[HN Gopher] Space-based solar power is getting serious
___________________________________________________________________
Space-based solar power is getting serious
Author : rbanffy
Score : 123 points
Date : 2022-10-20 11:36 UTC (3 days ago)
(HTM) web link (www.science.org)
(TXT) w3m dump (www.science.org)
| ilyt wrote:
| schiffern wrote:
| ... and that's a problem.
|
| I can't imagine an idea that's _worse_ for space debris than
| SBSP. It necessarily requires huge masses, and huge surface
| areas. Total mass in an orbit is what determines if you 're past
| Kessler's "tipping point." Total surface area is what determines
| how quickly the system erodes into tiny MMOD pieces (each MMOD
| impact releases 100x as much mass as the impactor itself).
|
| The usual lazy rebuttal is that the preferred orbits are
| _currently_ unpolluted. To that I say, with that attitude how
| long do you think it will stay that way?
|
| The remaining "pristine" orbits are so high up that all the
| debris generated is effectively eternal.
| detritus wrote:
| 'MMOD'?
| Sharlin wrote:
| Micrometeoroid and orbital debris.
| cletus wrote:
| Here is my hope (and my belief): the ultimate end here is orbital
| rings [1]. To summarize the video, you can put copper cabling in
| orbit, run a current through it and keep things in place
| (relative to a point on Earth) with magnetic levitation.
|
| The most important part of this is that you can have things in
| LEO that are fixed to Earth points. Why does this matter? No
| longer do you have to speed up to Mach 30 to reach orbital
| speeds. You could technically run a cable from 150km up and carry
| people and goods from Earth into LEO and back. This could
| revolutionize long-distance travel on Earth too.
|
| It's estimated that a space-based power collector could create
| about ~7 times the energy of an Earth based collector due to less
| power loss from the atmosphere and night (to be clear, a solar
| collector in orbit would still occasionally be occluded by the
| Earth but it won't be half the time).
|
| You can get power down to Earth in two ways: you can transmit it.
| This is actually viable but is not ideal. Alternatively, if you
| have an orbital ring, you can attach it to that and just run
| cables down to Earth. We use longer power transmission lines than
| that on Earth already.
|
| All of this requires no new physics, no magical materials (eg
| space elevators do) and are just (admittedly massive) engineering
| projects. If you can get solar panels into orbit for <$10/kg
| payload costs and run cables down to Earth, you'll solve the
| variance issue with solar and create cheap power on a massive
| scale.
|
| And none of this requires commercially viable fusion (which I'm
| not yet convinced will ever happen) or even the serious
| externalities of nuclear fission power.
|
| [1]: https://www.youtube.com/watch?v=LMbI6sk-62E&t=62s
| ilyt wrote:
| thenewthotness wrote:
| I did a back of the napkin calculation a while ago regarding
| how many car lengths you'd need to put in LEO to have an
| unbroken traffic jam in orbit and the result was surprisingly
| comparable to the number of cars we're currently producing. If
| you were "simply" launching wire instead I'm sure you could get
| enough material up there in much fewer launches. I'm curious as
| to how you would construct such a loop since you'd need to
| station keep it somehow while it's inoperable.
| cletus wrote:
| You can build it in sections because the wire itself is
| travelling at orbital speeds. That's actually what makes the
| whole thing work. Running a curent through that creates an
| electric field. You would probably encase the whole thing and
| contain it with a magnetic field. You would then build things
| on top of that casing.
| var_cw wrote:
| wow this is such an incredible idea
|
| reminds me of the earth-moon fire pole
|
| https://what-if.xkcd.com/157/
| cletus wrote:
| So this clearly wouldn't work but it is a fun thought
| experiment. Thing is, there are places that it would work.
| Pluto and Charon notably are tidally locked to each other and
| have muich lower gravity and much lower distance (~12K
| miles).
| jtbayly wrote:
| What kind of cable material do we have that can support its own
| weight for that many miles vertically?
| Schroedingersat wrote:
| Copper is not strong enough, and steel isn't quite strong
| enough to hold itself up with constant cross section.
|
| Carbon fiber is, or you could just have a tapered steel or
| aluminum cable.
|
| The loop could be anything as it's under zero G. You'd need
| counterweights above it.
|
| You only get access to the equator without some kind of
| bizarro maglev hula hoop contraption which would level a
| country if anything went wrong, and the equator doesn't
| really need help with solar or solar storage as PV+CSP works
| quite well there.
| elif wrote:
| My man said copper XD
| lostlogin wrote:
| Going with what you're saying, a better use of the tech would
| be to supply electricity to places that currents rely on
| generators. There are islands that use diesel generators md
| burn a mass of fuel where electricity could be beamed in,
| Rarotonga for example.
| cletus wrote:
| So I don't think fossil fuelds will completely go away. It's
| just that most use cases will be eliminated once there is a
| cheaper and equially suitable method of power generation.
|
| I strongly believe in the future of solar power in general
| because it's relatively low-tech and reliable. There are no
| moving parts (other than maybe turning an array to face the
| Sun while it moves across the sky but this isn't strictly
| required). So solar power can provide power in a lot of
| places where it's either impossible or infeasible to build
| infrastructure (eg remote places, war zones).
|
| But once solar power source (or something else) is cheaper
| than burning oil, gas or coal you can use that power to make
| fossil fuelds by sequestering carbon from air. That's not
| that difficult but we don't generally do it because it makes
| little economic sense. But this method would make fossil
| fuelds essentially carbon neutral.
|
| So there are vehicles that won't make sense to be replaced
| with EVs. Likewise, there are places where burning fuel may
| still make snese. Solar power may not make sense in jungles
| or hurricane zones so there may be continued use of
| generators. I can't speak to the specifics of Rarotongo. In
| general though, I think the technology and infrastructure
| will be truly transformative on a massive scale.
| grecy wrote:
| Not just little islands either.
|
| I was at a radio transmitter[1] on the West Coast of
| Australia the other day. It's the largest low frequency radio
| in the Southern Hemisphere, used by subs and military stuff.
|
| The facility, which is 6 kilometres from a regular town, and
| has three diesel generators producing 18,000,000 watts of
| power, burns through 26,000 litres of diesel PER DAY. It's
| been doing that 24/7 since 1967. (There was a sign proudly
| stating as much)
|
| We do a TON of stupid stuff, regularly.
|
| [1] https://en.wikipedia.org/wiki/Naval_Communication_Station
| _Ha...
| kQq9oHeAz6wLLS wrote:
| If it's stupid, but it works...
|
| Now, how expensive - and how big - would an equivalent
| solar array be? Don't forget maintenance costs, including
| technicians.
|
| Once all that is cheaper and just as reliable as their
| generators, only then will there be a discussion on
| replacement.
|
| But in general, I agree that it should be done.
| lostlogin wrote:
| > Now, how expensive - and how big - would an equivalent
| solar array be?
|
| Surely a 6km cable is the solution?
| marcosdumay wrote:
| Solar is the lowest maintenance source we have, so yeah,
| make sure to add maintenance. (It's more expensive with
| batteries, but compared with diesel, it's ridiculously
| cheap.)
| noogle wrote:
| What about maintenance of the physical structure? PV
| panels have no moving parts but:
|
| 1. The inverter and other electrical systems do fail
| (surprisingly frequently).
|
| 2. Solar is very spread-out: maintaining a geographically
| large facility is not trivial (vegetation, water
| drainage, cables etc.)
|
| 3. Batteries also require maintenance, and are an
| inherent part of any independent PV installation (if the
| site relies on the grid, it is no longer independent).
| vitus wrote:
| > Now, how expensive - and how big - would an equivalent
| solar array be? Don't forget maintenance costs, including
| technicians.
|
| For an easy point of comparison, there actually is an
| 18MW solar array under development in western Australia
| as part of phase 0 of the Yuri project [0] (the goal of
| that project is to produce hydrogen for ammonia
| production via electrolysis instead of steam methane
| reforming). This is apparently around 23 hectares (57
| acres), at a cost of A$24-33m in capital expenditures,
| and A$0.5-1.5m in annual operating expenses [1].
|
| For comparison, let's suppose diesel is A$2 / liter.
| 26,000 liters a day, for 365 days a year, is A$19
| million, every year, just for fuel costs. Wait, you might
| argue, fuel prices are inflated this year. Okay,
| historically it might have been closer to A$1/L, for
| about A$10 million per year. Breakeven is therefore
| somewhere in the ballpark of 2-4 years, which is absurdly
| low for a project of this scale.
|
| [0] https://gateway.icn.org.au/project/4938/yuri-phase-0
|
| [1] Page 28-29 of
| https://arena.gov.au/assets/2020/11/engie-yara-renewable-
| hyd... -- capex estimate is A$70m. If you remove the
| capex of building the H2 plant, you're left with A$33
| million. If you just consider the PV component (34% of
| the overall capex estimate), then you get A$24m.
| ben_w wrote:
| This will absolutely work (and unlike beamed power, can
| provably avoid being used directly as a weapon by malicious
| actors); _but_ , when you get to the scale "chonky enough you
| can attach a cable down to ground level", you might as well
| just build on the ground in the first place. A few square
| meters cross section is enough for a global HVDC grid using
| boring copper and/or aluminium, the losses aren't worth caring
| about given how cheap PV is even now.
|
| Active support towers going up, that may work (if we solve the
| engineering issues, AFAIK nobody has tech demoed it yet), as
| those don't need to be supported by the cable, meaning the
| cable can be much smaller.
| elif wrote:
| The fact that one company is already producing the cheapest
| rockets, cheapest satellites using directed microwave beams from
| LEO and shares ownership with one of the largest solar
| manufacturers in the country leads me to believe that it is an
| economics problem more than an engineering problem.
| gwbas1c wrote:
| Can this somehow beam power in such a way that we can direct it
| to the parts of the planet that are currently in the winter and
| need it for heat?
|
| I didn't find a mention of seasons, winter, cold, heating. (I
| skimmed the beginning of the article.)
|
| The biggest obstacle to solar is the seasons: We use the most
| energy in the winter (for heating,) but most of the sunlight
| comes during the summer. There are locations in the far north
| where there is simply no sunlight at all during the "day."
| tpudlik wrote:
| Relatively little energy is actually used for heating and
| cooling. In the UK, a country pretty far north, it's about a
| fifth of energy use
| (https://www.withouthotair.com/c7/page_53.shtml), and could be
| substantially reduced if heating was actually done using
| electricity (i.e., with heat pumps, rather than direct heating;
| heat pumps are available with "efficiency" exceeding 400%, e
| http://www.withouthotair.com/c21/page_140.shtml, but of course
| require electricity to run, while most heating today is done by
| directly burning fuel).
|
| Seasons are definitely not "the biggest obstacle to solar".
| That would be the night and especially the weather.
| iefbr14 wrote:
| I am afraid it won't be built for a peaceful purpose..
| kortex wrote:
| Ion canon ready...
|
| I could see a microwave power satellite being deployed despite
| obvious cost inefficiencies, specifically because of the
| ability to zap things (defensive, hopefully ).
|
| It could also be helpful anywhere needing mobile short term
| power, eg forward operation bases.
| [deleted]
| kkfx wrote:
| There are hyper-big issues:
|
| - in Space micrometeorites and mere high energy received from the
| Sun deteriorate anything quickly OR it's not much a matter of
| launching something but keep it operational changing a piece at a
| time;
|
| - it does not scale AT ALL because even at very low price of
| anything the cost is so extreme that we need something so cheap
| like "hey this WE instead of a trip nearby I go for an orbital
| trip, the price is roughly the same";
|
| - microwaves transmission will probably be very harmful for
| human, nature in general and a big potential danger is a beam
| move/is traversed by accident.
|
| The general real issue we have with renewables is:
|
| - they are intermittent, our needs does not match, storage is
| needed to combine supply and demand but effective storage ON
| SCALE is missed and not foreseeable in a near future [1]
|
| - anything must be designed to handle and profit of peak
| productions, the very opposite of ANYTHING we have built so far,
| from grids built at a certain size and interconnection to average
| the load as maximum to mere water heaters designed to run few
| minutes per hours instead of hyper-full-power for few hours per
| day
|
| - we are still in a linear supply chain model, p.v. panels and
| lithium storage recycling is THEORETICALLY described but nothing
| exists on scale so far and probably will not appear in a short
| period of time
|
| Just as an example my home-made p.v. plant cost around the price
| of mid-range "cheap" ICE car for around 10 years of expected life
| (sure modules last longer, but when lithium is depleted and
| inverters start to age there is no sense in keep old modules, the
| cheapest part, anymore), even with it I'm far from being
| autonomous, o sure, FORMALLY I can produce 120/130% of my overall
| consumption (except the new EV) BUT practically I can reach 50%
| self-consumption. And that's a new, well insulated home, with
| various stuff to maximize self-consumption since exactly NOTHING
| exists on sale with such target, even devices who claim to be
| designed for that. And the home is in the France south alps so in
| a very good location for p.v., many live far northern.
|
| My conclusion so far is: it's ok-ish to push the accelerator on
| renewables to improve them since PUBLIC research in the modern
| financial-driven society lacks, but we are FAR, FAR, FAR behind
| what managers think we are or at least can be. To avoid hyper-big
| disasters we have just nuclear, fossil while we create new NPP,
| nation-wide plan to rebuild homes etc. Something THEORETICALLY
| doable in no less than half a century. In practice probably few
| centuries. I'm not joking. Those unconvinced: try yourself and
| see results. Mine say what I said above.
|
| [1] effective means 6 month storage for a country of any size on
| it's own land, because yes energy is serious and we can't risk
| more than that at such a scale.
| JoeAltmaier wrote:
| Read the article? It addresses much of that.
| photochemsyn wrote:
| The general concept of beaming power from point A to point B
| using microwaves is itself interesting, and is a nice historical
| throwback to ideas that Nicolai Tesla was promoting in his later
| years. However, this is almost certainly little more than a niche
| market for specific applications, and notions about using giant
| space-based platforms to collect energy and beam it to earth to
| power factories, cities, and homes are nothing but unrealistic
| sci-fi concepts. It's comparable to notions that fossil-fueled
| global warming could be fixed by parking a giant sunshade out at
| Lagrange 1.
|
| It's just far more efficient to build solar PV arrays on the
| ground, and to keep power on 24/7, build enough to store the
| energy for later use at night and in the winter. Throwing all
| that mass into orbit, even if in low-Earth orbit where decay and
| burnup in the atmosphere is guaranteed over time for the debris
| issue, is just a massive waste of resources, plus the energy loss
| over 100 km or so would undoubtedly very high.
|
| Here's a list of more realistic applications (with a rather
| military-industrial flavor, although space exploration
| applications also exist):
|
| > "At the U.S. Naval Research Laboratory, we have spent the
| better part of the past 15 years looking into different options
| for power beaming and investigating potential applications. These
| include extending the flight times and payload capacities of
| drones, powering satellites in orbit when they are in darkness,
| powering rovers operating in permanently shadowed regions of the
| moon, sending energy to Earth's surface from space, and
| distributing energy to troops on the battlefield."
|
| https://spectrum.ieee.org/power-beaming
| noogle wrote:
| > It's comparable to notions that fossil-fueled global warming
| could be fixed by parking a giant sunshade out at Lagrange 1.
|
| Why can't it work? Critics of this idea often cite cost or
| unintended consequences, but not ineffectiveness at mitigating
| the temperature rise (ocean acidification etc. are a different
| issue).
| Maursault wrote:
| My criticism is a massive L1 sunshade does absolutely nothing
| to solve the underlying problem, merely mitigates one of its
| effects while suppressing photosynthesis, reducing that
| aspect of the planet's ability to attack the underlying
| problem. There is only one solution to the problem which is
| to stop dumping carbon into the atmosphere and accept the
| consequences for our lifestyles. The Earth will take care of
| the rest.
| noogle wrote:
| This has been debated at length at the past, so I'll pass
| on that discussion.
| sjducb wrote:
| I disagree with the niche market thing.
|
| #1 Military forward operating base #2 Anything that has to be
| in the middle of nowhere, think mining and agriculture, maybe
| even oil rigs #3 Shipping, it could make electric container
| ships viable. #4 Anyone who wants to rent their power, rather
| than build their own panels. You're shifting CapEx to OpEx.
| This is why cloud computing took off. You can have any amount
| of power you need at the flip of a switch. People will pay a
| massive premium for that.
| dmd wrote:
| You say "I disagree with the niche market thing" but then as
| a counterexample give four niche markets.
| macintux wrote:
| Container ships are a _huge_ market.
| photochemsyn wrote:
| I think the costs are going to be astronomical, and that's
| the difference with cloud computing - if it cost 10X as much
| to use AWS as it did to run your own servers onsite with IT
| people to manage them, AWS would never have taken off.
| Likewise, for mining and agriculture, onsite solar/storage is
| almost certainly going to be much cheaper. Electric container
| ships are an interesting idea, but even there it might
| actually be cheaper to just synthesize fuel from water and
| air.
|
| In particular, transmission losses and low efficiency seem to
| be the fundamental problem. See previous discussion:
|
| https://news.ycombinator.com/item?id=31521665
| onlyrealcuzzo wrote:
| > Electric container ships are an interesting idea, but
| even there it might actually be cheaper to just synthesize
| fuel from water and air.
|
| How does one do this without power? And if possible, why
| isn't it done already?!
| ch4s3 wrote:
| You'd do it at the port with nuclear/wind/solar. No one
| does it now because marine fuel is super cheap.
| [deleted]
| manholio wrote:
| For a given mass of solar panels, the space version is
| perhaps 50% more efficient, due to the fact they operate in
| space. Putting them there, in the most optimistic scenario,
| will cost perhaps 100x versus the ground level version.
| Currently it's something like 1000x, but let's asume prices
| go down due to Starship and what not.
|
| So you really have to ask what kind of practical scenario
| affords you to use energy that is at least 60 times more
| expensive than what is available at ground level (but more
| realistically, at least 300-400x). Even if you include the
| capital cost of Li-ion batteries, their wear and tear and
| road transport for over 1000 miles, you can still get power
| much cheaper by just trucking batteries around. That, mind
| you, is before any transmission loses, investment in ground
| infrastructure etc., it makes no sense to put solar panels in
| space because the efficiency gains are simply too limited.
|
| This leaves the military scenario indeed - which is basically
| sci-fi, but bras has been known to abandon common sense when
| planning technology, see the initial Space Shuttle concept,
| space laser weapons etc.
| coryrc wrote:
| In space they generate ~7x as much power averaged over the
| day (24hr sunlight, plus full power all the time) and
| during the winter in the upper latitudes it has got to be
| at least 100x the power you get from one on the ground.
| DennisP wrote:
| People drastically underestimate how Starship will change
| launch costs. Right now they throw away an expensive upper
| stage with every launch, and even the lower stage only gets
| used about a dozen times. Starship doesn't throw away
| anything and it's designed to be used about a thousand
| times. At scale it's basically just the cost of fuel and
| ground services, which drops cost by a couple orders of
| magnitude.
|
| The book _The Case for Space Solar Power_ has detailed cost
| estimates for NASA 's SPS-ALPHA design. It was published
| about a decade ago so has old launch costs. I plugged in
| Starship costs and got a total cost of $0.04/kWh, which is
| pretty great for dispatchable power without needing
| storage.
| kiba wrote:
| The real money comes from using starship to develop
| spaced based industrial capacity. Instead of
| manufacturing solar panels on earth, it would be
| manufactured in space. Once we have real space industry,
| doing things in orbit would be much cheaper.
| [deleted]
| danans wrote:
| > Instead of manufacturing solar panels on earth, it
| would be manufactured in space. Once we have real space
| industry, doing things in orbit would be much cheaper.
|
| The raw materials would still need to be shot up into
| space. And what makes manufacturing and assembly in
| zero-g cheaper than on the Earth's surface?
| r2_pilot wrote:
| The idea is probably using ISRU(in-situ resource
| utilization) with regards to local asteroids to save on
| launch costs. Manufacturing/assembly would likely be more
| expensive at first until the techniques and technologies
| are learned(perhaps one could upsell this as "truly green
| manufacturing" since there would be no environmental
| byproducts to affect Earth).
| danans wrote:
| > perhaps one could upsell this as "truly green
| manufacturing" since there would be no environmental
| byproducts to affect Earth
|
| Except for the massive byproducts created on earth to get
| through the "more expensive" phase. It would be deeply
| deceptive and cynical to sell that as "green", surpassing
| even today's deceptive selling of carbon capture and
| storage technology on fossil fuel power plants.
| [deleted]
| thangalin wrote:
| #2 Radio communications, mountain-top repeaters. Not dropping
| $4k on chopper rides to battery swap would be a boon for the
| environment and bank accounts.
| nanomonkey wrote:
| Powering cargo planes seems like a niche market that would be
| suitable. The planes could have just enough power to get up
| above the cloud layer, then receive a charge boost each time
| they go below each solar powered satellite. This makes the
| planes lighter as they no longer need to carry as much fuel or
| batteries.
|
| A second consideration is that these satellites can be
| factories in space. Raw materials are much easier to launch
| into space using rail guns as the materials can survive higher
| g forces then humans or pre-manufactured goods. Once in space,
| the raw materials can be made into higher quality goods due to
| the lack of atmosphere and gravity. Once they are in space they
| can be put to use making further satellites, orbital rings or
| habitats.
| bastawhiz wrote:
| Call me old fashioned, but the thought of putting a massive,
| heavy tube into the air full of cargo without enough energy
| to get it to its destination seems like an idea that will get
| a lot of people killed. I can't even get reliable satellite
| TV, I don't want "keep a plane of Amazon packages from
| landing in my attic" reception to be a thing I need to think
| about.
| bergenty wrote:
| Unmanned cargo planes with fail safes over ocean routes
| doesn't seem too dangerous.
| krasin wrote:
| The primary use case here is trans-pacific. Not a lot of
| attics out there.
| akira2501 wrote:
| "Yea.. if it crashes, it just crashes into the ocean.
| What would the problem with that be?"
|
| Move fast and break things as applied to air transport
| really makes for some exciting opportunities, doesn't it?
| krasin wrote:
| We can either be infinitely scared and do nothing or we
| can actually make progress in a responsible manner and
| get a chance to fix climate.
| akira2501 wrote:
| This is not a responsible solution, and believing so
| doesn't belie some "infinite fright," nor does it
| discount the thousands of more reasonable solutions that
| could be applied here first.
|
| If you honestly thought "space based power beams" were a
| realistic solution, then why you would even propose a
| plane as opposed to a boat is entirely beyond me. This
| idea that we're just going to find some "plug in"
| solution to our current infrastructure that's suddenly
| net positive for the climate only invites these kinds of
| irresponsible flights of fancy.
|
| If you want an honest solution, then you're going to have
| to reconsider the mechanisms that cause you to fly cargo
| across the globe on jets in the first place. These
| systems were built for profit, and they continue to
| operate with profit as their primary motivation. If you
| want to manage the climate "responsibly" then you need to
| put it first, and when you do so, you realize that our
| current means of distributing products around the world
| is patently insane.
|
| Only by ignoring that problem or hoping that literal
| "power beams from outer space" will magically become
| available and prevent any restructuring of profit flows
| leads to this kind of nonsense thinking.
| Someone wrote:
| > Powering cargo planes seems like a niche market that would
| be suitable
|
| FTA: _Most designs aim to produce a beam kilometers wide so
| that any spacecraft, plane, person, or bird that strays into
| it only receives a tiny--hopefully harmless--portion of the
| 2-gigawatt transmission_
|
| 2 GW on a _single_ km2 is 2kW per m2, about twice what solar
| power provides. "Kilometers wide" could easily mean 10km2, or
| 200W/m2.
|
| = it will be difficult to get the power density to power an
| airplane, even if it's only for flying at height.
| robbiep wrote:
| I think your maths is off - there are 1m square metres in 1
| sq kilometre, but 2000 kW in a GW, meaning approx 0.002 kW
| per square meter.
|
| Which kind of makes this whole thing a weird economic
| proposition. You're beaming energy from space at a density
| that approximates solar insolation, and still have to build
| the collector and convert it back - wouldn't it be easier
| to just collect the solar insolation?
| IanCal wrote:
| > I think your maths is off - there are 1m square metres
| in 1 sq kilometre, but 2000 kW in a GW, meaning approx
| 0.002 kW per square meter.
|
| That's not right. There's 2000 kW in a MW, not GW. 2GW is
| 2e9W, so over 1e6,^2 that's 2e3W/m^2 or 2kW/m^2.
| robbiep wrote:
| Ahh thankyou for sorting me out. My apologies OP
| Schroedingersat wrote:
| There are already planes that can fly (and do nothing else
| useful) on 300W/m^2
|
| Solar panels already have sufficient mass power density.
| There's a pretty big gap between the 10s of MW a jumbo
| needs and the 700m^2 of area it has. If you were willing to
| trade some flight speed you could increase wing area 5x or
| so, and maybe make it work in the 2-4kW/m^2 range if all of
| the photons were at your bandgap.
| BiteCode_dev wrote:
| Also, the first accident (there is always one) redirecting the
| beam to a populated area is going to be so spectacular I doubt
| it would recover after it.
| ben_w wrote:
| Accidents probably won't be an issue (useful power density is
| surprisingly safe, and safeguards can be put in); _malicious_
| redirection of multiple beams, that probably is a threat.
|
| Multiple beams can only be _guaranteed_ safe against
| malicious agents by making sure only one is in any given
| person 's sky at any given moment, which _either_ limits us
| to 6 worldwide _or_ requires the satellites to be low enough
| that they 're in earth's shadow.
|
| (Last time I said this on HN, I got an angry response from
| someone who clearly didn't understand what I was saying; I
| don't know if that is because words are bad at painting
| pictures or not, but regardless I _really_ ought to get
| around to blogging this with pictures to show what I mean).
| dsign wrote:
| > It's just far more efficient to build solar PV arrays on the
| ground, and to keep power on 24/7, build enough to store the
| energy for later use at night and in the winter. Throwing all
| that mass into orbit, even if in low-Earth orbit where decay
| and burnup in the atmosphere is guaranteed over time for the
| debris issue, is just a massive waste of resources, plus the
| energy loss over 100 km or so would undoubtedly very high.
|
| That argument makes perfect economic sense ... now. The same
| way that burning fuel still makes economic sense in quite a few
| cases. But environment anxiety is not only about burning fossil
| fuels, it is about deforestation, farting cows, the use of land
| for human activities, and well, basically every industrial
| economic activity. There is environmental anxiety about solar
| and about wind energy production, and about nuclear power. And
| it is often an-out-of-the-blue spurt for something that happens
| in another continent[^1]. We are slowly but surely channeling
| that anxiety by taxing "Earth use".
|
| Here is a thought experiment: try to imagine a world where
| human environmental footprint is bound in a way that satisfies
| even the most extreme environmentalists today, who--as anxiety
| raises--are going to be your average bread-and-butter
| (self-)conscious citizen of tomorrow. How does it look? How
| many of us?
|
| I wish we come upon a time when we decide to have space-based
| solar power and space-based living. The alternative is
| disquieting.
|
| [^1]: https://www.bbc.com/news/topics/cjyykdwmw58t
| Schroedingersat wrote:
| Emigration and performing energy intensive work where the
| heat can just radiate away makes sense, but a world in which
| we pump 100s of Terawatts through the atmosphere as
| microwaves because we are dissatisfied with the 100s of
| terawatts falling on areas we have already paved is not one
| driven by environmentalism, but by avarice.
| flareback wrote:
| I always wonder about the health effects of beaming energy to
| earth on the people near the beam. What keeps the beam narrow to
| the just the intended collection point? The article states it's
| microwaves and that doesn't sound healthy to be bombarded by
| microwaves. Is there something here that I'm missing about how
| they're transmitting the energy?
| hedora wrote:
| They claim it will be such a wide beam that it won't matter
| (multiple square miles of beam per city).
|
| I haven't done the math, but it sounds wrong to me too. It
| would be nice if they provided actual wattage in the same units
| that are currently used for consumer devices, like cell phones.
| hopeimanon wrote:
| The launch costs seem resolvable but
|
| What do the plans to make transmission cheap/efficient look like?
| Where would i read more detail?
|
| Safe beams don't have much more power than the sun so don't seem
| too economical compared to normal solar panels. And most niche
| applications need greater power density to benefit
| DennisP wrote:
| See the book _The Case for Space Solar Power_ or NASA 's SPS-
| ALPHA project.
|
| Basic idea is a phased array microwave trasmitter, a
| transmitter on the ground that sends a reference signal, and a
| receiving station that's basically several square miles of
| antenna wire, contributing 0.7 cents/kWh to the total cost.
| dcj4 wrote:
| No it isn't.
| paulsutter wrote:
| A solar-pumped laser could illuminate existing PV solar power
| plants after hours, and simpler because there's no need to
| convert light to electricity to microwave
|
| https://www.nature.com/articles/s42005-020-0326-2
| cbmuser wrote:
| We have nuclear power. We don't need these absurdly expensive and
| complex solutions to harvest solar power or wind.
|
| We should use that money to build more nuclear reactors and
| develop new designs. It's a proven, reliable and inexhaustible
| source of energy.
| goodpoint wrote:
| ..and it's vulnerable to climate change, not to mention war and
| social unrest.
| 504error wrote:
| puchatek wrote:
| Can you please respond to the comments below? I'm tired of ppl.
| bringing up nuclear and then ducking the debate
| pydry wrote:
| Nuclear power is 5x more expensive than solar and wind.
|
| Hell, if you used wind turbines to synthesize gas at ~50%
| efficiency and burn _that_ to generate electricity at ~60%
| efficiency it would _still_ be about 10-20% cheaper than
| nuclear power.
|
| https://theecologist.org/2016/feb/17/wind-power-windgas-chea...
| mrtranscendence wrote:
| Doesn't burning methane seem a bit unfortunate when it comes
| to climate change?
| pydry wrote:
| Not especially. It's carbon neutral.
|
| In general there's no point, it's just an illustrative
| example of the horrendous economics of nuclear power.
|
| It might be a good idea to generate some gas if we one day
| have wind/solar producing >100% of consumption and all the
| batteries/pumped storage are fully charged. That'd be a
| nice problem to have, truth be told.
|
| Currently, wind and solar rarely produce more than current
| demand, ever. Natural gas averages about 40% of our
| electricity supply and rarely if ever goes to zero even on
| the sunniest windiest days. Every MWh produced by wind or
| solar is just another MWh where we dont have to burn gas.
| hedora wrote:
| Methane is a much more potent greenhouse gas than CO2.
| Current systems leak enough to make it infeasible in the
| mediun term.
| argiopetech wrote:
| tsimionescu wrote:
| Nuclear power is definitely nowhere near 5x more expensive
| than solar _in space_ , which is what this article is
| proposing.
| seventytwo wrote:
| Why is nuclear so expensive?
| himlion wrote:
| Because of complexity, safety requirements and disposal of
| spent material.
| hedora wrote:
| If that's true, why is coal cheap? It releases way more
| radiation than nuclear, and kills > 100x more people per
| kWh on average.
|
| Nuclear is expensive because of politics.
| robocat wrote:
| Apart from externalities, there are two other common
| reasons why commenters make wind/solar look wayyy cheaper
| than it is.
|
| 1: Commenters don't compare like-for-like energy
| production, instead they often compare using the nameplate
| capacity e.g. compare construction cost of a 1GW nuclear
| plant with a 1GW solar plant. The right thing to compare is
| GWh produced. Capacity factor converts GW to GWh, and the
| capacity factor for nuclear is about 90% and for solar is
| about 15%[1]. Therefore the equivalent of a 1GW nuclear
| plant is 6GW of installed solar.
|
| 2: Commenters ignore the cost of systems needed to provide
| power in winter on windless dark nights. The real cost of
| wind/solar needs to include the necessary energy storage
| (batteries or pumped hydro or stored chemical energy or
| whatever). Some of that can be overcome by installing
| overcapacity (e.g. install 3x as much GW solar to cover
| aircon usage in early evening in Texas). Nuclear is very
| good at providing power at all times. Storage is very
| expensive - usually doubles or triples the cost of the
| wind/solar installation. The need for storage goes up as
| our dependency on wind/solar power increases.
|
| By ignoring the above, solar/wind can look 5x to 10x
| cheaper than a fair comparison with nuclear. Many
| commenters are not interested in facts or numbers - they
| pick heavily biased numbers to make the argument they want
| to (usually that nuclear = bad).
|
| A worked example of wind versus nuclear using chemical
| storage that shows 10% difference in cost:
| https://theecologist.org/2016/feb/17/wind-power-windgas-
| chea... even with their obvious biases towards wind, and
| comparing against the crappy Hinkley-C, they are really
| struggling to show wind is cheaper.
|
| [1] https://www.statista.com/statistics/799330/global-
| solar-pv-i...
| cassepipe wrote:
| Because it is the only industry that is legally obliged to
| take into account almost all of its negative externalities,
| that is waste management and potential accidents.
| pydry wrote:
| If it did that it would actually be even more expensive.
| The disaster liability cap in America means plants need
| insurance that pays out up to $300 million but no more.
|
| Fukushima cost ~$800 billion, so they are essentially
| subsidized by the general public to the tune of 99.97% of
| what is probably their "real" insurance costs.
|
| So no, we are measurably on the hook for more negative
| externalities than we are for solar/wind.
| ch4s3 wrote:
| A "subsidy" that has never been paid. You'd be hard
| pressed to find a reactor with its backup power in the
| basement in the US, and especially not on the coast.
| pydry wrote:
| >A "subsidy" that has never been paid.
|
| Free insurance is a subsidy. Pretending that it isnt is
| dishonest.
|
| Japan paid $0 in 2010 and by 2012 an $800 billion bill
| came due.
|
| Recent nuclear legislation has focused on extending the
| legal life of aging plants. Nuclear power is getting more
| dangerous in America not safer.
|
| It _ought_ to be a moot point anyway given the extreme
| cost of nuclear power without the subsidy.
| ch4s3 wrote:
| Japan's accident was entirely preventable and a similar
| scenario couldn't happen at any facility in the US.
| Needing to build an ice wall to contain radioactive water
| pumped in from the ocean was a huge portion of the cost
| and truly unique.
| consumer451 wrote:
| > is legally obliged to take into account almost all of
| its negative externalities
|
| I always thought waste disposal was not accounted for.
| Could you point me to any information indicating
| otherwise?
| ch4s3 wrote:
| Sorry for the amp link but here you go https://www.google
| .com/amp/s/www.cnbc.com/amp/2021/12/18/nuc...
| consumer451 wrote:
| Wow! Thanks, I had no idea.
|
| Usually localities fight for federal money, this is one
| case where that appears to not be the case.
|
| That article is a great read in any case.
| ch4s3 wrote:
| Np. You should check out James Mahaffey's books like
| Atomic Awakening if you're interested in the subject.
|
| https://www.amazon.com/Atomic-Awakening-History-Future-
| Nucle...
| gene-h wrote:
| One of the biggest issues with space based solar power(SBSP) is
| RF interference. In order for SBSP to be used for baseload power,
| you need to be able to beam power through clouds which means
| transmitting in the sub-10 GHz range.
|
| Unfortunately, many of these frequencies are used by our tech.
| 2.45 GHz is one of the best frequencies to transmit at, however,
| this now used by wifi and bluetooth. According to this
| paper[0](see figure 55) it is reasonable to expect degradation of
| 2.45 GHz communication thousands of kilometers from the
| transmitter. This is due to the fact that microwaves spread out.
| [0] also points out that harmonics of the transmit frequency,
| which can't be ignored because SBSP transmits gigawatts of power,
| will interfere with licensed satellite transmission bands.
|
| In short, frequency really needs to be allocated, otherwise SBSP
| may really be illegal. There are some good options, at least in
| the US, in the sub-10 GHz range used by few people.
|
| [0]https://ieeexplore.ieee.org/document/9318744
| eminence32 wrote:
| From the article:
|
| > Phased array of transmitters focuses gigawatt-power beam
| anywhere on Earth in line of sight.
|
| I wonder if it's possible to steer the power beam around
| clouds, so you transmit power to whatever ground-station has
| the best view. (Unclear if it makes economical sense to
| overbuild ground-stations just to be able to pick one with a
| clear view of the sky)
| axiolite wrote:
| > Unfortunately, many of these frequencies are used by our
| tech.
|
| So what? Microwave frequencies aren't entirely line-of-sight,
| but they aren't going to diffuse very far off-target. Unless
| you have houses in between elements of the receiving antenna
| array, the disruption of comms in the immediate area isn't
| going to actually affect anybody. Perhaps there's some risk to
| jets that choose to fly through the energy beam.
| rcxdude wrote:
| Yeah, but that directionality is bumping up against the
| vastly different levels of power: you don't just need a
| little attentuation between your target and the wifi, you
| need something like 12 orders of magnitude attenuation.
| That's not so easy over long distances. See the paper OP
| cited which does actually do the math instead of handwaving.
| gene-h wrote:
| The transmitter would be located in geostationary orbit
| ~35,000 km away from the receiver, so spread due to
| diffraction becomes significant. With 6.7 GW of transmitted
| power at 2.45 GHz, ~790 MW ends up in the side lobes[0]. So
| it is reasonable expect RF interference not only near the
| receiver, but thousands of kilometers away from it. Figure 55
| in [0] shows a plot of incident power with distance from the
| receiver. As this spread is due to diffraction, the only way
| to lessen it using the same frequency is to build the
| transmitter larger. In the case considered here, the transmit
| aperture was already 1 km.
|
| [0]https://ieeexplore.ieee.org/document/9318744
| Schroedingersat wrote:
| How about we don't use 10 kg of fossil fuel derived methane to
| launch a 100W solar panel which will likely last 1/10th as long
| and cost 100x as much just so it gathers 3x the energy?
|
| Sure we might be able to make the methane with sunlight, but
| having that ability removes the point of doing it in the first
| place.
| mlindner wrote:
| It doesn't even gather any additional energy, once you factor
| in transmission losses from the very inefficient long distance
| power beaming.
|
| Unless you're trying to build solar power north of the arctic
| circle I really don't see the need for such systems.
| XorNot wrote:
| No but it produces reliable solar power. Its never cloudy,
| and with the right alignment some part of it can always be in
| sun shine (do something with Lagrange halo orbits and a
| single installation can be continuously powered).
| mlindner wrote:
| > Its never cloudy, and with the right alignment some part
| of it can always be in sun shine (do something with
| Lagrange halo orbits and a single installation can be
| continuously powered).
|
| If it's using visual/infrared lasers, it absolutely can be
| blocked by clouds.
|
| If it's using microwaves, it absolutely can still get
| weather fade during storms when it's trying to punch
| through a tremendous amount of water in the atmosphere.
|
| And if it's out at lagrange halo orbits, it's not going to
| be doing any power beaming at all, as that's much too far
| to be useful unless we're planning on building dishes that
| are hundreds (maybe thousands) of meters in size on both
| the receive and send points.
| Schroedingersat wrote:
| Just burn the methane when it's cloudy and the batteries
| are flat instead of putting it in a rocket.
| formvoltron wrote:
| zeristor wrote:
| One trick might be to relocate energy intensive industry to
| orbit.
|
| Data centres could be one. Although metal processing,
| transport, and heating seem to be the largest energy consumers.
|
| Of course making anti-matter, and using it as a store of energy
| is a possible option.
|
| Actually antimatter could be trapped in the ionosphere.
| argiopetech wrote:
| grayfaced wrote:
| The article suggests using wide beams for transmission. That
| would mean anyone could passively take power. Without the ability
| to charge for power, isn't it doomed in our economic system? Is
| some municipality going to fund free power for their
| constituents?
| hedora wrote:
| Roads exist. This could be paid for with taxes. Anyway, the way
| the technology works, the entire team target would be filled
| with collector antennas. I imagine they would put a fence
| around that area, if only to protect the receivers from
| wildlife.
| jimnotgym wrote:
| When this is complete, does that mean you win Red Alert 2
| lostlogin wrote:
| I think the company demoing/working with those giants was Emrod.
|
| https://emrod.energy/about/
| patientplatypus wrote:
| Animats wrote:
| > You get 2x - 4x as much sun per unit of panel area. So the cost
| has to be no more than 2x - 4x the cost of ground panels.
| Unlikely.
| akira2501 wrote:
| I don't understand that logic. The difference between the
| ground and orbit is not so great when compared to an entire AU.
| There isn't that much more W/m^2 to be gathered.
|
| The only advantage seems to be, in some imagined
| configurations, you might be able to keep the panel lit close
| to 24 hours a day.
|
| The huge disadvantage that is never mentioned is heat disposal
| under those conditions. If you keep your panel illuminated
| constantly, then how, in a vacuum, are you going to send the
| heat overboard? This article doesn't even try to mention this
| fact.
|
| Particularly when other infographic-heavy publications love to
| point out that with just a small solar farm in the African
| desert, we could power the entire planet. So.. if that's true,
| why are we even _pondering_ orbital power stations? Just to up
| the difficulty by a factor of 100x for gains that are almost
| impossible to achieve commercially?
|
| I get that people are concerned about the climate and are
| willing to do a lot in service of it, but this entire idea is
| absurd.
| philipkglass wrote:
| _The huge disadvantage that is never mentioned is heat
| disposal under those conditions. If you keep your panel
| illuminated constantly, then how, in a vacuum, are you going
| to send the heat overboard?_
|
| The heat has to be radiated away, just as solar assemblies on
| current geosynchronous satellites radiate it away.
|
| "The Solar Array Photovoltaic Assembly For The INSAT 4CR
| Spacecraft: Design, Development And In-Orbit Performance"
|
| https://www.researchgate.net/profile/Sankaran-
| Muthusamy/publ...
|
| Table 1 shows equilibrium solar cell operating temperatures
| in geosynchronous orbit. They're in the range of 49 to 54
| degrees Celsius.
| akira2501 wrote:
| I don't think pondering the performance a satellite bus
| that only provides 3000 watts attached to 4700 lbs of mass
| is a particularly useful comparison here. This proposal
| expects that solar concentrators will be used, and even
| your own data suggests this idea would not be useful
| without them.
| effnorwood wrote:
| yrmhm wrote:
| I keep seeing mention of this, with some projects fairly far
| along and government sponsored, but no one can answer for me how
| they get around the limitations of the Inverse Square Law:
| https://en.wikipedia.org/wiki/Inverse-square_law
|
| Basically, with the distances we're talking about, only a super
| tiny fraction of the energy beamed from space would make it to an
| earth-based receiver. I can't reconcile this basic fundamental
| truth with the fact that these projects actually seem real. Can
| anyone provide insight here? Are these just fanciful proof-of-
| concepts that aren't intended for actual large-scale power
| generation?
| scaredginger wrote:
| You're thinking of the inverse square law the wrong way. What
| it means is that at a distance, d, the power from the source is
| distributed over an area proportional to d^2. Hence, if you
| double distance, your power is distributed over an area 4 times
| as large. However, if your receiver still covers the whole
| area, there is (in theory) no power lost. Ideally, what you
| have is parallel rays transmitting the power, which would imply
| the area doesn't actually increase at all as distance increases
| pgorczak wrote:
| Not trying to argue for the feasibility of space based solar
| power, but the inverse square law applies in the far field i.e.
| when the emitter can be approximated as a point source.
| Depending on the wavelength and the antenna size this is not
| necessarily the case:
| https://en.m.wikipedia.org/wiki/Fraunhofer_distance
|
| E.g. for 3 GHz and a 500 m antenna, the far field starts at
| about 5,000 km
| johnnypangs wrote:
| I found this, seems like it might be similar not sure though:
|
| https://www.quora.com/Does-the-inverse-square-law-apply-to-m...
| johnnypangs wrote:
| This is what I think could be happening from the link:
|
| > That is not the case with the telecom tower, or a
| flashlight, or a laser. In those cases, radiation is
| directed, not equal in every direction. The inverse square
| law still applies, but distance is calculated from an
| apparent source well behind the actual energy source.
| JoeAltmaier wrote:
| Lasers don't work that way.
|
| See, the inverse-square law is about an emitted source
| diminishing because it broadcasts spherically - the surface
| area grows with r^2 because the surface is 2D.
|
| A laser doesn't work that way, nearly. Sure it diminishes, but
| the spread is astronomically (!) small. So for a distance of
| say 24000 miles you can 'beat' the law to a great degree.
| srcnkcl wrote:
| Inverse square law works for light that goes every direction
| like sun or light bulbs, but many of these projects plan to
| send energy directionally like lasers or mirror based solutions
| so the dispersion of light is as minimum as it can get
| netr0ute wrote:
| I don't know if this is how it actually works, but here's my
| hunch. The ISL says that the energy will decrease by 4 (AKA,
| spread out over twice the arc length) for a distance increase
| of 2x. Note that it doesn't specify any actual distance, just a
| ratio. If you concentrated the energy so that the arc length is
| what you want at distance ratio 1, then the ISL doesn't apply
| because you will always be staying at ratio 1 as long as the
| solar system doesn't go any closer or further.
| aetherson wrote:
| You use masers to beam the power down. The inverse square law
| is based on the idea that the power that you send is radiating
| out in all directions (thus, the power experienced at distance
| d from the radiator is based on the surface area of the sphere
| with radius d, thus dominated by a 1/d^2 relationship).
|
| With masers, you aren't radiating out, you're pumping all the
| power in a straight line and you can capture approximately all
| of it by building a capture point as wide as the line.
|
| (More technically, since of course you won't create perfectly
| parallel microwaves, there will _eventually_ be dispersion, but
| it 's not meaningful over the distances that you care about.)
| mlindner wrote:
| Space-based solar power is not a good method of transferring
| power, besides the debris issues that schiffern mentioned, it's
| incredibly inefficient.
|
| Where on Earth do we beam power long distances in any other
| application? If it was a good idea we would be doing it instead
| of running power lines through complex terrain like over
| mountains.
|
| The normal case of efficiency in power beaming is an efficiency
| of only around 40% (if that). At that point any gains you get
| from putting your solar panels in space are immediately lost in
| the transmission to the ground. At which point you've wasted a
| ton of money putting solar panels in space for no gain in energy
| as opposed to building them on the ground.
|
| As far as I'm aware, any attempt at space-based power is some
| segment of scientists misleading politicians for funding grants.
| It doesn't make any technical sense.
| Schroedingersat wrote:
| > Where on Earth do we beam power long distances in any other
| application? If it was a good idea we would be doing it instead
| of running power lines through complex terrain like over
| mountains.
|
| This doesn't necessarily follow.
|
| For example, imagine a 96% efficient magic pixie beam that
| costs exactly as much as 1000km of HVDC transmission line and
| travels in line of sight.
|
| There's no line of sight where it outperforms HVDC, but if you
| could cross 4000km with two hops via space, suddenly it makes
| sense.
|
| SBSP is still a terrible idea though, just not for that
| specific reason.
| thenewthotness wrote:
| The argument for is based on being able to receive 144% of the
| maximum insolation 99% of the time vs ground based which has
| <100% for 40% of the time and 0% for the rest. Clever
| engineering could potentially balance those numbers.
| dtgriscom wrote:
| I couldn't read the article, but I presume it talks about
| transmitting power from space to the ground. My perennial
| question: what technology could transmit massive amounts of power
| that couldn't easily be converted to a weapon? And if these solar
| stations could become space weapons, why would one major country
| allow another to launch and control them?
| DennisP wrote:
| Solar power satellites would be in geosynchronous orbit. Even
| if we wanted a beam tight enough to be used as a weapon, that'd
| be very difficult to achieve. The current designs would have a
| footprint of several square miles. Birds could fly through the
| beam without harm.
|
| And that's with a phased array transmitter that uses a
| reference signal from the ground. If it somehow repoints
| somewhere without the ground transmitter, the beam would spread
| out much more than that. (source: the book _The Case for Space
| Solar Power_ )
| dtgriscom wrote:
| I agree that a "beam of instant death" would be unlikely due
| to the probable low power density. But, couldn't it be high
| enough to cause significant heating and health issues?
|
| As some anecdata, I remember a decades-ago report that said
| it would be safe to graze cattle under the receiving
| antennas, which suggests both that a) it wouldn't be safe for
| cattle above the receiving antennas, and b) it wouldn't be
| safe for humans even under the receiving antennas.
| ben_w wrote:
| Putting them in GEO means that if you have more than 3 in
| total, you have to ask "can a malicious actor make more than
| one beam focus on a chosen target?"
|
| And you do have to care about malicious actors, not just
| accidents, on this scale.
|
| You can only guarantee to avoid this if you put them in lower
| orbits so that no more than one is over anyone's horizon at
| any moment (bonus: saving on antenna mass), and with a phased
| array that's basically fine; but the lower they get, the more
| often they're in Earth's shadow.
|
| (I really need to blog this with pictures, I don't want a
| repeat of last time this came up).
| DennisP wrote:
| Seems pretty clear. That's a decent point.
|
| According to the book, the beam spreads out a lot if you
| don't have the ground signal, but it didn't quantify that.
| And there's always the possibility of some sort of covert
| action putting a transmitter in the target area.
|
| If the malicious actor is hacking the satellites that power
| the victim's country, then the repoint gets a double whammy
| by cutting off power to the areas it was supposed to go.
| credit_guy wrote:
| Space-based solar power will always be a non-starter because
| anything that can beam 1 GW from space is indistinguishable from
| a space-based direct energy weapon.
| IshKebab wrote:
| That's not why it will be a non-starter. It's a non-starter
| because the costs of just transporting solar panels to space
| will always be higher than the costs of the panels. Way higher.
| And that's before you worry about transmitting the power to the
| ground.
|
| This is just another solar roadway. What a waste of time.
| pydry wrote:
| That sounds like the opposite of a non starter.
|
| If it's 20-50% more expensive than a ground based alternative
| Im pretty sure the military would happily cover the difference
| if it made for a good weapon.
| __MatrixMan__ wrote:
| I think the cost goes up in ways not yet accounted for if it
| has to tolerate attempts by the enemy to destroy it.
| credit_guy wrote:
| Yes, but space is shared. You can't just put anything you
| want in space. You preclear all the space launches, else the
| other nuclear powers might take your launch for an ICBM
| launch.
|
| If you put a giant laser fryer in orbit, you can expect China
| to be very unhappy. For example, they could see that any ship
| they plan to send to invade Taiwan could be fried.
|
| Who cares what China thinks, you say? Well, they can put
| nuclear weapons in orbit, what are you going to do about
| that?
|
| Superpowers don't like to gratuitously start the escalation
| game, if they can help it.
| magic_hamster wrote:
| For this to be remotely efficient, transmitting the energy needs
| to be less wasteful than letting the light travel a bit longer to
| the ground. I don't really see how that's possible.
|
| The article mentions current transmissions lose 50% of the
| energy... And that the receiving stations take up a lot of real
| estate. Why not use that real estate for solar panels on the
| ground..?
|
| Even if you could utilize the sunlight 24 hours a day (which is
| not always possible according to the article), perhaps building
| more solar stations on the ground can be distributed so that that
| it's always sunny at all times?
| aaron695 wrote:
| Tade0 wrote:
| My bet is that we'll sooner have HVDC lines going all around the
| planet than this.
|
| There's a wave of projects of this sort like this here:
|
| https://xlinks.co/morocco-uk-power-project/
|
| Which sounds bonkers on the surface, but actually isn't using any
| new, groundbreaking technology(also implementations at half the
| length already exist), so it's projected to be more cost-
| efficient than e.g. Hinkley Point C - a nuclear plant that was
| supposed to produce roughly the same amount of power, but is yet
| to start after all the delays and cost overruns.
| hedora wrote:
| I wonder if it would be cheaper to build floating nuclear
| reactors in international waters, then sink a cable back to
| shore.
|
| The idea isn't to improve safety; instead it would be to avoid
| cost overruns and delays by bypassing regulators.
|
| I suspect it would accidentally improve safety as a side
| effect, but I am a cynic.
| Tade0 wrote:
| > The idea isn't to improve safety; instead it would be to
| avoid cost overruns and delays by bypassing regulators.
|
| From what I've read the issues are usually connected with
| execution - critical components breaking during assembly and
| the like. Also regulations concern mostly safety, so it's not
| like they're there just to be an impediment.
|
| But you generally don't have to go such lengths to bypass
| regulators - just make sure that your plant is hosted by a
| dictatorship.
|
| The Astravyets plant was built on time(5 years!) and within
| budget($11bln). Allegedly there was an accident during
| construction - the concrete housing for the reactor cracked.
| There was also an incident last year which resulted in
| radiation reports from that area being shut down for several
| hours.
|
| But hey, so far there hasn't been any major malfunction.
| formvoltron wrote:
| dyson sphere FTW
| var_cw wrote:
| i think this type of beaming tech would be a prior to dyson
| sphere
|
| dyson sphere still needs a lot of huge engineering upgrades at
| scale
|
| in order to reach there humanity will have go to through series
| of such mega scale projects
| marvindanig wrote:
| yes! solar panels are the gateway drug to mankind's dyson
| sphere.
| formvoltron wrote:
| So many people do not understand this. What do they imagine?
| We'll be flying diesel powered spaceships?
| pfdietz wrote:
| I could see niche markets justifying SBSP, eventually.
|
| One is laser powered aircraft. One could power jet engines
| directly with absorbed laser energy converted to heat, or use PV
| cells tuned to the laser wavelength to convert at higher
| efficiency than cells on sunlight (cooling these would be
| needed.) If this can be made to work the aircraft could have
| unlimited range.
|
| Another possibility is direct exploitation of the beamed power in
| industrial settings without conversion back to electricity. For
| example, laser light might be used in a photochemical process.
| The Toray Process for making caprolactam might be suitable, but
| isn't _that_ large a market; better would be some high mass flow
| scheme like photochemical processing of biomass-derived molecules
| to make fuels. Intense laser light might also be useful for
| heating high temperature furnaces, in place of arc heating. The
| beam could be focused by final reflective optics to high
| intensity.
| moffkalast wrote:
| I don't quite see how you can safely transfer the power from
| orbit to the planet surface (or plane) though. You'll have to
| be shining down a high intensity laser beam that can lens and
| set fire to random things, blind anyone looking at it, etc.
| People go to jail just for pointing laser pointers at
| airplanes.
| pfdietz wrote:
| Perhaps. The laser spot would be moving along with the
| aircraft, sweeping along the ground at hundreds of km/hour
| (you'd use fuel or maybe batteries to get to altitude and to
| land). One might even use a wavelength that would be absorbed
| or scattered in the troposphere, and that would not penetrate
| the eye. Even restricting the system to just be used over
| oceans could be a win.
| moffkalast wrote:
| > sweeping along the ground at hundreds of km/hour
|
| What could possibly go wrong
| DennisP wrote:
| Planet's surface is easy. From geostationary, a microwave
| beam footprint will be several square miles. Birds could fly
| through the beam without harm.
|
| The ground station is mostly antenna wire so it's still not a
| major cost.
| moffkalast wrote:
| Hmm I hadn't considered microwaves, that sounds like it
| would actually be super doable.
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