corrupted to its root and it deserves its
| own reputation. In the era of climate crisis, going to
| nuclear fission seems no-brainer, but the devil is in the
| detail.
| fibonacc wrote:
| The previous administration completely neutered its world
| class nuclear industry and built Chinese solar panels all
| over the mountain side causing landslides and environmental
| issues.
|
| These are just some of the wonderful things the President
| Moon has accomplished.
| [deleted]
| yongjik wrote:
| Maybe I'm biased, but I really don't think "Chinese solar
| panels causing landslides" is a genuine concern for Korea's
| energy policy. That sounds like half a level above
| "Windmills kill birds!"
| lifthrasiir wrote:
| There had been indeed a short period (about a year or
| two) where solar panels did cause environmental issues
| due to the unbalanced incentives. But the government then
| quickly adjusted incentives so it is no longer a concern.
| onlyrealcuzzo wrote:
| > a move which turned out disastrously for the french.
|
| Any more to add?
|
| IIUC, France has one of the highest percentages of nuclear
| energy of any country in the world.
|
| Is this supposed to be bad?
| rjzzleep wrote:
| More than half of their reactors are currently out of
| commission. And Macron was one of the people responsible for
| signing off on the deal that sold off their turbine
| development to GE due to pressure of the DOJ. They were
| talking about buying "it" back. Although I don't know what
| the scope or timeline of the buyback is. I also remember that
| contrary to previous promises GE started dismantling one of
| those factories.
| onlyrealcuzzo wrote:
| IIUC, turbines are not really the bottleneck for nuclear
| power plants.
|
| Sure, they are necessary.
|
| But if France's existence depended on it - I imagine this
| is a problem they could solve relatively easily.
|
| On the flip side, Germany is not going to magically
| generate 80% of their electricity from Nuclear Energy
| anytime soon. Nor the US or Japan or South Korea for that
| matter...
| tomohawk wrote:
| Undergoing maintenance and scheduled to be back online in
| the next couple of months.
| Miraste wrote:
| It does seem like there's a deeper problem if over half
| the reactors are shut down for maintenance at the same
| time.
| fmajid wrote:
| French reactors are all the same design (derived from one
| licensed from Westinghouse). That's how they got the
| economies of scale and were able to ramp up so quickly.
| Unfortunately, that also means a flaw is reproduced in
| all of them. To compound this, the replacements were not
| started quickly enough so the current reactors are
| reaching the end of their design life, and because there
| was not a program to continuously build bew reactirsm the
| industrial skills base atrophied as qualified workers
| like welders retired. And the trifecta is France is
| experiencing its worst drought in recorded history, so
| some of the plants that get cooling from river water had
| to shut down due to low water levels. Even the mighty
| Rhine is a mere rivulet at the moment.
| gquiniou wrote:
| maintenance was late because of covid and then they
| discovered corrosion issues in 6 plants.
| AYBABTME wrote:
| My understanding is that they've decided to push the
| maintenance to this summer to ensure they're available
| for the coming winter.
| onlyrealcuzzo wrote:
| IIUC - the reason so many are down is because of heat and
| low rivers.
|
| This won't be a problem in the Winter when they're most
| needed.
| u320 wrote:
| This is a bit of a myth. The heat wave and water levels
| was a problem, but most of it was maintenance issues
| unrelated to that. It was more a problem of
| mismanagement, and the fact that Macron went into office
| promising to shut down the fleet, making operators start
| to cut down on maintenance. He has now reversed course
| after realising that depending on Russian gas is bad. All
| wind/solar in Europe works by balancing it against
| natural gas or hydro, but the amount of hydro is fixed so
| expanding the wind/solar fleet increases the demand for
| gas. Hence why the renewable poster child Germany is in
| so deep shit right now.
| baud147258 wrote:
| I'm pretty sure summer months are the moment where
| electricity consumption is at its lowest point throughout
| the year, so that's make sense
| azernik wrote:
| They got too much of a monoculture - flaws in one design
| meant a bunch of reactors came up for corrosion repairs
| earlier than expected all at once.
| mytailorisrich wrote:
| I think this has to do with the cooperation deals French
| company EDF signed with Mitsubishi Heavy Industries.
| onlyrealcuzzo wrote:
| What is bad about that?
| airstrike wrote:
| > > a move which turned out disastrously for the french.
|
| > Any more to add?
|
| The Battle of Waterloo?
| Smoosh wrote:
| Reliance on the Maginot Line?
| ncmncm wrote:
| The Maginot Line held.
|
| Germans in Czech tanks went around the end of it, through
| Belgium.
| Aicy wrote:
| Yes, so they were reliant on it. When they couldn't make
| use of if they were swiftly beaten.
| sofixa wrote:
| Which was the whole point of the Maginot line, to channel
| the German advance through Belgium where a defensive line
| was to be established, so it was a success. Everything
| else - reconnaissance, defence of a forrest thought
| impenetrable to mass formations, coordination,
| adaptability to the changing environment (the Germans
| pouring through the supposedly impenetrable forrest),
| officer competency, coordination between army and air
| force, and coordination with the British, were massive
| failures.
| ncmncm wrote:
| The Line was a necessary component of a defense. It just
| needed more, that was not done.
|
| Without Czech armor, the invasion might have failed.
| Predicting the Germans would have the full resources of
| Czechoslovakia would require more prescience than we
| should demand.
| Mordisquitos wrote:
| The Battle of Waterloo was clumsily handled (particularly
| compared to what would have been expected from Napoleon),
| but it is hard to describe it as "a move", as they were
| forced into it, and can hardly be said to have turned out
| "disastrously for the French" (if anything, "for
| Napoleon"). In that context, better example of a move that
| turned out disastrously for the French would be the Russian
| Campaign of 1812.
| [deleted]
| [deleted]
| jmyeet wrote:
| I'd love for commercial fusion power generation to be a reality
| but I'm skeptical that, at a minimum, hydrogen fusion will _ever_
| be practical. The reasons have remained a problem for
| considerable period of time:
|
| 1. Containing a hydrogen plasma involves containing a superheated
| turbulent fluid. This is inherently unstable that will be
| sensitive to very minor defects;
|
| 2. A superheated plasma produces a lot of high velocity
| particles. Those not contained by magnetic containment tend to
| destroy the container (ie "neutron embrittlement"); and
|
| 3. Possibly the biggest problem of all: neutrons represent energy
| loss by the system and there's no currently viable way of solving
| this problem.
|
| To solve (2) and (3) various groups research so-called
| "aneutronic" fusion. I put that in quotes because it's just a lot
| less neutrons generally, not no neutrons.
|
| Helium-3 fusion is one possibility but He-3 is exceedingly rare.
| The best source may be from the solar wind being collected on the
| Moon's surface. As you can imagine that presents it's own set of
| challenges to mine, contain and return.
|
| Hydrogen fusion uses heavier isotopes of hydrogen (ie deuterium
| with 1 neutron and/or tritium with 2). Why? Because we currently
| need these neutrons to feed the fusion reaction.
|
| And after all this we extract heat to boil water to turn a
| turbine. This too adds to cost and complexity.
|
| Personally I think the future of humanity's energy production is
| space-based solar power collectors.
| DennisP wrote:
| If it's aneutronic fusion, you don't need a turbine. You have
| fast-moving charged particles, and can probably figure out a
| way to do direct conversion. Helion has already demonstrated it
| in their latest reactor.
|
| They use a hybrid D-D/D-He3 reaction. The He3 is the waste
| product of the D-D reactions. They say the combination will
| release only 6% of its energy as neutron radiation, which is
| why they can skip the turbine.
|
| (I'm also a fan of space solar though.)
| boringg wrote:
| Full steam ahead!
| stevage wrote:
| Steam behind. Fusion ahead.
| boringg wrote:
| Um actually the fusion then uses that heat to create steam
| which produces electricity...
|
| So fusion then steam.
| fibonacc wrote:
| If they can pull this for 30 seconds in 2022, they can do 30
| minutes by 2025, 30 hours in by 2027 and then 30 weeks by 2030
| being very optimistic here.
|
| Right now things are bad in this world and will get worse but the
| future is filled with abundance and new levels of comforts not
| seen in human history.
| alliao wrote:
| Hope I get to see it before I die... unlimited energy to combat
| climate change would be pretty damn epic.
| ncmncm wrote:
| Fusion will not provide unlimited energy. And not even
| affordable energy. There is nothing to see here but
| physicists having fun with other people's money.
| ajdegol wrote:
| Mate, I've read a few of your comments here. Are you some
| sort of anti-fusion shill?
|
| Physicist having fun with other people's money?! On top of
| the fact that this demo reactor costs a fraction of the
| _development_ cost of the F-35.
|
| Eric Weinstein: "We can't afford to pay these people. We
| can't afford to give them an accelerator just to play with
| in case they find something at the next energy level, these
| people created our economy. They gave us the rad lab and
| radar, they gave us two atomic devices to end World War Two
| that created the semiconductor and the transistor to power
| our economy through Moore's Law as a positive externality
| of particle accelerators that created the World Wide Web.
|
| And we have the insolence to say, why should we fund you
| with our taxpayer dollars? Now, the question is, are you
| enjoying your physics dollars?"
|
| So, how are you having fun with your physics dollars?
| ncmncm wrote:
| These are all different physicists. The ones doing other
| things are competing for the money being spent on the
| fusion projects instead.
|
| I would rather the other ones get it, because maybe
| something of value might come from that.
|
| That said, plasma fluid dynamics physicists are
| chronically underfunded, and they can often use money
| from fusion projects for their experiments. I never
| begrudge money to plasma fluid dynamics physicists. But
| we shouldn't expect to get useful fusion out as a result.
| aeternum wrote:
| It does seem like the cost vs. reward of fusion tech is
| ridiculous at this point.
|
| I'm all for new tech but we should at least try to project the
| cost to build a working fusion power plant. Fusion not only has
| to work, it has to be at least somewhat cost-competitive with
| other forms of energy generation.
| notamy wrote:
| > Fusion not only has to work, it has to be at least somewhat
| cost-competitive with other forms of energy generation.
|
| Perhaps silly, but I wonder how this comparison would shape
| up if we were capable of calculating reasonably-accurate
| long-term figures about effects of pollution, mining for
| resources, construction costs, etc. in the process of
| producing each form of energy. I'm really curious what that'd
| look like.
| fibonacc wrote:
| true as elon musk says it won't be economically viable for
| quite some time but fusion is the right step, what I'd be
| interested is if they can miniaturized to fit on rocket
| payloads.
| Bolkan wrote:
| Unless they hit a fundamental limit. Think speed of light.
| DubiousPusher wrote:
| Was this a successful ignition?
| enviclash wrote:
| Are there game-changing implications for this result?
| tinco wrote:
| Nope, it's just the expected gradual progression to the game-
| changing result that fusion eventually is going to be.
| ncmncm wrote:
| No. Progress toward cancellation, as its gross impossibility
| fades into gross impracticality and grossly extreme cost.
|
| You can safely ignore all future fusion announcements.
| ajdegol wrote:
| It's not like it's theoretical, it powers the sun; it's
| responsible for all atoms in the universe. It's essential for
| the long term survival of the species.
|
| "Grossly extreme cost"? Shell made more money than ITER costs
| in the Q2 of 2022
|
| https://www.shell.com/investors/results-and-
| reporting/quarte...
| ncmncm wrote:
| "Grossly extreme cost" refers to what any actual fusion
| plant would cost to build and operate.
|
| ITER, even at tens of $Bs, is small potatoes compared to
| what a real plant would have to cost.
| ncmncm wrote:
| Hint 1: _nobody_ is working on fusion as it happens in the
| sun.
|
| Hint 2: the sun already works. Solar panels already work,
| and are cheap and getting cheaper.
|
| Hint 3: ITER is not a power plant. It is not even planned
| to ever produce so much as one kWh of electrical energy. It
| will burn GWh, if ever finished.
|
| Hint 4: a working fusion power plant would necessarily cost
| many times as much to operate as a fission plant of the
| same capacity.
| ajdegol wrote:
| Hint 1: Nobody working on something isn't solved by not
| spending money on it.
|
| Hint 2: We should invest heavily in solar; they aren't
| exclusive. I am a massive, massive fan of solar, and
| tidal, and hydro, and wind.
|
| Hint 3: ITER was never intended to be a power plant. This
| is a hacker forum, one assumes you know about iteration.
|
| Hint 4: That's an untested assertion which I would
| dispute, and the cost will come down with more research
| and experience.
|
| Also, I'm taking exception with you regarding the cost.
| This is pittance for humanity to spend.
| ncmncm wrote:
| You do not seem to grasp the gravity of the current
| climate crisis. Fooling with fusion now is like trying to
| call a car dealer at midnight in a storm when you have
| crashed your car into a tree.
| tonymet wrote:
| a question for nuclear experts : what does the unstable fusion
| state look like ? is there a catastrophic risk and now severe is
| it ?
| sounds wrote:
| Pretty much overheating something, leading to a relatively
| boring shutdown and a long, potentially costly repair.
| kumarski wrote:
| Fusion is pointless.
|
| Fusion reactors make nuclear power plants marginally smaller.
|
| Dispatch and transmission costs are still a thing.
| ncmncm wrote:
| Fusion reactors would have to be enormously bigger than fission
| plants. And cost correspondingly more both to build and to
| operate.
| kumarski wrote:
| There's no net benefit to fusion.
|
| Dispatch and transmission are a thing even if all the
| software developer/ECE/Physicist folks downvote my comments.
| ajdegol wrote:
| "There's no net benefit to fusion." There's no net benefit
| to abundant energy... yes, I can't think of any.
| pfdietz wrote:
| Not if it's as expensive as it's likely to be from
| fusion, no.
| ajdegol wrote:
| You don't get them cheaper by never building them; the
| energy density of fusion is far higher than fission and
| doesn't have any danger of runaway chain reactions.
| pfdietz wrote:
| Neither of those is a significant advantage.
|
| Also, I'm not a fan of tinkerbell engineering, where
| anything is possible if we just believe hard enough.
| ncmncm wrote:
| Fission doesn't have a thousand tons of lithium hydride
| just itching to explode in flames and gas the
| surroundings with that much drain opener.
| Kukumber wrote:
| China managed to reach 120 millions degC for 1000 seconds last
| year already
|
| https://news.cgtn.com/news/2021-12-31/China-s-artificial-sun...
| motokamaks wrote:
| They managed to do it all separately in separate experiments.
| This is the first time both stability & temperature were
| achieved simultaneously.
| Kukumber wrote:
| Oh you are right, important detail indeed
| djyaz1200 wrote:
| What if the stars in the galaxy are the remnants of civilizations
| fusion reactor gone wrong ;p
| kushan2020 wrote:
| What if stars also experience global warming ?
| Aaronstotle wrote:
| What if stars are sentient beings?
| wizofaus wrote:
| Greg Matloff would like a word with you.
| fb03 wrote:
| What if stars are nothing but accumulated powder that brushed
| against itself for too long to spark up?
| DennisP wrote:
| What if the solar system is an atom in a giant brain?
| [deleted]
| gajus wrote:
| What is the significance of this?
| groby_b wrote:
| Second sentence from The Fine Article: "While the duration and
| temperature alone aren't records, the simultaneous achievement
| of heat and stability brings us a step closer to a viable
| fusion reactor - as long as the technique used can be scaled
| up."
| zxcvbn4038 wrote:
| What? No reactor in every home? Those house of the future
| films lied to me in every way.
| stevage wrote:
| That's what solar plus battery is for.
| uwuemu wrote:
| Good luck trying to "scale up" (at least in the near future).
| Tokamaks are only getting to be "scaled up" now, after pretty
| much decades, and basically only thanks to ITER (factor of
| ten plasma volume compared to the second largest tokamak).
| And ITER is a megaproject comparable (both in budget and
| time) with the SLS program. Maybe even more expensive
| (depending on if you believe the official number, 22bn EUR,
| or the unofficial estimate, 40bn EUR) and DEFINITELY more
| complex with far more cutting edge science (plasma physics,
| material science...), technology, and engineering required.
|
| If ITER succeeds (proves that fusion in a magnetic
| confinement device can be used to produce net electricity and
| it's "just" a matter of scaling things up that is holding
| fusion back), then sure, investors are going to line up, even
| for alternative designs. Fusion will be all the rage. But
| until then, I doubt anyone is scaling anything fusion-related
| up. Well and if ITER fails, then we are all fucked, and we
| can turn the fusion "are we there yet" clock back 50 years.
| klabb3 wrote:
| Isn't total cost per reactor more constraining than cost
| per Wh for these mega projects? Say you spend $10B on a
| reactor that produces essentially free energy. You're still
| limited by plant lifetime, maintenance and crucially
| transportation of that energy - just breaking even would be
| a challenge in many locations. Thus, we have to have many
| plants distributed, similar to today's fission, at
| somewhere in the 500MW range per reactor (give or take an
| OOM).
|
| In short, we have diminishing returns for giant reactors,
| and instead need to have plants that can be mass produced,
| fast.
| samhain wrote:
| Have you taken a look at MITs SPARC reactor? I'm always
| skeptical of comments that only reference ITER, since it's
| very old news at this point, and there have been a plethora
| of innovation beyond ITER in just the last few years. The
| REBCO tape, and being able to get 10x magnetic field
| strength compared to ITER in a 3x smaller diameter seems
| like fairly significant progress to me.
| terrorOf wrote:
| AFAIK, China has record for temperature and duration however
| it is known as China heated up electron rather than heating
| up ion which is more proper.
| tinco wrote:
| I hadn't realized that was a different kind of record (150M
| degrees for over 1000 seconds). I suppose the ions have
| more mass than the electrons so that temperature is harder
| to maintain, but I have no idea about the physics of having
| them not heat up at the same rate.
|
| BTW I had to vouch for your comment to reply because you
| have a history of making short and sometimes brusque
| comments and HN has punished you for it. If you would make
| slightly longer comments in the future more people will
| engage with you and it will be more fun for you.
| npunt wrote:
| It's just the new hotness
| random314 wrote:
| Alright, take the upvote!
| mrtri wrote:
| redwood wrote:
| S. Korea's technology sophistication is so inspiring
| [deleted]
| TedShiller wrote:
| While impressive, that is the easy part. Anyone can heat
| something up given enough energy put into the system. The hard
| part is producing energy on a net basis.
| taylorbuley wrote:
| > Malware and Phishing > This site is blocked because it is a
| known security threat. Please contact your network administrator
| to gain access.
|
| Higher quality source:
| https://www.newscientist.com/article/2336385-korean-nuclear-...
| [deleted]
| kushan2020 wrote:
| Does anyone know how do scientists measure such high
| temperatures?
|
| I doubt a regular thermometer will scale at such levels.
| femto wrote:
| Measuring the temperature is the same as measuring the average
| energy of particles in the plasma, which is the same as
| measuring the average speed of the particles. Basically you do
| that by measuring radiation, doing it in several different
| ways, so you can test the accuracy of your measurement. This
| article gives an overview:
|
| https://www.scienceinschool.org/article/2013/fusion-4/
|
| Incidentally, the plasma is of such low density (ie. few
| particles) that it has little stored heat energy. As soon as
| the plasma touches anything it cools down and fusion stops.
| You're unlikely to get a mushroom cloud out of today's fusion
| reactors, as there is just not enough stored energy in them.
| (Might that change if they are scaled to the point where large
| amounts of energy can be extracted, a bit like the bang out of
| a large charged capacitor?)
| ncmncm wrote:
| When the thousands of tons of lithium hydroxide catch fire,
| you will notice.
| ncmncm wrote:
| Oops, autocorrect strikes again.
|
| The blanket is lithium hydride, not hydroxide.
|
| Some people talk about adding beryllium.
| pfdietz wrote:
| Having lithium hydroxide catch fire would be quite a trick.
| Are you mixing it with chlorine trifluoride?
| ncmncm wrote:
| Lithium hydride. The oxide is what you get after it
| explodes.
| femto wrote:
| What's lithium hydroxide used for in fusion reactors?
|
| Edit: A bit more searching turned up an answer. It's a
| neutron absorber. So it's used as a shield to stop the
| neutrons leaving the reactor?
| ncmncm wrote:
| The lithium + neutrons would breed the tritium you need
| for fuel to burn tomorrow.
|
| Extracting parts-per-billion of tritium distributed
| throughout thousands of tons of hot, brittle,
| radioactive, super-flammable LiH would be no picnic.
| Melting it probably would not make that easier.
|
| Fortunately, no one will need to.
| wrp wrote:
| > ...the plasma is of such low density...
|
| I believe the chambers are operated at a pressure of
| 1/10,000th of an atmosphere.
| la64710 wrote:
| This is why California is so freaking hot this week !! Crazy
| DennisP wrote:
| I think you're joking, but I'll still point out that it's not
| actually much heat. The atoms of fusion fuel move very fast,
| but there aren't many of them.
| sai_c wrote:
| Could someone please enlighten a physics noob?
|
| As i understand it, nuclear fusion could (as soon as really
| achieved, i.e. there exist commercial plants) provide more energy
| than we are currently producing by all other methods. And if we
| can produce it, I have no doubt we would use more and more
| energy.
|
| Which would mean that all this energy must end up somewhere
| somehow. What I would like to know is, don' we then (just in
| another form) contribute to the heating of the planet again? Are
| there any studies/theories about that? What would the impact of
| the ever increasing energy release/production be?
| twic wrote:
| > 'Don't blame me,' said Poole, fighting back gamely after one
| round of criticism. 'Anyway, see what a mess the twenty-first
| century made.'
|
| > There was a chorus of 'What do you mean?'s around the table.
|
| > 'Well, as soon as the so-called Age of Infinite Power got
| under way, and everyone had thousands of kilowatts of cheap,
| clean energy to play with - you know what happened!'
|
| > 'Oh, you mean the Thermal Crisis. But that was fixed.'
|
| > 'Eventually - after you'd covered half the Earth with
| reflectors to bounce the Sun's heat back into space. Otherwise
| it would have been as parboiled as Venus by now.'
|
| -- 3001: The final Odyssey, Arthur C. Clarke
|
| Accuracy not guaranteed!
| sai_c wrote:
| Made my day :-).
| TaylorAlexander wrote:
| It's a good question. I recall someone saying that the amount
| of direct heat produced by energy generation is very small
| compared to the heat captured from the sun by the greenhouse
| effect.
|
| Also I don't think it's true that commercial fusion power
| plants would in the near term produce extraordinarily high
| energy levels compared to a large hydroelectric or fission
| nuclear power plant. The thing that's great about fusion is
| that it requires very little fuel and doesn't produce nuclear
| waste.
| sai_c wrote:
| I hope i did not understand you wrong, but what I meant was
| the following. We create electric energy from source X. The
| electric energy is mutated to heat, or mechanical energy or
| what not (computers produce heat, electric cars mutate it
| into kinetic energy and so on). Energy is never destroyed, it
| just changes its form. So if we produce/consume more energy
| than now (yes that's just theoretical) would that contribute
| to climate change in a significant manner?
| DennisP wrote:
| Eventually, yes. Right now waste heat is a tiny fraction of
| excess greenhouse heating, but if we kept multiplying our
| energy usage by a couple percent per year, we'd boil the
| oceans in four centuries.
|
| https://dothemath.ucsd.edu/2012/04/economist-meets-
| physicist...
|
| If we invent fusion, I think we could grow exponentially
| for quite a while, but it'll mostly happen in space.
| Controlled fusion makes a really great rocket.
| mikeInAlaska wrote:
| "An error occurred during a connection to www.shiningscience.com"
|
| Was it hosted at the facility?
| rkagerer wrote:
| The Wikipedia article on Tokamaks is refreshingly approachable:
|
| https://en.m.wikipedia.org/wiki/Tokamak
| Rackedup wrote:
| "as long as the technique used can be scaled up."
| teaearlgraycold wrote:
| OOF
| greyhair wrote:
| Web link is flagged by Avast has containing a malware payload.
| holografix wrote:
| Wrap fusion reactor in huge domes of highest efficiency possible
| modified photo voltaic curved panels aimed at capturing decaying
| neutrons producing photons.
| eek2121 wrote:
| 20 more years folks! Move along...
| pontifier wrote:
| Fusion? I've got a new and different design that needs testing.
| If anyone is interested there is more information at
| http://www.DDproFusion.com
| j15e wrote:
| As a newbie in nuclear fusion, this explanation is the most
| interesting part:
|
| > Lee Margetts at the University of Manchester, UK, says that the
| physics of fusion reactors is becoming well understood, but that
| there are technical hurdles to overcome before a working power
| plant can be built. Part of that will be developing methods to
| withdraw heat from the reactor and use it to generate electrical
| current.
|
| > "It's not physics, it's engineering," he says. "If you just
| think about this from the point of view of a gas-fired or a coal-
| fired power station, if you didn't have anything to take the heat
| away, then the people operating it would say 'we have to switch
| it off because it gets too hot and it will melt the power
| station', and that's exactly the situation here."
| Schroedingersat wrote:
| So we think about the engineering problem and reject the entire
| concept on that basis.
|
| Even if I give you a magic box full of near vacuum 100 million
| degree plasma that emits 1MW/m^3 in the form of neutrons
| whenever you want as long as you stop it from touching the
| sides with supercooled magnets. How do you turn that into a
| remotely viable power station?
|
| Just the heat exchanger and steam turbine portion is going to
| be uneconomical against renewables+storage.
| ncmncm wrote:
| Yes. Just just keeping a steam turbine up and running,
| completely ignoring where the heat comes from, costs more
| than both building out _and_ operating wind and solar.
| Schroedingersat wrote:
| TEGs are pretty neat, but the temperature and energy flux
| is very hard on the materials.
|
| If only there was some way to get energy from a fusion
| reaction via a semiconductor junction by running them in
| parallel at low temperature rather than in series at
| extremely high temperature, and a long way away so the
| neutrons could thermalize and you could absorb much easier
| to handle photons. Oh well.
| pmayrgundter wrote:
| I'm exploring such a concept, NanoFusion.
|
| A study device and thinking from first principles about
| the reaction.
|
| There are higher energy reactions like proton-boron that
| emit only light and charged particles. Eric Lerner's
| Focus Fusion approach taught me about that.
|
| I'm looking at parallel delivery of single photons and
| how that scales as laser systems develop. Lasers
| themselves are on an exponential curve, so that seems
| promising.
|
| Fusion batteries would be cool!
|
| https://docs.google.com/document/d/1B5maRx9w0ahQTqSe6UZ56
| rd0...
| ncmncm wrote:
| Sustained p-11B fusion might not be possible: the gamma
| photons carry away too much energy, and nothing can
| reflect them back.
|
| But if it could be made to work, it would be a better
| prospect than D-T.
| pmayrgundter wrote:
| Two ideas:
|
| 1) don't try to achieve a chain reaction, but do single
| atom reactions and fully cycle the energy. Simpler to
| think about, and raw energies add up (see link).
|
| 2) if chain reaction needed, orient the reaction to aim
| the outputs towards their secondary targets e.g. with a
| crystal lattice fuel package.
| ncmncm wrote:
| Where do the photons come from?
| Schroedingersat wrote:
| The usual place. Surround your fusion reactor in a very
| thick blanket of opaque hydrogen plasma so the neutrons
| can bump into something.
|
| Contain the whole thing in some kind of force field (if
| only there was some alternative to the EM force for this
| purpose), then when the photons hit your photon electric
| generators you get electricity.
|
| If you arrange things such that the outside of the opaque
| hydrogen blanket is about 5800 Kelvin and your photon-
| electric generator panels are spread out in parallel
| to...let's say about a kilowatt of energy per square
| metre they should last a couple of decades and your
| efficiency will be okay, maybe around 20-30%
|
| There. Fusion power plant invented. Sadly it's just a
| pipe dream though because we couldn't roll it out without
| first waiting for a stable fusing plasma source on earth.
| ncmncm wrote:
| How does neutrons bumping protons produce light?
| Schroedingersat wrote:
| It heats them up (The joke is I'm describing the sun and
| solar panels as the end state of trying to overcome the
| technical hurdles of building a heat engine to extract
| electricity from fusion if you're not just playing
| along).
|
| Jokes aside, TEGs are pretty neat. In addition to
| harvesting what is currently waste heat in someplaces or
| having applications in geothermal or solar collectors
| they might even make fission not-stupid. Can't forsee any
| way fusion works as practical power generation this
| century though. It has worse power density than chemical
| and much higher temperatures to deal with and much higher
| neutron flux than fission as well as needing massive 2
| kelvin magnets right next to the 100 million degree
| plasma that explode if they warm up to 3 kelvin.
| ncmncm wrote:
| Solar fusion doesn't produce neutrons hot or otherwise.
| It produces gamma rays, helium nuclei, and neutrinos.
| DennisP wrote:
| Sure, as long as you skip storage. Batteries are really
| expensive if you're using enough to get through windless
| nights instead of just compensate the duck curve. Long-
| distance transmission is expensive too, and to get through
| winter you need either huge storage or lots of
| overcapacity. It all adds up.
|
| At this point someone usually says "we don't need batteries
| for long-term storage, we can just make hydrogen and burn
| it later" but then oops, you're back to using a turbine.
| ncmncm wrote:
| It is correct that batteries are the most expensive
| storage. One corrolary is that other storage is cheaper.
| Another is that other methods will be used instead.
|
| Storage is an integral part of a renewable-powered grid.
| It is figured into all the cost analyses. Insisting
| otherwise is promoting known falsehoods. Lying is
| unwelcome here.
| DennisP wrote:
| Hence my second paragraph.
|
| The only other major option is using pumped hydro for
| storage, but not every region has the geography for it.
| ncmncm wrote:
| Pumped hydro is very far from the only alternative to
| batteries. But you have been told that before, too.
| DennisP wrote:
| "Hence my second paragraph" which was this:
|
| > At this point someone usually says "we don't need
| batteries for long-term storage, we can just make
| hydrogen and burn it later" but then oops, you're back to
| using a turbine.
|
| There are various experimental options too but I don't
| think any have deployed at scale, so their costs are
| uncertain. And some of them, like thermal storage, will
| still use a turbine.
| ncmncm wrote:
| Turbines cost less to operate part-time than full-time.
| One operated 4 hours / day, or one day / week, costs a
| lot less than one run continuously.
| DennisP wrote:
| I'm gonna need a source on that. It seems to me that
| turbine cost is mainly capital cost, and if you're not
| running it continuously then your cost per kWh is
| _higher_.
|
| After all, that's the argument you renewables folks make
| when you say nuclear plants can't load-follow
| economically. So tell me why a turbine run intermittently
| is cheaper, and prove it with a source.
| ncmncm wrote:
| Allow me to invite you to look up steam turbine overhaul
| cost and frequency. Do mothballed turbines need frequent
| overhauls? Or will they need overhauls after N hours' use
| at intensity Y, or after M > N operated at intensity X <
| Y?
|
| Steam turbines are a substantial fraction of nuke
| operating cost, but far from the only substantial cost.
| DennisP wrote:
| An idle turbine also isn't earning revenue.
|
| I haven't found specific numbers on steam turbines, but
| this pdf says a gas turbine's maintenance cost over 30
| years is 3 to 4 times the capital cost:
|
| https://www.gasturbine.org/papers/GTA%20Comments%20on%20R
| MRR...
|
| So taking the worst case, capital plus maintenance for a
| continually-running turbine is 5X its capital cost, to
| get 30 years of power output. For each year of power, the
| total cost is 5/30 or 1/6 of the capital cost.
|
| Now lets take your 4 hours/day example. That's 1/6 as
| much running time, so only 5 total years of power output.
| It's also 1/6 as much maintenance cost, so maintenance is
| 4/6 of the capital cost, for a 30-year total cost of 1.66
| times capital cost. Total cost per year of power is
| 1.66/5 = 1/3 of the capital cost.
|
| That puts the cost per kWh for energy storage at double
| the cost of the continuously-run turbine.
| baby wrote:
| Similar to how energy is extracted from fission reactors
| currently: the heat is used to boil water which makes large
| turbines spin and produce energy. It's dumb engineering. (I
| don't mean that in a bad way.)
| Gwypaas wrote:
| Could be interesting if they couple it with a Closed Cycle
| Gas Turbine [1] and a tiny steam plant, like the gas CCGT
| plants of today. Then the heat engine part should see
| similar, or even higher, efficiencies compared to gas based
| CCGT plants.
|
| Boiling water using the Rankine cycle [2] and it will be as
| dead in the water as nuclear and coal is today.
|
| A thing to keep in mind though is that it is very hard to
| compete with the engineering of an axle straight into a
| generator like wind turbines or a solid state system like
| solar PV. Working fluids, cooling loops and what not are
| awful to build and maintain.
|
| [1]: https://en.wikipedia.org/wiki/Closed-cycle_gas_turbine
|
| [2]: https://en.wikipedia.org/wiki/Rankine_cycle
| spoils19 wrote:
| Coal is very much alive in prospering countries, and I
| stand with other conservatives in that we don't need new
| fancy energy production.
| mlazos wrote:
| I suppose I'll bite here. We don't need "fancy" energy
| production as Southern California and the Midwest becomes
| uninhabitable, you serious? Coal power should be dead in
| the water if it isn't. It's bad for workers, bad for the
| air we breathe, water we drink, bad for the people who
| live around plants. That has been well established. It
| actually kills more people than nuclear, solar and wind
| combined. There's no redeeming quality to it other than
| being plentiful and cheap. It shouldn't be cheap based on
| the externality of the destruction it causes here and
| around the world.
| spoils19 wrote:
| 13of40 wrote:
| Find me a dentist who recommends flossing but who isn't
| one of those parrots that advise brushing or regular
| teeth cleanings.
| aidenn0 wrote:
| This guy [1] is definitely an independent thinker and
| pretty regularly beats the "air quality" drum. Burning
| coal puts a massive amount of particulate matter into the
| air. That alone should disqualify it.
|
| 1: https://dynomight.net/air/
| didericis wrote:
| It being plentiful and cheap is a pretty damn important
| and redeeming quality.
|
| In most western countries we can afford to transition to
| other solutions, and it is far healthier for both the
| people around it and the environment, but I don't think
| most of the people on this site really understand the
| ramifications of not having cheap reliable power. There's
| a reason people left the farms and flocked to dirty
| hellish cities during the industrial revolution and still
| flock to cities and build coal plants today. It's less
| hellish than living without reliable modern amenities.
|
| Southern California and the Midwest aren't going to
| become uninhabitable even if we continue pumping out as
| much CO2 as we are currently. I know of no reasonable
| projections that predict anywhere near the human cost of
| just shutting off power completely if it's not clean like
| people seem to want to do.
|
| That does NOT mean we can't reduce CO2 emissions _while_
| meeting increasing energy demands. But we should be
| striving to do both. And given a choice between living
| next to a coal plant and having reliable lighting,
| heating, air conditioning and food refrigeration or
| living next to a clean but unaffordable and unreliable
| plant, most people would choose the coal plant. _We've
| been running that experiment globally since the
| industrial revolution, the answer is clear_. Even when
| taking the health effects and climate change projections
| into account, _that choice would be reasonable_. Dying of
| cold, dying of disease due to unrefrigerated food, dying
| due to inability to call for help... these are all things
| very distant from the minds of most people fortunate
| enough to be on this site. They are very real
| ramifications of not having reliable power. And those
| severe ones I just mentioned are just the tip of the
| iceberg.
|
| Lets just please, please, _please_ finish the new stuff
| before turning the old stuff off. Build as many solar
| farms and wind turbines and nuclear and hydro and battery
| parks and hydro batteries and natural gas lines as we
| need, and only turn the old stuff off _when we're
| actually ready_. If we turn off everything not clean
| preemptively we're going to kill way more people than
| climate change. If we were reasonable and sought to
| actually solve emissions problems as fast as possible
| there is no reason not to aggressively pursue wind AND
| solar AND hydro AND nuclear fission AND natural gas.
|
| It's sad I can make this prediction about your opinion,
| but I'm assuming you are probably not an advocate of
| fracking or nuclear power or hydro. Please correct me if
| I'm wrong. A lot of people apocalyptic about climate
| change are quite picky and refuse to pursue solutions
| that don't conform to a perfect vision of a star trek
| like future where everything looks like the apple campus.
| It's delusional.
|
| It speaks to the privilege of those advocating green
| energy "at all costs" (which is not actually at all costs
| and maximally translates to "at the cost of the poor" due
| to the aforementioned pickiness) and reflects a severe
| lack of appreciation for the ramifications of less
| reliable and more expensive power on the poor.
|
| The fact that most people on this site are surrounded by
| opulence and excess is creating a severe disconnect with
| the reality of the wider world. That default reality is
| that the only reason the climate isn't killing way more
| people _in the here and now_ is cheap power.
| mlazos wrote:
| > It's sad I can make this prediction about your opinion,
| but I'm assuming you are probably not an advocate of
| fracking or nuclear power or hydro. Please correct me if
| I'm wrong.
|
| Lol yeah you're wrong. We're on HN after all, everyone
| loves nuclear. Fracking is also horrible for the
| environment and for climate change. Most wells leak
| methane which is a 6x worse greenhouse gas than CO2.
| Hydro and nuclear are fantastic, although we've dammed
| most places we can in the US already. Anyway I'm against
| coal, the climate is a _cost_ of coal, it isn't cheap for
| society. I'm for investing in doubling the nuclear
| capacity of this country to eliminate coal completely. Or
| spend the trillion dollars we've dumped on wars to build
| a superconducting power grid and save the transmission
| waste. Also as others have said your argument is a
| ridiculous straw man. Nobody is talking about going back
| to the Stone Age. Just talking about how to build cleaner
| sources of energy. If the weather of the past year hasn't
| convinced you of the necessity of this, I'm afraid for
| the future of the world.
| didericis wrote:
| I'm glad you are willing to invest in other forms of
| clean energy.
|
| That argument is not a straw man. I know very few _want_
| to go back to the stone age (some radicals do), that's
| not my argument. A lot of people vastly overestimate the
| ease of transitioning and are making laws and goals and
| plans that are wildly optimistic and out of touch that
| will in effect lead to unstable grids and more people
| without power. No one sane wants that, but that's
| _already happening_ because a lot of places that have
| been aggressive about transitioning have done it poorly
| and without proper backup power generation options.
|
| If COVID hasn't convinced you rushed and panicked
| centralized interventions make things worse, and you're
| willing to engage in even more of the kind of massive
| disruptions that we've only begun to see the full effects
| of because of a heatwave, you're likely to kill more
| people with rushed intervention:
| https://nypost.com/2017/07/10/heat-death-hysteria-the-
| wrong-...
|
| I meet a lot of people that are dogmatic about wind and
| solar and think it'll work by itself and that the whole
| world needs to transition to that alone right now. In
| combination with other sources, in the US and rich
| countries we can afford to build all the clean energy we
| need, if all options are actually on the table. But doing
| that globally and doing it too fast will kill people.
| Dylan16807 wrote:
| > It being plentiful and cheap is a pretty damn important
| and redeeming quality.
|
| If you want to talk about "redeeming" then you need to
| include externalities, and those are pretty bad for coal.
|
| > the human cost of just shutting off power completely if
| it's not clean like people seem to want to do.
|
| Nobody wants to do that, stop being weird.
| didericis wrote:
| Germany _already did that_. They shut down a whole bunch
| of power plants to meet emissions quotas thinking they
| could meet demands with renewables. They made their grid
| fragile and dependent on the Russians, and now they
| can't. They're planning on rationing and building warming
| shelters: https://m.dw.com/en/german-residents-make-
| plans-amid-fears-o...
| ncmncm wrote:
| Not what happened. Other options were worse.
| didericis wrote:
| That is what happened, and you saying "other options were
| worse" is precisely the point I'm making.
|
| Worse according to who? Climate activists? Or people who
| are going to freeze to death because those "worse"
| options weren't kept online?
| wpietri wrote:
| > Nobody wants to do that, stop being weird.
|
| It did strike me as a pretty egregious straw man. I don't
| think I've ever heard anybody argue for just turning off
| coal plants and sitting in darkness, certainly not the
| poster being replied to.
|
| In the last 20 years, the percentage of US energy coming
| from coal has fallen in half. Eliminating is entirely
| achievable.
| didericis wrote:
| People don't think that's what they're arguing for, but
| that's what happens when you go green too optimistically
| and aggressively. If you sacrifice reliability and
| robustness for being green, your grid becomes vulnerable.
|
| From what I understand it seems reasonable to get rid of
| coal in the US over a reasonable time frame with
| appropriate replacements. I'm not arguing in favor of
| coal. I'm arguing in favor of going with cheap reliable
| energy and whatever the best and actually practical
| solutions are for a given area.
|
| The fact that coal has fallen by half in 20 years doesn't
| mean the other half is just as easy, either. You need a
| certain amount of supplemental power at night, during bad
| weather, during usage spikes, etc. The remaining
| percentage of coal use is going to be more and more
| concentrated in the supply areas that are harder to
| replace. That doesn't mean it can't all be replaced or
| that we shouldn't pursue replacing all of it, all I'm
| advocating is for a sane transition that takes practical
| constraints like that into account and doesn't get
| perfectionistic about solutions. Frankly I don't often
| see considerations like that being made, I see a lot of
| hysterics and dogmatic assertions about how everything
| needs to be solar panels and wind turbines yesterday and
| everyone who wants moderation or other green solutions
| and more gradual phase in is a greedy oil shill.
| wpietri wrote:
| > I'm arguing in favor of going with cheap reliable
| energy and whatever the best
|
| Then you're not doing a very good job of it. For all that
| you accuse others of "hysterics and dogmatic assertions",
| I think your posts earn that label way more than the
| comments you replied to.
| ncmncm wrote:
| The transition will perforce be very far on the side of
| what you call "sane", to a pathological degree. There is
| no merit in arguing for what must certainly happen
| anyway.
| notacop31337 wrote:
| Hey mate, I've been going through a bout of depression
| recently, and I wanted to thank you for your comments on
| HN, this one and many of your other posts have made me
| laugh so much and have put a proper smile on my face, I'm
| sitting at my desk in such a good mood. I enjoy your form
| of comedy.
|
| Thank you.
| u320 wrote:
| If you think nuclear is dead in the water you haven't
| really been following where the energy debate is heading
| these days. Especially in Europe, where we no longer have
| the luxury of plugging the holes left by renewables with
| gas.
| hammock wrote:
| Why can't you use natural gas in Europe?
| ben_w wrote:
| Boycotting one of the bigger suppliers.
| DFHippie wrote:
| One of the biggest suppliers is boycotting them. Russia
| has turned off the gas to try to break the European
| resolve to assist Ukraine.
| ben_w wrote:
| Also true. It's a two-way boycott.
| [deleted]
| [deleted]
| [deleted]
| hammock wrote:
| Is that self-inflicted or do they have to boycott it?
| ben_w wrote:
| "Have to" is ill defined. On paper they _could_ say
| "leaving the Soviet union was a terrible idea, we want
| back in" but many have lived experience of living under
| soviet (or soviet-allied) rule and hated it. On paper
| they _could_ give Russia a ultimatum of "withdraw or
| face open war", but Russia has more nukes and they may
| well still function. Boycotts are the current choice.
| mschuster91 wrote:
| > Especially in Europe, where we no longer have the
| luxury of plugging the holes left by renewables with gas.
|
| We don't have the luxury to wait on nuclear either. A
| large part of the current French electricity crisis is
| "thanks" to the cost and time budget overruns of
| Flamanville - they had gambled on Flamanville being ready
| in time to replace the old unreliable clunkers that,
| surprising nobody, now have massive corrosion issues.
|
| The solution is to massively over-build on renewables -
| wind and solar most obviously as well as trans-
| continental ultra-high-voltage links, but also biogas
| plants that convert the millions of tons of cow dung and
| other bio waste into gas that can then be used during low
| availability of renewable electricity. On the other side
| we also desperately need actually smart grids and
| consumers that can dynamically act based on the power
| available in the grid.
| Gwypaas wrote:
| Nuclear has a 15-20 year delay from political decision to
| generating power. Color me surprised if there's still an
| ongoing energy crisis in Europe by 2037-42.
| Filligree wrote:
| That delay is, itself, mostly due to political reasons.
| It may be interesting to see what will happen.
| rdevsrex wrote:
| Well the Energy Department just approved a new nuclear
| design for testing. Not sure how long it was in the
| works. If there is enough money to be made, you better
| believe it will get done faster that 15 years.
| ncmncm wrote:
| Hasn't been, yet.
|
| The syllogism works the other way too.
| pdpi wrote:
| I always find it slightly amusing how there's remarkably few
| forms of power generation that don't eventually boil down to
| "use water/air/steam to make a turbine spin".
| infogulch wrote:
| Yep. Besides the common exception of photovoltaics, the
| only other method I'm aware of is "Direct energy
| conversion" which generates electricity by catching fast
| moving charged ions. But this only works with select fusion
| fuels / reactions such as protium-boron-11.
| rainbowzootsuit wrote:
| Thermoelectric generation in a RTG (radioisotope
| thermoelectric generator) on space probes like Voyager or
| Cassini are another.
|
| https://solarsystem.nasa.gov/missions/cassini/radioisotop
| e-t...
|
| You can also do hobby-level usage like charging a cell
| phone with a candle.
|
| https://www.instructables.com/Thermoelectric-USB-charger/
| cm2187 wrote:
| Turbines and piston engines also rely on the mechanical
| power of gas expanding.
| Projectiboga wrote:
| Here is B11+H fusion that generates electricity directly w
| charged particles emission.
| https://www.climateleadership.com.au/single-
| post/2020/02/21/...
| gridspy wrote:
| It is amusing. But it's just because that is the most
| efficient way we know to turn heat into electricity at
| scale.
| [deleted]
| Ekaros wrote:
| Also the range of scale is quite amazing. From single
| small wind turbine to massive ones to close 2GW...
| tuatoru wrote:
| Not as amazing as PV. From milliwatts (microwatts even,
| if you wannt) to Terawatts. And only stopping at
| Terawatts because we'd get bored going bigger.
| Ekaros wrote:
| Single Terawatt sized panels exist?
| JadeNB wrote:
| > It is amusing. But it's just because that is the most
| efficient way we know to turn heat into electricity at
| scale.
|
| Despite the 'but', I don't think you are disagreeing with
| your parent (who I took to be saying that they found it
| slightly amusing that we haven't discovered any more
| efficient ways to turn heat into electricity). If you
| meant that steam turning a turbine is the most efficient
| way _that we know_ to turn heat into electricity, then it
| seems that you 're saying the same thing as your parent,
| and it's not clear what 'just' adds. If you meant that
| it's the most efficient way _that exists_ , then, first,
| I wonder how you know; and, second, I think that far from
| this being 'just' anything, it's pretty remarkable that
| we stumbled on the literally most efficient possible way
| so early in our history of working with electricity!
| ncmncm wrote:
| If you read what he wrote, your question is answered
| already.
|
| Saying the best way we know is the best way we know is
| vacuous. Nothing about steam is especially good except
| that water is cheap. It was cheap before, and still is.
| Its problems are problems we have learned to live with.
|
| But it costs more than wind or solar, even with free
| heat. So it is a dead end.
| JadeNB wrote:
| > If you read what he wrote, your question is answered
| already.
|
| You are right; I missed "that we know". That is entirely
| my mistake. But then it seems to make gridspy's comment
| rather content-less.
|
| If someone says "I always find it slightly amusing how
| there's remarkably few forms of power generation that
| don't eventually boil down to "use water/air/steam to
| make a turbine spin".", then what does saying "it's just
| because that is the most efficient way we know"
| contribute? The 'because' suggests some justification,
| but it appears just to be re-stating what it's
| justifying. A re-statement can be valuable, but combining
| it with 'just' seems to be dismissing an observation that
| I, at least, found interesting enough not to dismiss,
| even if it is 'just' a description of existing facts.
| gridspy wrote:
| I find some merit in your argument. I feel like the GP
| said "We use lots of turbines, isn't that interesting"
| and I said "It's nice to see the common factor here is a
| translation of pressure -> electricity" or "temperature
| -> energy."
|
| So what I thought I was contributing here was an
| explanation of why we like steam and turbines so much.
|
| I'm pretty sure that steam, turbines, etc have a big
| efficiency loss. Like you guessed, I meant "the best way
| we know of to do it at industrial scale now."
| amelius wrote:
| And also because it is easy to turn most types of energy
| into heat.
| christophilus wrote:
| > boil down
|
| I see what you did there. I feel the same way, though. It
| feels primitive. But it's what we've got!
| robotresearcher wrote:
| If it ain't broke....
| dopidopHN wrote:
| Real question, not rethorical. Do we have any other way ? I
| can't think of any.
|
| Edit : solar don't involve having a Dynamo spinning.
| Retric wrote:
| The big ones are just PV or batteries, but there are a
| few more niche methods like thermocouples,
| piezoelectricity, or fuel cells.
| JadeNB wrote:
| > rethorical
|
| Since I can't imagine any easy way to have produced that
| as a typo, you may like to know that the spelling is
| actually 'rhetorical' (no accent in English, despite
| 'rhetorique' in French).
| amelius wrote:
| photovoltaics is entirely solid-state.
| addaon wrote:
| As are, more relevantly for nuclear discussions,
| betavoltaics.
| SnowHill9902 wrote:
| Cute comment but completely different type of decay.
| earthscienceman wrote:
| And very inefficient as a result, funny enough.
| dpierce9 wrote:
| I don't want to be rude but to say solar is 'inefficient'
| without qualification is essentially baseless ignorance
| or lying.
|
| PV/wind turbine efficiency and Rankine cycle efficiency
| are basically entirely different concepts physically and
| economically. Highly efficient rankine plants might turn
| 35% of the potential energy of expensive nuclear/coal
| fuel (which costs money) into electricity. In the process
| they produce waste heat and waste (dealing with those
| things is typically kicked down the road). Solar turns
| 20% of something that is free (being pointed at the sun
| modulo land use) into electricity with zero waste and
| zero additional waste heat. How is that inefficient (even
| if it were half that)? You can and should say lots of
| things about scale or nighttime but none of those have to
| do with prime mover efficiency.
|
| Now consider economic efficiency. The denominator of
| economic efficiency for solar/wind is financing charges
| and the numerator is multiplied by a lower capacity
| factor whereas for everything else the denominator is
| financing charges plus fuel costs. Fuel costs are
| expensive and boom/bust volatile creating huge economic
| uncertainties. These uncertainties increase financing
| charges further reducing economic efficiency. This is
| before you get to waste or waste heat.
|
| I don't think 100% solar is a realistic option but
| neither are baseless claims of inefficiency.
| jsjohnst wrote:
| > into electricity with zero waste
|
| > I don't mean to be rude, but to say this without
| qualification is essentially baseless ignorance or lying.
|
| Your own words can be used back at you.
|
| (Not agreeing with GP, but your zeal in rebuttal falls
| victim to your own accusation)
| ncmncm wrote:
| In kWh per dollar invested, solar panels are the most
| efficient generation technology ever fielded.
| addaon wrote:
| I'd have to think that any water mill over a couple
| hundred years old would give a circa 2000 solar panel a
| run for its money; they weren't particularly expensive,
| and amortization adds up.
| bacon_waffle wrote:
| It's not clear to me why the reference points need to be
| a couple hundred years ago, and a couple decades ago. Was
| the intent to point out that the dollars are a one-off,
| where the kWh's keep on coming as long as the equipment
| works?
|
| Even in my relatively wet and grey corner of the world,
| I'm confident that if I spent $X on PV vs hydro, the PV
| would produce more electricity and require less
| maintenance.
| ncmncm wrote:
| The amount of power your traditional water mill extracts
| would be exceeded by solar panels on its roof, which
| would be cheaper than the building under them, not even
| counting the cost of the water wheel and weir. The mill
| might last centuries, but only with continuous
| maintenance.
|
| A weir way uphill with a penstock and Pelton wheel could
| do better than the old mill, but both depend on landform
| features with limited distribution. If you needed twice
| the power, you would be stuck. But you can put out more
| panels.
| snovv_crash wrote:
| You can get multiband sonlar panels with efficiency in
| the low 40% range. This is similar to coal, nuclear etc.
| waynesonfire wrote:
| was curious about mirrors, which are used to boil water,
| "most concentrated solar power technologies will have an
| efficiency somewhere between 7 and 25 percent."
|
| "Though most commercial panels have efficiencies from 15%
| to 20%, researchers have developed PV cells with
| efficiencies approaching 50%."
|
| "Both nuclear and coal plants show a range of
| efficiencies. Nuclear plants currently being built have
| about 34-36% thermal efficiency, while one of the new
| reactor designs boasts 39%. In comparison, new coal-fired
| plants approach 40% and CCGT plants reach 60%."
| kadoban wrote:
| These comparisons seem basically meaningless though. What
| does it tell us that coal is "40%" vs solar being "20%"?
| Why does that number matter?
| tuatoru wrote:
| Coal is "40%", less the energy used in mining and
| transporting the coal, less the energy used in coping
| disposing of the ash and coping with the environmental
| and health harms arising from burning coal.
|
| For PV, a higher "efficiency" means less land is used for
| a given nameplate power output. Desert land is not in
| noticeably short supply, though.
|
| Or it might mean that PV is economically feasible in
| high-latitude or chronically cloudy areas.
| cush wrote:
| Aliens are looking down on us right now thinking, "we'll
| make contact as soon as they advance past the steam engine"
| dreamcompiler wrote:
| I like to think they're saying "We'll make contact when
| they realize they don't have to build a fusion reactor
| because there's already one in their sky."
| arlort wrote:
| It's interesting how you're assuming that a species which
| obviously has been navigating way past the point where
| any useful power can be extracted from their star would
| not see the utility of developing fusion power
| lagrange77 wrote:
| > past the point where any useful power can be extracted
| from their star
|
| I guess, if a species used a Dyson sphere for so long,
| they will certainly have colonized other solar systems,
| which each have their own star to milk.
| dreamcompiler wrote:
| I'm assuming that such a species would themselves have
| fully exploited the energy output of their local star(s)
| _before_ they embarked on building an artificial one. And
| that they would view any species trying this in reverse
| order as unintelligent.
| HereIGoAgain wrote:
| That's assuming a lot I think. Having the ability to
| create a large amount of power on demand is a lot more
| useful than it's popular to think these days.
| krsdcbl wrote:
| depending on the tech our hypothetical aliens employ, we
| might argue they solved hyperefficient power storage
| before fusion?
| sva_ wrote:
| Fusion sounds like hyper effective power
| storage/retrieval to me.
| concordDance wrote:
| Have you come up with some cheap form of electricity
| storage or are you advocating geosynchronous orbital
| solar?
| dreamcompiler wrote:
| I think the human race is about 100x closer to cheap
| electricity storage than we are to building a useful
| fusion plant.
| HereIGoAgain wrote:
| On a lower end medium time scale maybe.. but the kind of
| power we're talking about here and needed by society, is
| still a few discoveries and a few decades away from
| actually being, let alone being practical on a large
| scale. And the worst part is that only then does the
| discussion even begin about adopting, using and
| manufacturing/installing it at scale.
|
| Large scale HUGE capacity electricity storage is a LOT
| further away than a lot of people and interests are
| willing to... well.. as we see in europe.. allow for. We
| are going ahead with the first half of a system that
| isn't even complete in theory.
| mc32 wrote:
| If it were only that easy to keep them from invading
| earth!
| kidme5 wrote:
| If aliens have the capacity to interact with us, they've
| probably been doing it for a long time.
|
| We're their pet project, why would they invade?
| mc32 wrote:
| The cosmos is not startrek -one doesn't travel vast
| multigenerational distances in space and time to "just
| observe". If we could travel to an extra-solar habitable
| planet. Do you think we'd be like, huh, nice carbon based
| life, just like us. Awesome now let's go back "home".
|
| Or if we let off some earth mammals the beasts would be
| like, you know what, humans, take me and my descendants
| ten/a thousand generations down back to earth.
| evilduck wrote:
| This does make the assumption of aliens having similar
| lifespans. A life form that might live 500 or 10k years
| would view the personal cost of those distances much
| differently than humans, who view it as suicide.
|
| It also assumes similar moral and cognitive processes of
| what to do when encountering another planet's life,
| neither of which must hold true for a society or species
| to become spacefaring. Likewise, an alien's AI probe
| could be effectively immortal and that would drastically
| shape its opinions on a return trip.
|
| Or maybe they're intergalactic mayflies with innate
| knowledge for reaching orbit or relativistic speeds but
| they die each day and a new generation takes over
| tomorrow. All distances are suicide missions, even trips
| across their own planet. It would totally normalize
| multigenerational trips.
|
| I think it's short sighted to make any assumptions of
| human similarities when it comes to first contact.
| Cephalopods have independently developed significant
| intelligence in parallel here on Earth and they might as
| well be aliens to us despite a common evolutionary
| ancestor way back. A completely independent evolutionary
| path leading to intelligence could be incredibly counter
| to our expectations.
| mc32 wrote:
| We only know what we know. This is what we build off of.
| Also there are physics limits. We cannot go FTL and even
| getting to light speed would mean vast quantities of
| energy. Could there be new physics? We can't make
| decisions on something so far seems quite unlikely.
|
| Speaking of cephalopods, do they seem less aggressive
| than other species? Have they gone vegan?
|
| Is it more or less likely the species that goes vegan
| wins the race? And even if they did it would mean that
| they had to subdue a more aggressive species. In other
| words, pacifists cannot unilaterally (en)force peace.
| JadeNB wrote:
| > The cosmos is not startrek -one doesn't travel vast
| multigenerational distances in space and time to "just
| observe". If we could travel to an extra-solar habitable
| planet. Do you think we'd be like, huh, nice carbon based
| life, just like us. Awesome now let's go back "home".
|
| This sounds awfully knowledgeable about travel over
| multi-generational distances when neither you, nor I, nor
| any other human has ever done it. Maybe you're right that
| it's not what _we_ would do, but how can you, I, or any
| human _possibly_ know whether it 's what an alien species
| would do?
| mc32 wrote:
| Neither people, nor animals, nor plants travelled long
| distances to habitable places to then be satisfied and
| turn back. It doesn't happen on a continental scale so
| it's even much less likely to happen on an interstellar
| scale. If it's half habitable, you're gonna make that
| place a "home".
|
| It's a nice fantasy to think you can zip back to the home
| planet after prancing around the galaxy making
| discoveries and reporting consequential and timely
| information back home.
| tluyben2 wrote:
| Yep, and we are humans with a track record of breaking
| the prime directive everywhere we went on earth, so why
| not other worlds? If there is microbal life on mars, we
| _will_ kill it soonish.
| incongruity wrote:
| First - there's plenty of evidence of intercontinental
| trade prior to colonization/ migration in Humanity's
| past.
|
| Second, you have a very anthropomorphic perspective built
| in to your thinking. What if they had lifespans measured
| in centuries or longer? What if they had radically
| different views of life and death and generational
| cooperation? Alien life is, by definition, alien. It's
| hard to say what would/wouldn't be true.
| glenstein wrote:
| I find it bizarre that you would jump in here to caution
| about the limitations of our knowledge, and not jump in
| in response to the previous commenter who proposed that
| visitors would just be observing.
|
| If anything, this is the commenter that is being more
| careful not to entertain familiar science fiction
| presumptions and is exhibiting the discipline that you're
| asking for.
| Dylan16807 wrote:
| The previous commenter was being silly, in response to
| mc32 being silly, then mc32 switched to making a serious
| claim in response.
|
| > If anything, this is the commenter that is being more
| careful not to entertain familiar science fiction
| presumptions and is exhibiting the discipline that you're
| asking for.
|
| I really don't understand why you think this.
| checkyoursudo wrote:
| It's just a version of the Dark Forest problem. It is
| possibly much safer to drop an asteroid on any newfound
| civilization's head than to travel hundreds or thousands
| of years (at light speed) just to observe someone and try
| to figure out if they are going to drop an asteroid on
| your civilization's head first. IOW, the first-mover, the
| one who pulls the trigger first, the side that pushes the
| doomsday button first, etc ... the surprise attacker has
| a better chance of victory.
|
| (Good thing `Oumuamua missed. Better luck next time,
| chumps!)
| spaceman_2020 wrote:
| What if the alien civilization is so advanced that a jump
| across the cosmos takes about as much effort as driving a
| couple of miles down to the mall for us?
| mc32 wrote:
| The physics that would allow that does not exist.
| spaceman_2020 wrote:
| The physics that _we currently understand_ does not allow
| that.
|
| Our current model of physics is barely a few hundred
| years old. We're talking about a civilization that's
| potentially hundreds of thousands of years ahead of us.
| mc32 wrote:
| We're millions of years ahead of slugs never the less our
| advanced intelligence is incapable of changing physics. I
| doubt alien intelligence even if further advanced can
| change the nature of physics.
|
| Yes, there is a possibility we will learn more and there
| are other pathways, but at the moment, that is fantasy,
| so it would all be speculative.
| 7speter wrote:
| If thats the case they probably send drones every once in
| a while to see how things are progressing.
| incompatible wrote:
| We may not actually be all that interesting.
| tyingq wrote:
| They may not think of it as an invasion if they are
| exponentially more advanced than we are. Any more than I
| worry about bugs I might step on and kill walking across
| the lawn.
| mc32 wrote:
| It's irrelevant what they think. We care about us and our
| well-being.
|
| Invasion does not mean prejudiced extermination. If they
| ignored us as we might ignore insects when we discover
| new habitat then, yeah, I'd want to keep them from
| coming.
| zepolen wrote:
| What would you do if you can across an array of ants that
| were spelling out simple mathematical formula on the
| ground?
| tyingq wrote:
| I don't know that would be representative of the
| potential gap between us and them. We seem pretty far
| from faster-than-light travel or whatever other thing
| would allow them to visit.
| pmontra wrote:
| To clean the Petri dish? ;-)
| mrcartmeneses wrote:
| "Mostly harmless"
| spaceman_2020 wrote:
| Interestingly, the authenticity and legitimacy of UFO
| disclosures has been ramping up recently, right as we
| come closer to the cusp of fusion, AI and quantum
| computing breakthroughs. We've gone from stories in pulp
| magazines to reports in NYT and the Congress.
|
| Interesting times ahead
| mc32 wrote:
| Aliens may exist, but the phenomena people are reporting
| as UAP are not from aliens. There is money to be made by
| selling the idea of aliens and alien visitors to the
| public and to government (who go along with the idea
| because it can lead to more funding).
| incompatible wrote:
| These are the super-advanced aliens, that can travel all
| the way to Earth and secretly observe us, but
| accidentally come into the field of view of a random jet
| plane?
| Azrael3000 wrote:
| While I do not follow these discussions I'd argue that
| the advent of drones plays a major role in that.
| Additionally as long as our space tec remains as
| primitives we are quite boring as a civilisation
| pyinstallwoes wrote:
| Add self replicating nano material with competing biology
| to the mix! (Viruses). Self replicants for everyone&
| killingtime74 wrote:
| In a way hydro, solar and wind put us past this hurdle. I
| guess they're coming!
| cbozeman wrote:
| Hydro is just a steam engine at non-steam temperatures.
| johnchristopher wrote:
| Isn't hydro more like gravity ?
| snovv_crash wrote:
| Hydro just uses gravity to make the pressure for the
| turbine instead of heat + phase change.
| baq wrote:
| Yeah it's useful to have gravity on your side if your
| steam is liquid.
| computerfriend wrote:
| And wind is just a steam engine with less steam.
| ksaxena wrote:
| And Solar is just a steam engine with less steam, and
| less engine.
| eptcyka wrote:
| No, hydro is mostly solar - the water wouldn't be flowing
| downwards to the sea if it wasn't for weather caused by
| the sun.
|
| Solar isn't less steam and less engine, it's literally
| just solar, whereas everything else but geothermal and
| nuclear is solar with more steps. Natural gas and oil is
| just solar stored in paleo compost.
| cush wrote:
| If that's true than, then your body is mostly solar with
| a bit of food chain, therefore making your comment
| above... Also... Solar.....
|
| I need to go hug my wife and children
| eptcyka wrote:
| I don't disagree.
| [deleted]
| gricardo99 wrote:
| solar is the only one that doesn't spin a magnet next to
| copper wires
| kbar13 wrote:
| i could totally see solar simply being an array of
| mirrors to point sunlight at some water to heat it up so
| the steam turns a turbine
| Ekaros wrote:
| Also known as Solar thermal power plants. Which in cases
| of some implementations even have option for limited
| storage.
| js2 wrote:
| https://www.seia.org/initiatives/concentrating-solar-
| power
| [deleted]
| progre wrote:
| It could if we would let it.
| checkyoursudo wrote:
| There's nothing wrong with spinning magnets.
| JohnFen wrote:
| Yes, or as I like to think of it -- we're more of a steam-
| powered society now than we were during the "steam age".
| z3rgl1ng wrote:
| bryanlarsen wrote:
| It's also very expensive engineering. That's how a coal plant
| works, and the last coal plant that the US built cost $2B for
| a 600MW plant. Given how much cheaper solar & wind are,
| fusion will be dead in the water if it doesn't come up with a
| cheaper way of extracting energy from the reaction.
| tomatotomato37 wrote:
| Speaking of solar it would be nice if we could just plate
| the inside of a reactor with photoelectrics instead of
| blowing all the budget on a clusterfuck of a steam system.
| Too bad silicon doesn't like 100M degrees...
|
| Actually thinking about it figuring that out would make
| fission a lot more tenable too
| u320 wrote:
| Fusion produces neutrons, not photons.
| DFHippie wrote:
| I'm pretty sure it produces both.
| fy20 wrote:
| Is there an equivalent of the photoelectric effect for
| neutrons?
| ncmncm wrote:
| None. Hot neutrons are the lowest-grade sort of energy.
| blincoln wrote:
| Maybe a dumb question, but could one use bricks of
| depleted fission fuel as the neutron shield in a fusion
| reactor, and swap them back into a fission reactor every
| time they become fuel-grade again?
| ncmncm wrote:
| It would be an overwhelmingly smarter and better use of
| money to burn uranium in an ordinary fission plant, and
| maybe breed up extra fuel there.
|
| But we already know that fission, too, is uncompetitive,
| moreso each day as costs for renewables and storage
| continue relentlessly downward.
|
| Fusion has no chance of ever catching up.
| blincoln wrote:
| Sorry, maybe I was unclear. I wasn't asking about using
| the fusion reactor just to produce fission fuel. I was
| asking "if the fusion reactor produces a bunch of extra
| neutrons as a side effect, is this a way to use them to
| produce more energy later instead of throwing away that
| energy, or letting the neutrons actively damage the
| fusion reactor?"
|
| i.e. one needs to prevent the neutrons from escaping or
| degrading the material the reactor is made out of, so
| instead of just adding a throwaway shielding layer, would
| it work to use something that is not only super dense,
| but is currently a waste product[1], and also becomes
| more valuable in the process of being used as the shield?
| Seems like it would be vaguely equivalent to a
| photoelectric collector for neutrons, but I am not a
| physicist or reactor engineer.
|
| [1] I do think it's a shame that we stopped building
| breeder reactors, but that's a separate discussion.
| ncmncm wrote:
| Breeder reactors are not used because refining the bred
| fuel costs more than processing mined uranium.
|
| The overarching requirement on fusion neutron absorption
| material, besides delivery of heat to process steam, is
| that it needs to produce more tritium to burn. You don't
| get that if the neutrons are absorbed in something other
| than lithium.
| scarmig wrote:
| Fusion covers a lot of different types of processes, some
| of which release most of their energy in charged
| particles and photons.
|
| Though you'd need something very different from existing
| photovoltaics to capture the energy from those x-rays.
| ncmncm wrote:
| The fusion they are working on emits hot neutrons.
|
| It will never produce so much as one kWh of commercial
| power.
| MobiusHorizons wrote:
| Are you honestly suggesting that we place photovoltaics
| (which perform worse when they get hot, and can only
| absorb a narrow spectrum of the energy emitted by the
| reactor) inside a fusion reactor instead of using a very
| well understood and efficient heat -> electricity
| technology (steam)? I'm pretty certain they would just
| simply melt at the temperatures that a tokamak is
| subjected to, even if there weren't other issues with
| efficiency.
| lightedman wrote:
| This is nothing more than an engineering challenge,
| looking at it seriously.
|
| Cooling? an IR barrier in the reactor to stop IR from
| reaching the cells should solve about 80% of the issue -
| assuming you can make something transparent at the right
| wavelengths for the cells - and capable of withstanding
| the heat of the reactor. The other 20% is already doable
| with current technology, and we do it from large-scale
| solar farms to single-family homes - water tubing on the
| backs of the devices to a radiator or storage tank. Hell,
| while using them to harvest light energy, that water loop
| can be used to harvest heat energy, thus improving the
| overall system efficiency!
| flavius29663 wrote:
| solar and wind can be free, if the sun does not shine and
| wind is not blowing 100% of the time...
| ncmncm wrote:
| This trivial observation, always trotted out, is always
| meant just to distract. Trolling, really.
| flavius29663 wrote:
| It's not trolling, look at what Germany and California
| are struggling with...
|
| Also Texas, another state where they pushed green energy
| (wind) and slowed the investment in fossil fuels.
|
| We all want cleaner energy, but we must acknowledge that
| it is not easy.
| thomaslord wrote:
| Can you provide any sources on Texas having grid issues
| because of renewables? The biggest publicized issue I'm
| familiar with was caused by inadequate maintenance of
| fossil-fuel-based generation facilities - during that
| period of time renewables produced the expected amount of
| energy for the weather conditions. Of course that
| expected amount wasn't their peak output, but that's
| something you plan for if you're competently managing
| your grid.
| bryanlarsen wrote:
| On the contrary, California is struggling with with
| electricity generation during times of high A/C loads due
| to a heat wave. Those times correspond with high solar
| power generation, without solar they'd be doing a lot
| worse.
|
| On the contrary, Germany has met their goal of 80% full
| natgas storage several weeks early despite the French
| nuclear reactors being offline due to higher than
| expected renewable energy supplies.
| flavius29663 wrote:
| You're saying that Germany and California are not
| struggling with the electric grid...now I believe you're
| trolling
|
| They invested a lot in solar power, which is expensive,
| so they couldn't afford to invest enough in transmission
| and backup generators, and now they have expensive
| electricity and unreliable grids. Ignoring current year,
| I think Germany is second in the world in regards to
| expensive electricity (after Denmark) and California is
| one of the most expensive states in the US.
| nemo44x wrote:
| Solar and wind are not serious solutions to the energy
| needs of the planet today or in the future. As billions
| more people become part of a global middle class our energy
| requirements will expand dramatically from today.
| ceejayoz wrote:
| > As billions more people become part of a global middle
| class our energy requirements will expand dramatically
| from today.
|
| https://www.nrel.gov/docs/fy04osti/35097.pdf
|
| "In the United States, cities and residences cover about
| 140 million acres of land. We could supply every
| kilowatt-hour of our nation's current electricity
| requirements simply by applying PV to 7% of this area--on
| roofs, on parking lots, along highway walls, on the sides
| of buildings, and in other dual-use scenarios."
|
| "We would need only 10 million acres of land--or only
| 0.4% of the area of the United States--to supply all of
| our nation's electricity using PV."
| didericis wrote:
| 0.4% of the entire country is a massive amount of land.
|
| That's 10 million acres of wires, maintenance, habitat
| and all kinds of mischievous creatures, not least of
| which are humans. And it only works when the weather is
| good. And not all countries have the grid or engineering
| and maintenance capacity of the United States.
|
| It's not a realistic solution.
|
| By all means, lets put solar panels everywhere we already
| have buildings and roofs and power hookups and make a
| dent. Maybe at some point it'll be possible to use solar
| alone, and we can keep up the maintenance.
|
| Going all in on solar right now would be suicide. It'd be
| worse than the effects of anthropogenic warming. People
| are going to freeze to death this winter in Germany
| because they bought into the promise of renewables before
| it delivered and didn't diversify their energy supply.
|
| You should only phase something out when you can meet
| demands without it. Nuclear is a way to do that. Natural
| gas is a way to do that. Renewables are a way to do that.
| But you have to actually _exceed demand_ and have a solid
| diversified base before you panic switch because of
| climate change. Otherwise you kill and impoverish more
| people than climate change.
| ncmncm wrote:
| The argument from incredulity has rather a poor history.
| Are you sure you want to join in with all its previous
| failures?
| pfdietz wrote:
| I'm waiting for him to realize that agriculture will use
| two orders of magnitude more land than is needed to power
| the US with renewables. Will he conclude that eating is
| impossible?
| didericis wrote:
| One of the things I like about this site is the restraint
| (at least in comparison to other places) in substituting
| an argument this kind of snarky scoffing and engagement.
| It's brainless.
|
| Agriculture is already working, or was until its been
| starting to be shut down and curtailed due to alleged
| environmental issues like in the Netherlands. You can
| manage much larger chunks of land with plows and combines
| and other vehicles because of how you interact with the
| land when farming.
|
| You can't plant solar panels and have them just grow out
| of the ground and repair themselves and reproduce largely
| independently. It's a totally different type of land use.
| Managing solar farms is magnitudes more effort to build
| and maintain than agriculture.
| pfdietz wrote:
| Yes, solar and wind take money to build and operate.
|
| They require less money to build, and less to operate,
| than nuclear (per unit of energy output).
|
| So, your talking about land could only be a valid
| objection if land itself was the constraint. And that's
| what my snark about eating was aimed at.
| didericis wrote:
| Costs on paper, cost in reality over time, and cost due
| to physical and manpower constraints vs cost due to
| government subsidies and regulation are not equivalent.
|
| This claim that 10 million acres of solar panels is
| cheaper to build and maintain and actually put into use
| and store power from vs extremely high energy output
| nuclear plants with tiny footprints that can produce
| continuously reeks of extremely biased accounting.
| pfdietz wrote:
| We can look at actual costs in the real world to confirm
| what I just told you. This is not some conspiracy to
| defame your energy waifu.
| didericis wrote:
| The arrogance and presumption is the issue. I don't think
| it's a conspiracy at all. Frankly I don't trust people
| who aggressively point to models and facts and figures
| and don't actually engage with the WHY and the caveats
| and actually _think_ about the risk of non correspondence
| between the figures and the real world.
|
| That does not mean you're wrong, I simply don't trust
| your hand wavy dismissive argument about it being
| cheaper.
|
| If I see a report that looks at _the long term
| maintenance cost of an actually deployed modern solar
| farm_ , not hypothetical ones, and compares it to _an
| actually deployed modern nuclear reactor_ , I'll take
| that one.
|
| I have an affinity for whatever actually works, the main
| reason I think nuclear looks good is I trust basic
| physics and understand how much astronomically higher the
| energy density of nuclear power is in comparison to like
| everything else.
| ncmncm wrote:
| The economics of renewables are the simplest and most
| transparent ever seen in power generation.
| nprz wrote:
| Isn't the intermittency of the energy source the issue?
| And there's currently no scalable solution to efficiently
| store excess energy generated from solar panels?
| ceejayoz wrote:
| Sure, that's why no one proposes _only_ solar, nor do
| they propose solar in only _one_ place at a time.
| pfdietz wrote:
| It's rather amazing that you think that people haven't
| already thought of this issue and addressed it.
|
| In fact, it's long been addressed, and the cost of
| dealing with intermittency of renewable sources appears
| acceptable.
|
| https://ieeexplore.ieee.org/document/9837910
|
| > Even former critics must admit that adding e-fuels
| through PtX makes 100% RE possible at costs similar to
| fossil fuels. These critics are still questioning whether
| 100% RE is the cheapest solution but no longer claim it
| would be unfeasible or prohibitively expensive.
| ncmncm wrote:
| Intermittency means you need storage too. So, you build
| out storage too. The observation is vacuous.
|
| A renewable grid includes storage. Storage is cheap and
| getting cheaper.
| robertlagrant wrote:
| I really wish this sort of thing would either be better
| thought through or better articulated. 10 million acres
| is enormous. And is it continuous supply (if so, how?) Or
| just supply when it's sunny?
| ncmncm wrote:
| Isn't it amazing that no one has ever thought about these
| things before you dropped in?
| robertlagrant wrote:
| You've missed my point.
| ncmncm wrote:
| Everybody has known all along that renewables generation
| is intermittent. Mentioning it adds no light.
|
| And renewables happily coexist with other uses of the
| same land, so none is used up.
| robertlagrant wrote:
| > Everybody has known all along that renewables
| generation is intermittent
|
| That doesn't mean it's made clear in statistics. I've
| read plenty of people say "X generates as much as Y",
| where X is intermittent and Y is suitable for base load.
| Certainly enough to disagree that everyone knows it and
| is able to discern that from context-free statistics.
| ncmncm wrote:
| Literally every single person on Earth who even knows
| what renewables are knows they are intermittent. No one
| imagines solar panels produce peak power all the time, or
| any power at night.
| switchbak wrote:
| I think the truth is in the middle. Solar is becoming
| ridiculously cheap, but even if the panels were free
| there's still a lot of other costs to factor in.
|
| As explained elsewhere, a mix of energy sources is
| necessary.
|
| And your statement is devoid of context. Solar is already
| working well in North America (and elsewhere), and uptake
| will continue to increase. It won't be a panacea for the
| rest of the world, and solar+wind won't replace all other
| generation types.
| nemo44x wrote:
| Yes by all means deploy it but by no means is it a
| strategic solution.
| switchbak wrote:
| It's an important component of a strategic solution.
| Where it makes sense, aka: not in the artic circle.
|
| Not sure why you're dismissing it so out of hand. I agree
| it's not the panacea that many want it to be, but it's
| still very important, especially given its recent cost
| declines (solar specifically here).
| sdenton4 wrote:
| It's easy enough to solve... point an energy-collecting
| device at the giant pre-built fusion reactor in the sky.
| gridspy wrote:
| Yes, but most of the time that fusion reactor is behind a
| giant hunk of iron covered in various other matter. Even
| when in the sky, the sky itself is an effective insulator
| that only allows 1/4 of the energy through.
|
| That's why we are considering placing a converter above
| the sky to more efficiently pierce the sky with energy.
| pydry wrote:
| Or simply pumping water uphill.
|
| The UK is building two of these pump uphill things. Four
| more and it could sustain a 99% carbon free grid on solar
| and wind alone.
| ourlordcaffeine wrote:
| The UK already has 4 pumped storage plants
| pydry wrote:
| True, but existing plants are small in scale and arent
| really meant for large scale storing of solar and wind
| power like, say, Coire Glas.
| lightedman wrote:
| "Even when in the sky, the sky itself is an effective
| insulator that only allows 1/4 of the energy through"
|
| https://energyeducation.ca/encyclopedia/Solar_energy_to_t
| he_... Demonstrates otherwise. About 30% is lost to the
| atmosphere, 70% reaches the surface.
| gridspy wrote:
| Oh, I remember it being a much higher factor but I must
| be mistaken.
| markdown wrote:
| Towing the converter _outside_ the environment is
| something I can get behind.
| gridspy wrote:
| I always liked how NASA realised in 1970 that the moon is
| a sandpit of fusion-converter material. It's such an
| awesome reason to build houses above the sky.
| ncmncm wrote:
| It would take far more energy to extract the 3He from the
| moon's crust than you could get fusing it.
| gridspy wrote:
| The moon is high in silicon. You can make solar panels
| from mostly moon dust. Then build solar panels in orbit
| which are 4x the power generation of sea level panels and
| they experience less shading.
| ncmncm wrote:
| True enough. But by the time that could be fielded, our
| energy problems will already have been solved, or
| civilization will have collapsed.
| gridspy wrote:
| I agree with you relating to our existing energy
| problems. However I expect that humanity will be
| attempting to use as much energy as it can possibly
| create for at least the next 1,000 years.
|
| I hope we have a bright future growing into space,
| creating a Dyson ring, orbital habitats, etc.
|
| Replacing our current use of fossil fuels has plenty of
| strong ground-alternatives. I like the idea of Thorium
| salt reactors for base load, hydro stored energy and lots
| of local wind and solar.
| gridspy wrote:
| I support moving all the smoking buildings outside the
| environment also. Then many of them can use the fusion
| reactor directly, with the aid of mirrors and lenses.
| YoshiRulz wrote:
| I hear there's nothing out there but sea, birds, and
| fish. No environment in sight.
|
| (for the uninitiated: https://youtu.be/3m5qxZm_JqM)
| HereIGoAgain wrote:
| And cover half the land with panels and hope to god a
| hail storm or anything volcanic happens. Also learn to
| read in the dark for night times.
| u320 wrote:
| You cannot build a grid out of solar and wind alone.
| bryanlarsen wrote:
| A 100% renewable power grid is possible and inexpensive.
| Here's how to do it:
| https://mitpress.mit.edu/9780262545044/
| parkingrift wrote:
| Your source is a book??
| pfdietz wrote:
| What would you suggest he read instead? Sheep entrails?
| idiotsecant wrote:
| This is absolutely not true. My day job is designing
| control systems for renewable generation so I certainly
| don't have a bias against renewables - the opposite in
| fact.
|
| The fact remains that the physics of a grid powered only
| by distributed non-dispatchable wind and solar resources
| simply does.not.work. full stop without massive
| investments in storage and transmission upgrades. The
| physics isn't even debatable - it's simple. You only have
| to look at the very limited transmission infrastructure
| that currently exists and understand the simple fact that
| the power grid is a zero sum game. Power in = Power out
| or very bad things happen that lead to power out = 0.
| Zero sum generation + aging transmission = not enough
| power where you need it, when you need it if you get rid
| of traditional baseload sources.
|
| It's good to champion renewable generation, storage, and
| transmission upgrades. It's necessary infrastructure for
| the economic and actual health of our nation. It is _not_
| going to be inexpensive by any definition of the term. It
| 's going to be monumentally expensive even if it's
| completely necessary.
| ncmncm wrote:
| > _without massive investments in storage and
| transmission upgrades_
|
| So, we build storage and transmission. Storage cost is
| falling even faster than generation, and there are zero
| physics problems to be solved, just practical civil
| engineering.
|
| The cost of this much civil engineering will be very
| large, but much smaller than e.g. for that much nukes,
| and we will pay it, because the only other choice is
| global collapse when the degraded biosphere becomes
| unable to sustain our population.
| idiotsecant wrote:
| >So, we build storage and transmission.
|
| Oh is that all. How could nobody have thought of this
| yet?!?!
| ncmncm wrote:
| Strangely enough, people have thought of it. Just not
| you.
| brasic wrote:
| > Storage cost is falling even faster than generation,
|
| Citation please. The high demand for EVs and other
| battery-hungry devices has led to a situation where grid
| scale energy storage costs are currently increasing year
| over year and expected to continue doing so [1]. And
| pumped hydro storage is not something that will flexible
| enough for general deployment. > and
| there are zero physics problems to be solved, >
| just practical civil engineering.
|
| Alchemy is not a solved problem, and there is only so
| much lithium to go around.
|
| [1] https://cleanenergynews.ihsmarkit.com/research-
| analysis/grid...
| ncmncm wrote:
| Batteries are the most expensive storage. The
| overwhelming majority of storage will not be batteries.
| Of what is batteries, the overwhelming majority will not
| be lithium. Lithium batteries are well adapted for cars
| and phones. Other qualities are favored for utility
| storage.
|
| > _Alchemy is not a solved problem_
|
| Ah, trolling. OK.
| Dylan16807 wrote:
| What kind of storage is falling in price faster than
| batteries?
| ncmncm wrote:
| CAES, ammonia synthesis, hydrogen electrolysis...
|
| Everything comes down as manufacturing volume goes up.
| Dylan16807 wrote:
| Everything comes down, but it's hard to compete with >95%
| over 25 years.
| ncmncm wrote:
| Battery cost is not falling as fast as it was. The others
| have only just started down.
| brasic wrote:
| Making a substantive point using humor != trolling.
|
| What form of grid/utility energy storage do you expect
| will dominate in 20 years?
|
| I provided a reference to back up my assertion. Do you
| have any?
| adgjlsfhk1 wrote:
| a mix of hydro and non-lithium batteries. for grid scale
| batteries, you don't care about weight, and if you make
| it big enough can hear the battery if it helps. as such
| there are a lot of very cool battery technologies in
| various stages of commercialization that will never go in
| a phone, but make a lot of sense when you scale them up
| to a few thousand pounds.
| ourlordcaffeine wrote:
| >the overwhelming majority will not be lithium
|
| I'm seriously hoping that aluminium-chalcogen batteries
| [https://www.nature.com/articles/s41586-022-04983-9] can
| be scaled and commercialized soon
| davrosthedalek wrote:
| > Alchemy is not a solved problem, and there is only so
| much lithium to go around.
|
| We can make it -- in a fusion reactor :)
| Dylan16807 wrote:
| > The cost of this much civil engineering will be very
| large
|
| Remember they were replying to a claim that it would be
| "inexpensive"
| ncmncm wrote:
| The absolute cost of anything world-scale is unavoidably
| very large. Pretending serves no one.
|
| At issue is how _this_ cost compares to _that_.
| Renewables and storage costs, as big as they will be,
| will be overwhelmingly less than alternatives, and can be
| fielded faster.
| rcarr wrote:
| I honestly think this is one area which should be
| nationalised rather than left to the private sector. Yes,
| the investment will be massive, on the trillions scale.
| But:
|
| a) Once it's done, you're pretty much self sufficient
| energy wise. Sure, you may need the raw materials from
| other countries to make panels, turbines and batteries.
| But once you've achieved a 100% renewable clean energy
| grid, you're getting a fairly decent lifespan out of
| everything so you're not going to be as subjected to the
| whims of the market like most of Europe is experiencing
| with gas. The market should generally be more stable.
|
| b) Once your citizens have free energy, they have a
| massive chunk of disposable cash they were once spending
| energy. They will spend that or invest it: and both
| general spending and investing are taxed at higher rates
| than fuel spending (5% VAT on fuel spending in UK
| compared to 20% general VAT rate). Yes that is a massive
| loan for the government to put on the books, but they
| will probably get it back much quicker than expected.
| Dylan16807 wrote:
| If you give people a limited amount of free power that's
| equivalent to giving them some free money. Which is fine
| and dandy but it's rather unrelated to how the grid
| works.
|
| If you give people an unlimited amount of free power
| they're going to use it to mine cryptocurrency in a
| massively wasteful and expensive way.
| rcarr wrote:
| I didn't mean unlimited free power. I'd basically propose
| that the government would pay for as many solar panels as
| you can fit on your roof plus a battery in the garage or
| in a utility room. For apartments, the government would
| pay for some solar panels installed on a solar farm and
| you'd get a certain amount of energy for free covering
| the typical energy use of the size of your apartment. So
| we're mainly just covering normal domestic usage. Of
| course if you've got anything spare you're free to use
| that mining crypto but I don't think that's what the
| majority of households are really going to be doing.
| idiotsecant wrote:
| The surest way to make someone not value something is to
| give it to them for free. Giving away energy is a good
| way to make sure that we use as much energy as we
| produce, and then some. The key, I think, is to make
| energy usage painful, but make that pain proportional to
| your resources. A big power bill to a billionare and a
| big power bill to a single mom on food stamps should
| result in the same level of emotional distress to both -
| hopefully very little.
| rcarr wrote:
| Normally I would agree with you but not on this. There is
| a giant nuclear reactor in the sky giving out as much
| energy as we could ever possibly want. Literally all
| energy on this planet came from it: sunlight feeds the
| plants which are turned to oil or feed the animals which
| feed us.
|
| Once we have built the machinery to harness that energy,
| it does become pretty much free and we can use as much or
| as little of it as we like. The cost of maintaining the
| machinery will become ever cheaper due to the amount of
| power we can get for little to no effort. It becomes self
| sustaining.
|
| There are literally ongoing efforts right now to
| replicate Asimov's vision which was to create space based
| solar farms and transmitting the energy back down in
| radio waves to specific points. We could literally
| harness our entire planets energy use from just a few of
| these in strategic locations if it was done right:
|
| https://www.getsunsights.com/will-the-concept-of-space-
| solar...
| tomcam wrote:
| > Once it's done, you're pretty much self sufficient
| energy wise.
|
| What arm of the USA government do you trust most to get
| this job done efficiently and fairly? What do you think
| will happen when you use "more than your share" of
| electricity for a month or two and your (undoubtedly
| centrally controlled) account is deemed unacceptable? Or
| is it your thought that providing electricity free will
| reduce consumption?
| rcarr wrote:
| I'm in the UK so I don't know which branch of the US
| government I'd trust to get it done. What I do know, is
| that you guys have done some incredible things, look at
| your railways, roads, cities, subways, internet, space
| program. You have done massive scale programs in the past
| and I have no doubt that you could do it again in the
| future if the political will was there.
|
| As for the second part, privately owned houses would get
| as much energy as the solar panels and battery on their
| property can provide. Additional power would come from
| the grid and would have to be paid for as normal. For
| people in apartments, presumably you have records of
| normal energy usage for every house and apartment, you
| could use those to work out the amount of solar panels
| needed to add to a solar farm or the equivalent for wind.
| The government pays for the installation of that and the
| citizen gets the energy generated for free. Additional
| energy they use is then paid for out of their own pocket.
| HereIGoAgain wrote:
| Laughs in German!
|
| Seriously though. Maybe, if we solve the large capacity
| storage issues and are able to build a storage system to
| scale. So 3 or 4 decades if we are extremely lucky. But
| right now in reality....
|
| And it's still not clear if it would be enough in the
| end. We'd need cover everything in panels and put towers
| everywhere. The amount of resources needed for solar and
| wind is actually realistically insane at the scales
| needed. (one of the many problems usually ignored by
| wind/solar evangelism)
| zardo wrote:
| You also need transformers and batteries and power lines.
| ncmncm wrote:
| Most storage won't be batteries.
| salty_biscuits wrote:
| Then don't do it. Grids are expensive. Microgrids and
| storage seem like a winning plan.
| u320 wrote:
| Microgrids and storage cost way more than any method of
| generating power we are currently using. Please stop
| using buzzwords and look at the actual numbers.
| salty_biscuits wrote:
| I worked for years in a business providing support
| services for maintaining the distribution network to
| rural areas. The distribution network was run at a loss
| by the government. Please look at the numbers and stop
| reactively responding.
| ben_w wrote:
| At grid scale, batteries were about the same cost as a
| functionally equivalent fission reactor last time I
| looked (a few years ago). Despite which, batteries are
| one of the more expensive ways to store energy at scale.
| u320 wrote:
| I don't know where you looked then because batteries are
| not anywhere near low cost enough to be deployed at grid
| scale at the amounts required to run a grid of wind and
| solar. Even in a sunny climate with reliable solar
| output, if you assume that there is a 10% chance that in
| any year you will have a 10 day period of cloud cover and
| 50% lower solar output and your entire grid cost goes up
| by 5x! The math for storage is BRUTAL.
| ben_w wrote:
| Only 50%? That's a small enough reduction that the
| cheapest solution is double the PV.
| [deleted]
| adgjlsfhk1 wrote:
| you're ignoring how big grids can get. there has never
| been a day where the entire US was cloudy at the same
| time.
| snovv_crash wrote:
| But then you need to massively upgrade the transmission
| capabilities. There's no free lunch here.
| adgjlsfhk1 wrote:
| It's not a free lunch, but it's a lot cheaper than not
| doing anything about climate change.
| ben_w wrote:
| You _can_. It probably isn't a great idea due to global
| geopolitics, but the physics is sound and the price isn't
| unreasonable.
| chii wrote:
| Solar and wind _alone_ means no storage (otherwise, it's
| not _alone_!). This means you need to build at so very
| many locations as to have consistent power for baseload,
| and a transmission infrastructure to distribute across
| that location, that it becomes almost a global problem.
| Aka, a global grid spanning continents.
|
| Of course, this is actually desirable imho, but yes, both
| geopolitics as well as cost, stops this from happening.
| ncmncm wrote:
| Storage is not a source of energy. It is a way of
| managing an existing stock of energy. Grid, likewise.
|
| So, storage is just a part of the grid, and the grid may
| be fed by wind, solar, hydro, and geo "alone".
| snovv_crash wrote:
| Over a short timeframe storage can be a sink or a source
| of energy. The grid needs to be managed both over short
| and long timeframes - you can't just say "100MWh in =
| 100MWh out over the last 24h", it also needs to be
| balanced so that the input and output is constant on a
| per-millisecond basis.
| ncmncm wrote:
| That is what power system engineers are employed to get
| right.
| chii wrote:
| > Storage is not a source of energy.
|
| strictly speaking, sure. But it's a source for all
| intents and purposes, because in order to achieve the
| same outcomes using renewables as with fossil fuel
| powerplants, you'd need to pair it with storage. Or
| produce so much renewables, and be able to distribute it
| so widely, that no single location would lack power at
| any given time.
| sofan wrote:
| u320 wrote:
| Nobody has done it. Nobody has put forth a credible
| theoretical model on how to do it. If you believe
| otherwise please show how it can be done. With details.
| Things like frequency regulation, reactive power and all
| that stuff that makes the grid work. And include the
| economic calculations. The burden of proof is on you.
| ncmncm wrote:
| > _The burden of proof is on you._
|
| It is, in fact, not. And, you are no reliable judge of
| it. Your assessment will have exactly zero effect on how
| the transition to renewables plays out.
|
| Either we transition to renewables fast enough, or global
| civilization collapses first. Nobody can say which.
| pfdietz wrote:
| Lots of people have put forward credible models of how to
| do it. The key is to include power-to-X to provide
| dispatchable demand and a buffer for rare prolonged
| outages of the renewable sources.
|
| https://ieeexplore.ieee.org/document/9837910
|
| > Even former critics must admit that adding e-fuels
| through PtX makes 100% RE possible at costs similar to
| fossil fuels. These critics are still questioning whether
| 100% RE is the cheapest solution but no longer claim it
| would be unfeasible or prohibitively expensive.
| ben_w wrote:
| > Nobody has done it
|
| So?
|
| > Nobody has put forth a credible theoretical model on
| how to do it.
|
| HVDC global grid, mentioned loads of times on this forum.
| 60% antipodal loss with existing components that were
| optimised for much shorter connections, but even that
| loss is fine given how cheap optimally placed PV is. Cost
| about a trillion USD (ok) and a few decades of current
| global aluminium and copper production (meh), but that's
| still absolutely in the realm of the "we could afford it,
| shame about the politics".
| zetalyrae wrote:
| A few decades of how much of the world's aluminium and
| copper production?
| ben_w wrote:
| 100% for a few decades. Sorry, I thought was was
| implicit.
| [deleted]
| compumike wrote:
| I'm not sure where your numbers are from, but just because
| $2B sounds like a big number, it isn't inherently a
| dealbreaker.
|
| If that's 600 MWe, running at 80% capacity factor,
| amortized over 30 years, then the $2B becomes: 2e9/(600 *
| 1000 * 0.8 * 24 * 365 * 30) = $0.0158 / kWh -- the $2B
| capital cost amortizes to 1.6 cents per kWh of electricity
| sold. Not zero, but 1.6 cents is far less than the current
| market price of a kWh.
|
| If you're going to compare to utility-scale solar or wind,
| be sure to include their much lower capacity factor: https:
| //en.wikipedia.org/wiki/Capacity_factor#/media/File:US...
|
| (Admittedly: we don't yet know the capital cost of a
| working fusion heat source, or its capacity factor. Both
| will determine whether this is economically competitive.)
| dtgriscom wrote:
| You aren't including fuel costs; any guesses?
| compumike wrote:
| You might be interested in Lazard's "Levelized Cost Of
| Energy" PDF (https://www.lazard.com/media/451905/lazards-
| levelized-cost-o... , from
| https://www.lazard.com/perspective/levelized-cost-of-
| energy-...).
|
| On page 15 note "This analysis does not take into account
| potential social and environmental externalities or
| reliability-related considerations", and that solar and
| wind do not get the checkmark for "baseload" -- only
| "intermittent".
|
| Pages 13 and 14 show Fuel Costs as:
| Wind: 0 Solar: 0 Coal: $13-$18/MWh
| ($0.013 - $0.018 per kWh) Fission: $9/MWh ($0.009
| per kWh) Natural Gas: $21-34/MWh ($0.021 - $0.034
| per kWh)
|
| As a retail consumer, I'm paying about $0.15 per kWh,
| though I know that includes transmission and distribution
| and retail markup.
|
| Fusion has the potential to be very low on fuel costs.
| But the capital costs are an unknown. In my original
| comment, I tried to show that when amortized over enough
| kWh for sale, even $Billions in capital costs could make
| sense, if they give us a machine that produces zero-
| carbon baseload electrical generation at scale.
| pfdietz wrote:
| With fusion, you are basically burning the reactor. The
| actual fuel cost is inconsequential.
| legohead wrote:
| Assuming we can run an actual fusion reactor consistently,
| _how_ is the power taken out? I 've seen lots of comments
| about water/steam, but we're talking 100MdegC degrees here,
| that's insane! Do we bury this thing in the ocean?
|
| I'm being silly, but I'm genuinely curious if there are any
| plans, even speculative ones, on how to do this.
| DFHippie wrote:
| I haven't actually read the announcement, but I assume the
| tremendous temperature is in a tremendously small quantity
| of plasma. Basically, it's a few extremely fast nuclei.
| madelyn wrote:
| You warm up a piece of metal and pour water on it. The
| water keeps it cool and makes steam.
| vintermann wrote:
| Well, when it's that much heat, you're going to need a
| lot of water.
|
| Also, when dealing with that much high energy radiation,
| your metal has a tendency to wondrously become another
| metal, with all the problems that comes with.
| xani_ wrote:
| > Well, when it's that much heat, you're going to need a
| lot of water.
|
| we want a lot of water! That's a lot of energy!
|
| > Also, when dealing with that much high energy
| radiation, your metal has a tendency to wondrously become
| another metal, with all the problems that comes with.
|
| That's kinda problem with anything fusion or fission,
| wherever neutrons hit things get weird. Probably much
| worse for fusion tho.
| ncmncm wrote:
| It is moot: none will be built, because it would cost far,
| far more than other clean power sources already being built
| out.
|
| By the time this could be made to work, nobody will want it
| at any price.
| lake_vincent wrote:
| Yes, exactly! There are two problems here:
|
| 1. What's the most efficient way to boil water?
|
| 2. How do we generate electricity on a population scale
| without having to boil water?
|
| Question 1 is, apparently, much more tractable. We are still
| pretty much building the world's most sophisticated tea
| kettle.
| mrec wrote:
| As a Brit, I wholeheartedly approve.
| cameronh90 wrote:
| The power grid is just a way to remotely boil a kettle.
| Mvandenbergh wrote:
| Ironically all but one of our UK reactors are carbon
| dioxide cooled although to be fair that carbon dioxide is
| then used to boil water.
| throwaway0a5e wrote:
| >1. What's the most efficient way to boil water?
|
| Doesn't need to be the most efficient. Just more efficient
| per energy transferred to the water than all the other
| options.
| robbomacrae wrote:
| I don't follow. What you said seems to me the definition
| of the most efficient. Or at least.. it is what I assumed
| they meant.
| heavyset_go wrote:
| Most efficient can mean theoretically optimal efficiency
| or more efficient than other options. I think the OP was
| using the first definition.
| dbetteridge wrote:
| Local maximum vs global maximum
|
| Most efficient conpared to what we have already, but
| there may still be more efficient ways
| throwaway0a5e wrote:
| Doesn't matter if you waste half the energy if it's still
| a cheaper way to boil water than the next best thing.
| TaylorAlexander wrote:
| I think there is a zeroth problem here, which is how to get
| the heat from the plasma to the water. You have a fusion
| reactor making hot plasma that also needs to have water
| circulating in the right way. From what I gleaned from some
| fusion presentations the solution to this is itself an
| engineering challenge.
| pfdietz wrote:
| Indeed. As I mentioned upthread, the limits on power/area
| at the first wall of the reactor lead to DT fusion
| reactors having horrible volumetric power density. Their
| "figure of demerit" vs. fission is roughly (radius of
| plasma)/(radius of a fuel rod).
| Symmetry wrote:
| Fusion plants also need to absorb the neutrons coming out
| of the reactor and secure themselves a supply of tritium
| for their reaction. The most common solution is to do all
| three with a blanket of molten lithium that can absorb
| neutrons and heat from the reaction, transmute into
| tritium, and go through a heat exchanger with water to
| heat it up.
| ncmncm wrote:
| Molten lithium would interfere with your magnetic
| containment. You need a diamagnetic like LiH.
|
| Extracting tritium from a thousand tons of radioactivated
| lithium hydroxide at PPB concentration is left as an
| exercise for the ambitious reader.
|
| Good luck.
| ncmncm wrote:
| (Lithium hydride, not hydroxide.)
|
| Other neutron absorbers are contemplated, but extracting
| tritium from them on PPB concentration is no easier.
| willis936 wrote:
| Lithium fission also releases a nice bit of energy.
| robocat wrote:
| Lithium fission would be into Hydrogen and Helium -
| definitely not releasing energy. Do you mean that Lithium
| fusion with a proton or neutron releases energy?
| willis936 wrote:
| No I do mean fission. Li-6 fission releases 4.8 MeV. Li-7
| fission consumes 2.466 MeV.
|
| https://en.wikipedia.org/wiki/Tritium#Production
|
| There's a lot of lithium being mined for batteries. Just
| centrifuge out Li-6 or isolate it with some other clever
| means. Not much is needed for fusion fuel compared to
| industrial scale consumers of lithium and it's a healthy
| boost to heat output.
| compumike wrote:
| "Fusion Reactor First Wall Cooling"
| https://www.youtube.com/watch?v=bHJyoqDO0zw talks about
| the steady-state heat transfer out of a proposed tokamak
| design. Around 1:09:23 they show "1.5 GW" deposited as
| "0.3 GW from radiative photons -> surface heating" plus
| "1.2 GW from 14.1 MeV neutrons -> volumetric heating".
|
| Designing the first wall and the volumetric blanket are,
| indeed, engineering challenges.
| HPsquared wrote:
| 1.2 GW worth of neutrons is rather a lot. Neutrons cause
| damage to materials (e.g. disrupting the microstructure)
| and also make elements radioactive through neutron
| capture (activation products). It's a pretty complicated
| issue really.
| ncmncm wrote:
| Usually we spell that "intractable".
| DoreenMichele wrote:
| Sometimes people know enough to see things as merely
| _complicated._
|
| They usually can't adequately explain why in a single
| forum comment.
| ncmncm wrote:
| Generally somebody should have explained _somewhere_. But
| it is not considered very interesting, because nobody
| seiously expects to ever need to solve it.
| DoreenMichele wrote:
| Sometimes, it is explained _somewhere_ and it doesn 't
| matter, no one is listening.
|
| This topic is not one I'm personally familiar with, so
| possibly making an ass of myself, but (shrug).
| sien wrote:
| There are fusion companies that are trying to make
| aneutronic fusion work. This form of fusion doesn't involve
| boiling water.
|
| https://en.wikipedia.org/wiki/Aneutronic_fusion
|
| Helion Energy is the best known.
|
| https://en.wikipedia.org/wiki/Helion_Energy
|
| HB11 is another one
|
| https://hb11.energy/
| ncmncm wrote:
| Helion _might conceivably_ make something useful someday.
|
| The others will just spend investors' money until it
| dries up. Helion too, most likely.
| cbozeman wrote:
| Well if I'm going to throw money at a pointless
| endeavour, I could think of quite a few worse than this.
| ncmncm wrote:
| Pointlessness is.
|
| If you want to maximize pointlessness, Energy Vault is
| _right there_. But defrauding investors doesn 't seem
| like a great choice to enable.
|
| Maybe it would be better to do what might help avert
| global civilization collapse, thermonuclear war, and mass
| starvation?
|
| Investing in practical energy-storage tech factory build-
| out, solar farms co-sited on reservoirs and pastures,
| cost-effective hydrogen and ammonia synthesis tech are
| all overwhelmingly better uses, and can all be equally as
| cool.
| mandeepj wrote:
| > the heat is used to boil water which makes large turbines
| spin and produce energy
|
| I believe the containers would have to be really large.
|
| Also, if we have to continue boiling water at scale, we might
| reach water crisis some day. Although, it'd take very long
| time.
| mandeepj wrote:
| You can downvote with passion, but also let me know - what
| you find wrong. This is the single most thing that annoys
| me about HN.
| stevenhuang wrote:
| Look into the water cycle. Water doesn't just disappear.
| With sufficient means of energy generation the lack of
| _fresh_ water can be solved.
| Dylan16807 wrote:
| To put that into perspective, we need about a thousand
| gallons of water to produce a megawatt-hour of power. We
| can desalinate a thousand gallons of water out of the
| ocean by spending about ten kilowatt-hours. So that's a
| 1% energy overhead.
| ok_dad wrote:
| It's a fusion reactor, so how do you get the water into the
| part with the hot stuff? That's all inside a magnetic field,
| I think. Also, you have to consider the neutron radiation's
| effect on the pipes that carry the water into the core, it's
| going to activate several metals in there, and cause
| weakening of the pipe wall, which will necessitate
| inspections and replacements.
|
| It's a way harder engineering problem than you're letting on.
| Your comment is like a software user saying "How hard could
| it be just to add feature X?".
| pfdietz wrote:
| Exactly! Unlike in a fission reactor, where you can flow
| the coolant through the core, in a fusion reactor the
| energy has to be radiated through the surface of the
| reactor. The square/cube law comes into play: the surface
| area you can radiate through goes as r^2, while volume (and
| cost) of the reactor goes as r^3.
|
| This problem has been known for decades.
|
| http://orcutt.net/weblog/wp-content/uploads/2015/08/The-
| Trou...
|
| https://pure.mpg.de/rest/items/item_2131865_1/component/fil
| e... (see section 4.1.1)
| adgjlsfhk1 wrote:
| this only matters if there is a cap on radiation per area
| which there isn't.
| ncmncm wrote:
| There is if you want it not to crumble to tiny metal
| shards before it has paid back the cost of building it.
| johnbcoughlin wrote:
| The heat transfer is not (will not be) directly from the
| plasma to the water. The fusion neutrons will impact a
| "blanket", which is water-cooled, and kept at a temperature
| of around 600-800 C. Weakening of the pipes and all other
| structural components will primarily be from neutron
| irradiation. Not to say that any of it's easy, just not for
| the reasons you suppose. :)
| ncmncm wrote:
| It won't happen at all, because it would be
| astronomically expensive, way more than fission, and
| fission is already not competitive.
|
| So it is all castles in the sky.
| ok_dad wrote:
| Ah, cool! I wasn't sure how it would work, but it seems
| the hard part is the stuff leading to and including the
| "blanket? Thanks for clarification.
| Twirrim wrote:
| I was talking about this with the my kids (10, 7) the other
| day. Blew their minds a little that pretty much every power
| source comes back to the same central thing: moving magnets.
|
| Then I pointed out that our electric car does it in both
| directions too.
| gridspy wrote:
| Well, it's just another of our favorite converters -
| kinetic <-> electric energy.
|
| electric <-> kinetic - spinning magnets
|
| kinetic <-> pressure - turbine / pump
|
| pressure <- heat - boiler
|
| heat <- chemical potential - furnace
| kadoban wrote:
| The question is more how you get the heat to the water in a
| sensible way. It's _probably_ just engineering, but it's
| still something that needs to be worked out.
| tremon wrote:
| It's not my area, but I suspect that the heat extraction rate
| for a fusion reactor must be several orders higher than
| current fission reactors if we are to run them continuously.
| Fission reactions can be actively controlled by using
| reaction moderating material (control rods), which means we
| can tune the reactor activity to match the amount of heat
| extraction available.
|
| Fusion plasma must be sustained at a few million Kelvin or it
| shuts down again, and I'm not sure how finely we can control
| the operating temperature without either overheating the
| reactor or shutting down the plasma. I think it will take a
| lot more than dumb engineering to accomplish this.
| johnbcoughlin wrote:
| The heat flux management from the plasma is certainly not
| dumb engineering, true. However, the actual heat transfer
| technology is, I think it's fair to say, "dumb" compared to
| all of the plasma physics that has to enable the reactor in
| the first place. It's more or less just running cold water
| through the lithium blanket, which they hope to keep under
| around 1000 Celsius or so.
| ncmncm wrote:
| It is moot: it would cost far, far more than other power
| generation methods, so will never be built.
| pfdietz wrote:
| And the engineering here is very problematic. Indeed, the issue
| mentioned may be a showstopper for DT fusion.
|
| The problem is limits on power/area through the wall of the
| reactor. Because all the produced energy has to go through the
| wall, and because the area of the wall grows as r^2, the
| volumetric power density of a DT reactor (that doesn't exceed
| the power/area limit on the wall) must decline with increasing
| size.
|
| This leads to DT fusion reactors having horrible volumetric
| power density. ITER, for example, has a volumetric gross fusion
| power density of 0.05 MW/m^3. The 2014 ARC design, 0.5 MW/m^3.
| A PWR's reactor vessel? 20 MW/m^3.
|
| (If you look at the power density of the plasma alone, or the
| fission reactor core alone, you get similar wildly discrepant
| numbers: https://cpb-
| us-w2.wpmucdn.com/research.seas.ucla.edu/dist/d/... see slide
| 26)
|
| If you want to make heat to make steam to drive a turbine, a
| fission reactor will be much smaller, and much cheaper, than a
| DT fusion reactor.
| go_elmo wrote:
| Very wild idea: gaining electricity by induction instead heat
| since its charged matter.. but I know it doesnt make sense,
| as it only yields the kinetic energy which has too high
| entropy to be yieldable (no directed movement)..
| NegativeLatency wrote:
| A lot of the particles emitted are neutrons (which have no
| charge)
| jiggawatts wrote:
| An idle thought I had related to this is that the real trick
| to scaling up fusion power may be to _not_ try and extract
| the energy "through the walls", as you said.
|
| You know how they tell you to "visualise success" because you
| need to know what it _looks like_ to aim for it?
|
| Along those lines I was visualising what it would _look like_
| if someone like Elon Musk was on YouTube showing off some
| sort of future fusion reactor that 's "not just a piece of
| lab equipment", but something that would be dramatically
| better than any extant fission reactor or similar technology.
|
| I visualised it as an enormous stationary rocket engine,
| where cooling water was pumped through a relatively narrow
| (~50cm) "reactor tube". The water needs leave a hole in the
| middle for the fusion fuel gases. The hole is achieved by
| imparting a rotation to the water, so it "spins out" to the
| sides. Fusion would occur not throughout a large volume, but
| at a small number of "pinch points" along the axis set up
| using powerful magnets -- and not necessarily superconducting
| magnets! To get sufficient current through the coils, the
| charged exhaust is allowed to expand through a _magnetic_
| "rocket engine bell", producing moving (and accelerating)
| electric charges. This current is recirculated through the
| engine to provide the enormous magnetic field strengths
| required, via thick copper conductors aggressively cooled
| with water.
|
| Essentially it would be a magneto-hydrodynamic-fusion jet
| engine, using fields instead of impellers to achieve
| compression, expansion, and energy recovery to run the whole
| cycle.
|
| The bulk of the energy would be in the super-heated steam
| produced, which could be used as in traditional power plants,
| or used as a bone-fide rocket in space.
|
| Obviously there would be "challenges" to making this work, to
| put it mildly!
|
| But consider that with the kind of computer power we can
| throw at modelling physics these days, it may be possible to
| use "topology optimisation" style tricks to figure out the
| required geometry of the parts to achieve the conditions
| required for fusion while staying within material design
| constraints.
|
| If you ask me, a Manhattan-project style attempt at something
| like this would be a better way to "waste money" than yet
| another aircraft carrier, or whatever...
| alcover wrote:
| This greying-out voting system is unfortunate. It just
| impedes reading and looks bad. Please HN remove it already.
| pyinstallwoes wrote:
| I like the visualization. There's too many hyperrationalist
| over analytical minds here to appreciate it.
|
| Tesla could imagine his inventions and leave them running
| in his imagination and if they still worked a few weeks
| later he knew it would work in the real world. Allegedly
| anyway.
|
| Your visualization reminds me of some geometry I've seen
| and studied in ancient Vedic architecture/temples. There is
| this cavern with what looks like something is poured into
| in a cylindrical room, with holes in various places. The
| Egyptian story is also peculiar as some areas also
| complement this visualization. Especially the granite
| statue that was "never completed" and has a hole on its
| side next to a trench and is quite long vertically.
| Probably for water, but either way just reminded me of what
| you said. I personally think you're onto something with the
| pinch.
| randmeerkat wrote:
| > "You know how they tell you to "visualise success"
| because you need to know what it looks like to aim for it?
|
| Along those lines I was visualising what it would look like
| if someone like Elon Musk was on YouTube showing off some
| sort of future fusion reactor that's "not just a piece of
| lab equipment""
|
| The money went to his head, he's not the innovator he was,
| now he's just a billionaire that got bored with Mars and
| wants to own social media instead.
| wpietri wrote:
| I do wonder how much of an innovator he actually is on
| his own. He's known for his time at Paypal, but he was
| only there for 6 months, during which his big effort was
| to switch their Unix servers to Windows NT. He bought his
| way into Tesla.
|
| And speaking as somebody who used to work at Twitter in
| anti-abuse engineering, I can confidently say that he
| displays a very poor understanding of the problems he's
| in theory buying Twitter to solve. And that's before we
| even get to his terribly handled attempt to buy the
| company, which could literally cost him billions to get
| out of, or billions more if he's forced to buy and run
| the company.
| robocat wrote:
| Jim Keller talks about his impression working with Elon -
| skip to 1:20:50 of this (effing amazing) interview:
| https://m.youtube.com/watch?v=Nb2tebYAaOA
|
| Edit: Also Jim talks about Elon's engineering skills at
| 50 minutes into this interview:
| https://m.youtube.com/watch?v=1TmuJSbms9c
|
| Disclaimer: I'm not an Elon fan at all.
| RaiausderDose wrote:
| thx, this interview seems great. Jim is a cool dude.
| xani_ wrote:
| Wasn't he fired from paypal for incompetence and got
| millions basically "coz he was there early and got the
| stock" ?
| wpietri wrote:
| Yes, he was definitely fired after a short stint. Stories
| on why don't totally line up for me, but incompetence is
| one of the explanations, and I feel like it's pretty hard
| to get fired from a CEO spot that quickly.
| philwelch wrote:
| He bought his way into Tesla very early on, oversaw the
| design of the first Roadster, and took over as CEO before
| the first Roadster launched. He's also been at SpaceX
| from the start and has apparently been involved at a
| technical level from the start.
| wpietri wrote:
| I've had some bosses/clients that were "involved at a
| technical level". Let's just say that their being
| "involved" in a successful project is not a perfect
| indicator that they are particularly skilled innovators.
|
| For example, consider Steve Jobs. He was hugely involved,
| but not particularly technical. He was very strong at
| marketing, and also very strong at understanding certain
| kinds of user need and then berating people until he got
| something that met his high standards.
| ncmncm wrote:
| Correct: he is not.
|
| All the success he has had comes from lots of bucks to
| start from, and lucky hires. You can tell from all his
| obvious duds, and the idiotic things he says whenever he
| goes off-script.
|
| Gwynne Shotwell probably deserves the credit for SpaceX,
| and probably all of that for her personnel actions.
| dotnet00 wrote:
| And yet every biography and early employee of SpaceX will
| say otherwise about Musk's importance to the success of
| the company. Shotwell however does not get enough credit
| in the eye of the general public (she's quite popular
| among people who keep up with SpaceX), Musk has always
| emphasized how important she was/is for securing
| contracts for them and keeping engineering from going too
| wild.
|
| Like when Musk wanted to cancel Falcon Heavy because it
| was turning out to be much more challenging than
| expected, was a dead end in terms of Mars ambitions and
| Falcon 9 had improved enough that it basically took most
| of the launches FH had been intended for, but she pushed
| for them to work on it anyway because IIRC they had
| enough potential customers lined up to go forward with
| it.
| wpietri wrote:
| Two quibbles:
|
| One, saying that he was important to the success of the
| company is not the same thing as saying he's a
| particularly good technical innovator on his own. Take
| Steve Jobs as an example: important to the success of the
| Mac, but as a visionary who was also enough of an asshole
| that he got fired.
|
| Two, what people will say about an egotistical, litigious
| billionaire is limited. Even more so when he controls
| their income and/or they still hold a lot of illiquid
| stock. Note, for example, that Musk fired 5 people just
| for internal criticism:
| https://www.reuters.com/technology/spacex-fires-
| employees-in...
|
| I saw a lot more negative accounts about Steve Jobs
| starting a few years after his death than I did in the
| years leading up to it. I expect to see something similar
| with Musk.
| nickserv wrote:
| As someone having hired quite a few people over the
| years, I can say without a doubt that there are no lucky
| hires.
|
| If you know how to hire well, and have tons of money,
| it's difficult to do badly.
| ncmncm wrote:
| Don't dislocate anything patting yourself on the back.
|
| Overwhelmingly more of success is luck than anybody
| involved likes to think.
| pyinstallwoes wrote:
| Oh yeah totally? Just luck! Wow, what a lucky man right?
| Probabilistically nearly impossible but hey?
| Statistically it's still possible as a fluke. Super
| rational thinking that's applicable to increasingly well
| understood mental modes of reality. Bravo!
| sudosysgen wrote:
| Probabilistically it's not that implausible. Musk has
| what, one successful company he founded himself - SpaceX?
| The hyperloop is flop, the boring company is a flop too,
| so is SolarCity, and the sucessful one came with a lot of
| exceptionally great hires. I'd say empirically his skill
| at hiring competent people that are willing to work hard
| is higher than average, while his engineering skills
| don't seem to be particularly special.
|
| 1 out of 4 seems solidly probable to me.
| wpietri wrote:
| Yeah, many people don't get how much the world is tilted
| in favor of the rich. Look at Jared Kushner's ability to
| keep failing upwards, for example.
|
| Musk is an amazing hype man; the way he talked Tesla's
| stock price into the stratosphere gave him incredibly
| cheap capital. And he was correct in thinking that
| electric cars were a coming thing that the major auto
| companies were sleeping on, so he gets points for
| insight. But now that the majors are in the game, over
| the next decade we'll see how much Tesla's built on skill
| vs luck.
| randmeerkat wrote:
| > I'd say empirically his skill at hiring competent
| people that are willing to work hard is higher than
| average...
|
| He wasn't competent at hiring the right people, his ideas
| in the beginning looked amazing and drove the best minds
| to apply there. Now they're leaving...
| baq wrote:
| Gwynne absolutely is the unsung hero. (Though in truth I
| think more spacex fans know about her importance than it
| would seem. Not sure about the outside world.)
| xani_ wrote:
| Could the part of the plasma be diverted into heat exchanger
| and back into the stream somehow ? I guess problem there
| would be having one that doesn't just melt away. Maybe
| shoving water into it so it flash-evaporate and we're back to
| the ye olde steam?
| melony wrote:
| Back to stellarators? Mobius strips are very beautiful.
| qikInNdOutReply wrote:
| Stellarators do not solve the problem, they would heat
| evenly too. (TRIZ drums) What is needed is some sort of
| "abblative" migrating system, that leaves behind its heat
| to harvest, while the fusion process travels onwards,
| stressing other rejuvinated parts of the containement
| vessel. Basically, a series of reactors, pumping the plasma
| in circles once ignited.
|
| Or we dump the whole idea, call it a day and pump all the
| money into musks larange solar power plant. Which
| ironically is a fusion containement in the distance power
| scheme. Which then will have problem with solar winds.
| Funny how the small plant mirrors the problems of the
| larger soon to be plant.
| IX-103 wrote:
| What's wrong with pulling the energy from the magnetic
| containment system?
|
| We already are using the magnetic containment system to
| redirect charged particles in the plasma back into the
| plasma. If we do so less forcefully than they were heading
| out, but still enough to stop them from leaving, we can
| convert particle velocity directly into electricity (AC with
| a relatively linearly decreasing frequency distribution, I
| think). This also has the effect of cooling the plasma (since
| temperature is related to average particle velocity).
|
| The challenges I see here are: 1) The faster the control
| system, the more efficient it is at extracting energy -- it
| can extract the energy of higher frequency components. 2) You
| may need a very large magnetic field (larger than needed for
| containment) to make this practical 3) Coil geometry and
| efficiency becomes critical.
| pfdietz wrote:
| 80% of the fusion energy from DT fusion comes out in fast
| neutrons, which ignore magnetic fields.
|
| The other 20% has to come out _somewhere_. If it could be
| converted to electrical energy maybe it could avoid
| surfaces (Helion plans to do this, with DD + D3He) but when
| it 's just 20% of the output that doesn't buy you much.
| vintermann wrote:
| I knew neutrons was a headache with nuclear energy in
| general, but I didn't know it was that bad.
|
| I would not be excited about attacking the problem of how
| to safely get energy out of a soup of hot, corrosive,
| exotic radionuclides.
| pfdietz wrote:
| And DT fusion neutrons are even worse than fission
| neutrons, since they are much more energetic (and because
| only 3% of the energy in a fission reactor is released in
| neutrons.) The 14 MeV DT neutrons are above the threshold
| for (n,p) and (n,alpha) reactions, which cause gas to
| accumulate in reactor materials. The helium produced by
| (n,alpha) reactions accumulates in tiny bubbles that
| would reach extreme pressures and rip materials apart.
| jjk166 wrote:
| And neutrons pass straight through solid matter, dumping
| their energy volumetrically, completely solving the
| surface area scaling problem.
| dahfizz wrote:
| Taking your number of 0.05 MW/m^3, Back of the napkin
| calculation is that the USA would need ~8,000 gigafacory-
| sized reactors to meet 100% of electricity demand.
| wiz21c wrote:
| Euh ? In a few paragraph you basically say that even if
| fusion works, getting energy out of it will be almost
| impossible in a meaningful way (you're showing order of
| magnitudes of difference). But, don't the engineers at ITER
| and other facilities have already though about that ? It'd be
| very irresponsible to start such a project knowing in the
| beginning that, at the end, there's a high chance of
| failure...
| pfdietz wrote:
| That's a good question. Why _do_ fusion people not pay
| attention to this issue?
|
| The answer is some do. And those people tend to get
| frustrated and quit the field (or, if they are lucky,
| notice the problem early and never go into fusion at all.)
| Lidsky is a famous example; Pfirsch and Schmitter in Europe
| are others. Others bottle up their objections and only let
| them out as they retire.
|
| The more common coping mechanism is just to assume someone
| else is going to solve it and not pay too much attention
| while working on other issues. It helps to focus on physics
| issues -- which are very interesting, after all -- and tell
| yourself that this problem is "just engineering" and can't
| be too hard to solve, in comparison, and that anyway
| telling yourself it's bad to think about it before the
| physics is nailed down (which is wrong, but lets you stop
| worrying that you've wasted your career.)
|
| As for ITER specifically: ITER is costing > $20B for
| something that could produce maybe 400 MW gross fusion
| power (and isn't engineered to produce tritium, electrical
| power, or to survive more that a few weeks at full power).
| Industrial levels of denial are needed to tell oneself
| something like that is on a trajectory to relevance.
|
| Perhaps an even better question is: why are people funding
| DT fusion? For governments, I think it's because in many
| cases the purpose of government research funding isn't to
| solve problems, it's to be seen working toward solutions in
| the distant future (and that perception can be achieved
| even if there is no actual chance of success, if the public
| is sufficiently unaware, which it is.) For venture capital
| I'm not clear what the explanation is. Spinoff technologies
| like high Tc superconducting magnets, maybe?
| marcus_holmes wrote:
| And yet history has usually proven them right to have
| this kind of attitude. The first instance of _everything_
| is ludicrously expensive and commercially non-viable as
| it is. Then it gets cheaper and easier and eventually
| commonplace and boring.
|
| It's often the case that the commercial applications for
| a technology are not apparent to the researchers doing
| the research. They're focusing on the science/engineering
| challenges. Later, sometimes much later, it becomes part
| of an economically-viable product or service.
| pfdietz wrote:
| This is survivor bias showing its face.
|
| Sure, for successful technologies, naysayers were wrong.
| But almost all technologies (sufficiently finely defined)
| fail. The naysayers are usually right.
| eternalban wrote:
| Given the massive payoff to humanity if this technology
| comes on line, it is perfectly reasonable to have this
| attitude.
| xani_ wrote:
| It's an experimental reactor. The whole point of it is to
| figure out the issues before making production reactors
|
| Just like it was for experimental reactors for fission.
|
| Sure it _might_ be unfeasible but you gotta give it a try
| before judging it a failure
| Zoadian wrote:
| compare it to the space program. that didn't really have
| any directly useable goal. but the technology produced in
| the process is used everywhere. DT fusion may or may not
| work. maybe the problems may get solved some day, maybe
| not. we'll never know if we don't try. and the technology
| we get in the process is valueable regardless.
| pfdietz wrote:
| Spinoff technologies from space are another "sell the
| perception" thing. There's a lot of BS there. But as long
| as the public swallows it, it works to justify the
| program.
| HereIGoAgain wrote:
| Even if you choose to ignore all that has come from it..
| Space is quite possibly the most important thing we can
| be investing time, money and research into in terms of
| future advancement and sustainability of the human race.
| HereIGoAgain wrote:
| No, it's just saying they we haven't really done the
| serious work and engineering yet required to have an answer
| for this yet. Remember, we still aren't even sure which
| type of reactor design will work/be used. These are the
| type of problems that we can't seriously deal with until we
| have at least the basics down.
| cma wrote:
| Can the wall be baffled like an air filter to increase area?
| I get that the flux through it in total at a given radius
| would be the same, but is the heat being pulled out through
| plumbing or something?
| dotancohen wrote:
| That only works to increase the surface area in materials
| with poor heat conduction, such as an aluminium-air
| interface on an air-cooled motor (air is a poor conductor
| of heat). Poor heat conduction is not the problem here.
| pfdietz wrote:
| Actually, heat conduction is something of a problem here
| in at least one way.
|
| Some of the energy going to the first wall impinges on
| the surface of the first wall and becomes heat there
| (photons from the plasma, direct impact of charged
| particles from the plasma on the surface). This must be
| conducted through a vacuum-tight barrier layer before
| reaching a coolant channel. The ability of this layer to
| dissipate heat (before stress from differential thermal
| expansion of the inner hot/outer cold parts cause it to
| fail) is proportional to its thermal conductivity.
|
| For ITER, the relevant layer of the first wall armor is a
| CuCrZr alloy. However, this alloy is unsuitable for use
| in a production DT reactor due to activation. For DEMO,
| this layer is going to have to be made of RAFM steel,
| which has an order of magnitude lower thermal
| conductivity.
|
| This problem MIGHT be solvable with a liquid first wall
| (flowing liquid lithium), but it's not clear all the
| penetrations of a fusion reactor can be shielded in that
| way -- and any that are not will face this issue. And the
| lithium doesn't solve the neutron wall limit problem
| unless its very thick.
| ncmncm wrote:
| As you have noted elsewhere, molten lithium would
| interfere with magnetic containment. Lithium hydride
| melts at a rather higher temperature. I don't know how
| reactive molten LiH would be with pipes. I know letting
| any air into contact with molten LiH would be, as we say,
| bad.
| Mvandenbergh wrote:
| On the other hand, basically every complicated bit of
| engineering on the PWR is due to the fact that it does have
| such a high volumetric power density. A PWR is basically a
| fancy (very fancy) pressure vessel which is cheap (in
| relative terms) and then parallel redundant cooling systems
| and containment buildings because dealing with such high
| power density is hard. Right after shutdown, the power
| density from decay heat is still 1.3MW/m3 and dealing with
| that decay heat in all currently conceived circumstances is
| where all the money goes.
| pfdietz wrote:
| So, why do fission reactors go with high volumetric power
| density, then? Because they'd be even more expensive if
| they didn't.
| tlb wrote:
| The uranium has to be in a small volume for the chain
| reaction to work.
| pfdietz wrote:
| That doesn't mean the power density has to be high.
| tlb wrote:
| It has to be high within the core. I suppose you could
| add some empty space nearby
| pfdietz wrote:
| No, it does not have to be high within the core. A
| reactor can be operated at a low power level. This is not
| like a fire that goes out if the flame is too weak.
| tlb wrote:
| The problem with that is that cores are very expensive.
| They require 100s of kgs of enriched uranium. If you run
| them at half power, you need twice as many and your cost
| goes up dramatically.
| pfdietz wrote:
| The uranium lasts twice as long, though. So aside from
| interest costs it's a wash, at least for fuel costs.
|
| You are right that the reactor structure costs more.
| Which is the point I've been trying to make.
| Mvandenbergh wrote:
| Essentially. The CO2 cooled AGR has much lower power
| density and was thought by its designers to be a much
| superior design to water cooling for safety and cost
| reasons.
|
| It turns out, definitely not on cost grounds and the AGRs
| are all reaching technical end of life a few years after
| their original rated lives whereas light water reactors
| are getting life extensions basically everywhere for
| decades beyond that.
|
| Light water thermal reactors are the worst kind of
| nuclear reactor except for all the other ones which have
| been built.
| trhway wrote:
| Yes, the Sun has volumetric intensity of a compost pile.
| api wrote:
| The sun's _core_ where most fusion happens would be the
| appropriate comparison. The rest of it is a boiling blob
| heated by the core.
| diordiderot wrote:
| Can you explain this like I'm a 5 year old?
| jjk166 wrote:
| The overwhelming majority of the sun is made up of
| hydrogen, and specifically the isotope protium, which is
| just a proton with no neutrons.
|
| When two protons collide, the overwhelming majority of
| the time they just bounce off eachother. The diproton (a
| particle with two protons and no neutrons) isn't just
| unstable, it's basically forbidden.
|
| However there is an incredibly rare chance that when two
| protons come together instead of just splitting up, one
| of the protons will turn into a neutron, thus producing
| deuterium, the hydrogen isotope with one proton and one
| neutron. Deuterium is much more capable of fusing.
|
| Now when I say incredibly rare, I mean like "unlikely to
| happen to any given hydrogen atom over the lifetime of a
| star" rare. Luckily stars are big, and dense, and thus
| contain a lot of hydrogen atoms hitting each other very
| frequently. Thus you have a slow but consistent burn of
| hydrogen over billions of years. Once it's converted to
| deuterium, it fuses within about 1 second. This produces
| helium-3 (2 protons, 1 neutron), which is also capable of
| fusion, but not with the abundant protium[1], so it takes
| some time to find something to fuse with. A helium-3 will
| on average survive about 200 years before it fuses, which
| is still pretty short as far as the sun is concerned.
|
| This slow burn means that within any given chunk of the
| sun there aren't that many fusion events occurring. Even
| in the deepest core of the sun, power densities never
| exceed 275 Watts per cubic meter. By comparison, compost
| releases about 7000 Watts per cubic meter at its peak
| decay rate and even over longer time periods averages
| around 600 Watts per cubic meter. Human metabolism
| releases about 1600 Watts per cubic meter. But since the
| sun is so immensely large, it has a lot of cubic meters
| of fusing hydrogen. Overall, it's producing 3.8x10^26
| Watts.
|
| [1] Actually helium-3 can (at least in theory) fuse with
| a proton, it's just extremely rare. In fact it is so rare
| we've never actually observed it.
| adrianN wrote:
| For entirely different reasons though.
| trhway wrote:
| I see there the same relationship. If you have a fixed
| surface temperature then you have to decrease volumetric
| intensity when increasing volume (the ITER and further
| case). If you have a fixed volumetric intensity then
| increasing volume results in higher energy flux per unit
| of surface and thus results in surface temperature
| increase to increase the intensity (T^4) of radiation
| away of that energy - that is the Sun case.
| ricksunny wrote:
| I like this term 'volumetric intensity'. I don't know how
| common the term is, (some cursory googling just turned up
| one fusion paper from the 1990's)) but it would make
| appreciating Gauss's Law in E+M much easier from the
| outset than the typical surface integral calculus
| typically used to introduce the subject.
| concordDance wrote:
| I'm confused about how 50kw/m^3 is "horrible". A 4m a side
| sphere would give 1.5mw, which is a decent sized plant.
|
| What's wrong with a 3-6m size reactor vessel?
| danw1979 wrote:
| 1.5 Mega Watts (for the avoidance of doubt) is about a
| tenth of the output of a single modern wind turbine at full
| tilt. It's not a lot of power.
| pfdietz wrote:
| And this is _thermal_ power, so divide by 3 to get
| electrical power.
| HereIGoAgain wrote:
| But how much is it when the winds not blowing,... or
| blowing too hard?
| jjk166 wrote:
| Well that wind turbine is quite a bit bigger than 4
| meters. 4 meters is the size of a car, and 1.5 megawatts
| is enough power for about 600-1500 homes.
| pfdietz wrote:
| The cost of the reactor vessel is directly related to how
| large it is (and how complex). The larger object uses more
| material, has more parts, has more joints between parts.
| Its reliability decreases along with its size, increasing
| cost even more (as all those parts and joints must now
| themselves have lower failure rates to maintain a given
| system failure rate.)
| throwaway0a5e wrote:
| This is an incredibly naive bordering on "probably just
| dishonesty masquerading as ignorance" thing to say.
|
| Of course cost goes up fairly linearly with size. More
| rebar, more pipes, more materials, more diesel in the
| bulldozer, more man hours, more welding rods, more welds
| to inspect, more money.
|
| But there are also a ton of one per instance overhead
| paper pushing costs, especially with something as
| onerously regulated as nuclear that are a large fraction
| of overall costs and will be roughly the same whether
| you're building a 1kw facility or a 1gw facility. All of
| that has to be amortized over your reactor. So if you
| build a small reactor each dollar of reactor might have
| $10 of overhead it needs to amortize. If you build a big
| one each dollar of reactor might only have another $1 it
| needs to amortize.
|
| Of course there's a sweet spot before the reactor is so
| massive the part count grows so high that the MBTF starts
| getting you. That sweet spot also has a low end below
| which the fixed regulatory and palm greasing costs are so
| high that your tiny reactor can never hope to pay them
| back in it's lifetime.
| pfdietz wrote:
| The argument being made doesn't require a linear
| relationship between size and cost. Remember, we're
| looking at two objects with the SAME power output, one
| much larger than the other.
|
| The MTBF/MTTR of fusion is actually looking like an
| extremely serious problem. Fission reactors can operate
| with 2% of their fuel rods leaking. A single leak through
| the vacuum boundary of a fusion reactor will contaminate
| the plasma and shut things down. And repairs on a fusion
| reactor are going to be _much_ more difficult than simply
| replacing fuel rods. The innards of any fusion reactor
| will be so radioactive that hands-on maintenance will be
| impossible.
| pyinstallwoes wrote:
| Thermoelectric generator. Take the differential and output a
| voltage?
|
| Why hasn't this been done? Why do we go to the steam stage when
| we could just exploit the termoelectric properties of
| temperature and current?
|
| 1. Thermoelectric generator:
| https://en.wikipedia.org/wiki/Thermoelectric_generator
|
| 2. Thermocouple https://en.wikipedia.org/wiki/Thermocouple
|
| 3. https://en.wikipedia.org/wiki/Thermoelectric_effect
| snaily wrote:
| > The typical efficiency of TEGs is around 5-8%
|
| A steam turbine is many times more efficient.
| pyinstallwoes wrote:
| But it has way more parts... And it moves. This other path
| has no moving parts.
| fsniper wrote:
| I still don't understand why we don't really have a reliable
| and good way to convert chemical bond/radioactive energy into
| electrical energy directly? Why do we still require 2
| conversions of Chemical -> Heat -> Electrical ?
|
| Is that something that is impossible or not cracked yet?
| tullianus wrote:
| Some examples exist for directly converting alpha, beta, and
| gamma particles into electricity, but I didn't find anything
| for neutrons in my brief search.
|
| https://en.wikipedia.org/wiki/Atomic_battery#Radiovoltaic_co.
| ..
|
| https://en.wikipedia.org/wiki/Betavoltaic_device
| ngcc_hk wrote:
| Bomb vs power plant ... explosion is quick heat in a sense.
| bumblebritches5 wrote:
| [deleted]
| NovaVeles wrote:
| > "It's not physics, it's engineering,"
|
| When it comes to fusion I am always in too minds about
| statements like this.
|
| On one hand, yeah, it is something that we may be able to
| wrangle into something useful.
|
| On the other, fusion can be seen as a perpetual motion machine
| that doesn't defy the laws of physics. It can kind of inhabit
| that same mind space.
| YZF wrote:
| Right. It's not physics (though arguably plasma isn't that
| well understood but let's ignore that) it's just incredibly
| difficult engineering and needing to solve multiple extremely
| difficult engineering problems. In that same sense reversing
| climate change is just an engineering problem, populating
| Mars is just an engineering problem, a space elevator to
| orbit is just an engineering problem, quantum computers etc.
| etc. ;)
| pfdietz wrote:
| Engineering issues are perfectly capable of ruining the
| prospects for a technology, even if they are "lower class"
| than physics issues.
| Schroedingersat wrote:
| Case in point. Hydrogen energy storage.
|
| It's so very nearly amazing in several different formats
| and applications. Net result is it's kinda okayish in a
| couple of niches.
| pfdietz wrote:
| Those niches look very important, though, especially for
| reaching a 100% renewable energy system.
| ncmncm wrote:
| That is why it has this unholy fascination, and distracts
| attention from things that actually work here and now. It is
| pernicious that way.
| empiricus wrote:
| What if instead of this huge engineering efforts (with no end in
| sight) you can just put two rocks together and get heat/energy?
| That is called fission btw.
| johndhi wrote:
| What % chance do we feel that we will have fusion power within
| the next 50 years?
| sien wrote:
| On Metaculus :
|
| Most likely - fusion ignition in the 2030s. Fusion supplying
| 10% of global electricity in the 2050s.
|
| https://www.metaculus.com/questions/?order_by=-rank&main-fee...
| zardo wrote:
| Those two predictions don't seem to fit together.
| kortex wrote:
| Why? Even once you figure out ignition, you still have a
| bunch of engineering issues to tackle. Energy extraction,
| tritium breeding, reactor longevity, reducing the build
| time and cost. Hopefully most of that can be figured out in
| parallel while we inch closer to ignition, but it's not
| like once we get ignition we can just copy-paste our way to
| actual commercial fusion power production.
| zardo wrote:
| Because going from the science project has finally worked
| to supplying 10% of the worlds electricity in just 20
| years would be a truly incredible pace progress.
| ForHackernews wrote:
| Mobile phones went from 0.001% to 12.0% adoption from
| 1980 to 2000[0]. Things can happen quickly if there is
| very obviously lots of money to be made.
|
| [0]
| http://stats.areppim.com/stats/stats_mobilexpenetr.htm
| zardo wrote:
| > Things can happen quickly if there is very obviously
| lots of money to be made.
|
| There is not obviously lots of money to be made in
| rapidly building out fusion power plants.
| yreg wrote:
| This site seems interesting, thanks. Never heard of it.
| mkaic wrote:
| 90%. I'm not qualified in the _slightest_ to make that
| prediction but I 'm making it anyways!
| fibonacc wrote:
| 99% but petrodollar will still be in power. Access to fusion
| power will be strictly controlled.
| ncmncm wrote:
| Exactly 0%.
|
| Achieving stable fusion does not make practical power from it
| possible. It would necessarily cost >10x fission, and fission
| is not competitive.
|
| We can be absolutely ,confident that by 2100, there will have
| been zero kWh of commercial power from Tokamak fusion. It is
| just barely possible that D-3He fusion might work by then, but
| it would still struggle to compete. It might find use in outer-
| solar-system spacecraft.
| weberer wrote:
| Construction of the DEMO plant is currently set to begin in
| 2040. It is made to follow ITER, so any delay in ITER will
| propagate to DEMO.
|
| https://en.wikipedia.org/wiki/DEMOnstration_Power_Plant#Time...
|
| https://en.wikipedia.org/wiki/ITER
| DennisP wrote:
| Yes but ITER is the world's slowest fusion project. Now we
| can build much smaller reactors, much more quickly, with the
| same output because we have better superconductors. Several
| startups are tackling it, and a lot of fusion scientists
| think CFS will beat ITER to net power by a decade.
| foolfoolz wrote:
| the U. S. has spent more on ukraine in the last year than
| on ITER since it's inception. ITER isn't slow because it's
| big it's slow because of how it's funded
| DennisP wrote:
| But the US alone has spent more on ITER than CFS will
| spend on SPARC.
|
| This isn't entirely ITER's fault. The superconductor
| technology SPARC is using didn't exist when ITER was
| designed.
| myrmidon wrote:
| It sure might be faster to experiment with new tech if your
| reactor is toy-sized, but building the whole thing at a
| scale that's somewhat realistic for economically generating
| power seems an un-avoidable step to me.
|
| ITER is doing that NOW and NONE of headline-generating
| startups have even started...
|
| So it seems to me that ITER is both contributing more
| engineering insights and _closer_ towards a full-fledged
| fusion power-plant, and unlikely to be overtaken in these
| regards anytime soon, if ever.
| DennisP wrote:
| Tokamak output scales with the square of plasma volume,
| but the fourth power of magnetic field strength. Double
| the field, 16X the output.
|
| We have superconductors now that can support much
| stronger magnetic fields than ITER uses. That lets us
| build smaller tokamaks with the same output as ITER.
| Several startups are using them, led by MIT spinoff CFS.
| Their SPARC reactor should have output similar to ITER's,
| in a reactor half the size of JET, which was built in a
| year. They expect to attempt net power in 2025 and a lot
| of researchers think they'll succeed.
|
| Assuming that works, as similar reactor the size of JET
| gets them to commercial output levels.
| myrmidon wrote:
| My point is that ITER is designed for 500MW (thermal)
| output. SPARC aims for something around 100MW (and is
| even further from continuous operation than ITER by
| design), and even the ARC successor (which is currently
| basically a pipe dream) is going to catch up with ITER in
| output power at best.
|
| So even IF the whole SPARC thing goes according to play,
| it's going to be miles away from anything resembling a
| competitive power plant, while ITER is potentially
| something like a quarter way there (assuming that
| operating at 2GW thermal begins being somewhat
| attractive/feasible for a fusion-powerplant).
|
| Personally, I strongly doubt that fusion power is EVER
| going to be an option because of simple economics; I just
| don't really see how a vacuum chamber surrounded by
| superconducting magnets, cooling systems, turbines and
| turbogenerators is ever going to compete (financially)
| with just slapping PV panels on a roof, putting some
| battery banks in the basement, hooking it up with an
| inverter and just repeating as necessary until power
| demands are met...
| DennisP wrote:
| Bigger is better only if it gives you a better ratio of
| capital expense to output. Due to the magnetic scaling I
| mentioned, SPARC/ARC probably does significantly better
| on that front.
| myrmidon wrote:
| My point is that any commercial plant MUST be big enough
| to supply a generic steam turbine setup with heat; every
| fusion reactor design that cant achieve that is just a
| glorified toy, because it CANT operate economically.
|
| A bigger research reactor is simply better in that it
| enables you to investigate/solve problems that are
| related to scale, and all those MUST be solved before a
| commercial plant can be built.
|
| Until ARC or an even further removed successor catches up
| to ITER in size/power, the SPARC project is just yet
| another toy reactor IMO.
| DennisP wrote:
| The US has 37 coal plants below 10MW, 73 plants from 50
| to 100MW, and 85 plants between 100 and 250MW:
|
| https://www.gem.wiki/Existing_U.S._Coal_Plants#Size_compa
| ris...
|
| Coal plants of course use steam turbines:
|
| https://www.tva.com/energy/our-power-system/coal/how-a-
| coal-...
| anigbrowl wrote:
| 73%
| idontpost wrote:
| 0% chance.
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