[HN Gopher] Understanding Solar Energy
___________________________________________________________________
Understanding Solar Energy
Author : chmaynard
Score : 156 points
Date : 2025-03-20 12:09 UTC (10 hours ago)
(HTM) web link (www.construction-physics.com)
(TXT) w3m dump (www.construction-physics.com)
| pfdietz wrote:
| The bit how about incredibly quickly PV has grown is a figurative
| slap in the face to Vaclav Smil. He had just ten years earlier
| said PV wasn't going to grow quickly because historically energy
| replacements took a long time.
|
| https://vaclavsmil.com/wp-content/uploads/2024/10/scientific...
|
| This retrospective on Smil's predictions four years ago is
| notable:
|
| https://www.quora.com/Is-Vaclav-Smil-right-in-his-criticisms...
|
| "To get 1 PWh/year of electricity you need to install about 450
| GW worth of solar panels. You need dozens of years to acomplish
| such task. Reality check: 3 years in current speed, in the future
| probably faster."
|
| Indeed, as the thread top link shows in 2024 the world installed
| 595 GW of PV.
|
| As John Kenneth Galbraith said, "If all else fails, immortality
| can always be assured by spectacular error."
| looofooo0 wrote:
| What people tend to forget is, that coal, oil and gas are all
| restricted by mining or drilling as the old are consumed, and
| it gets harder to access new oil wells etc. For PV there is no
| such limit (only copper basically, but this is recyclable and
| aluminum can do many tasks.) For batteries, there is lithium
| (lifepo4) and even that is questionable (sodium batteries) and
| again there is the potential for recycling. Hence, I do not see
| anything stopping the exponential growth of PV and batteries.
| Ringz wrote:
| You are right.
|
| But one misconception I often read is that everyone focuses
| on batteries. It would make more sense in general to talk
| about energy storage instead of just batteries. Like Kinetic,
| chemical, thermal and so on.
|
| Batteries cannot be solely responsible for back-up. You need
| different types of storage: short term, medium term and long
| term storage.
|
| There are different concepts for each application. Batteries,
| compressed air storage, pumped storage, kinetic, thermal
| storage as well as power-to-X systems are able to absorb the
| increasing summer power and provide the energy again in the
| medium term or seasonally shifted.
|
| https://doi.org/10.3929/ethz-b-000445597
| bryanlarsen wrote:
| There are only three energy storage forms that are relevant
| for the next decade. All the others looked promising, but
| the learning curve on batteries has rendered them
| irrelevant. Your link is from 2020, it is out of date.
|
| The best energy storage form is "final form". Some energy
| products can be stored. For example if you are using the
| energy to create heat, you can store heat for use in the
| future. Heat storage sucks as a way to store energy
| destined for electricity, but is a great way to store
| energy destined for use as heat.
|
| The utility of batteries for daily storage is obvious and
| well proven.
|
| Thirdly, the best annual storage is pumped hydro. It's the
| cheapest and it can be used pretty much everywhere -- all
| you need is water at one end of an elevation change and a
| way to build storage at the other end.
|
| All the other forms that you'd think would fit in between
| the two are being quickly subsumed by the rapid price drops
| in battery pricing. The cutover points are rapidly shifting
| -- batteries are now cheapest for biweekly-ish.
|
| And the primary sources are getting so cheap that
| overbuilding is an alternative to storage. Rather than
| storing for the reduced amount of daylight in the winter,
| just overbuild. More overbuilding and a few days of storage
| will let you handle a stretch of cloudy, windless days in
| January. No annual storage required.
| Ringz wrote:
| Don't get me wrong--I'd be all for batteries ruling the
| world if they were both affordable and technically
| advanced enough to meet various demands. That means they
| shouldn't degrade too quickly, for example, when
| capturing and releasing wind energy in milliseconds. Or
| they shouldn't lose too much energy over time due to
| self-discharge. Or they should be able to supply large
| amounts of energy instantly. Overbuilding is also a valid
| approach, especially in connection with a smart grid
| spanning multiple countries. All of that is fine.
|
| However, the point of the study is different, and that
| makes it still relevant today: The barrier to expanding
| energy storage isn't a technical one--it's a political
| one. The study also shows that there is a great deal of
| variability, and the often-used argument that there's not
| enough lithium or rare earth elements doesn't hold up.
| More recent studies validate different storage
| technologies depending on their specific use case,
| showing that they can complement batteries in a
| meaningful way--also from a financial perspective.
|
| Another perspective is that we still have a long way to
| go before full electrification. Right now, batteries are
| used in suitable scenarios, but many other areas haven't
| been electrified or optimized at all. Other storage
| technologies might still become relevant. Building a
| house around a 20,000-liter tank to store energy for
| heating in Alaska over six months might already be
| financially and technically viable. But whether the
| logistical challenges of such solutions will ever make
| them truly feasible--that's something I neither want nor
| can predict.
| pfdietz wrote:
| > Thirdly, the best annual storage is pumped hydro.
|
| I strongly dispute this. E-fuels like hydrogen would be
| much superior to PHES for annual storage.
|
| https://x.com/iain_staffell/status/1722544993179504965
| Ringz wrote:
| Only if we have more than enough renewable energy to
| spend making hydrogen. Hydrogen storage has a round-trip
| efficiency of 40%-50%, leading to significant energy
| losses. Partly by: Electrolysis requires 50-55 kWh to
| produce 1 kg of hydrogen, which only contains about 40
| kWh, resulting in a 20%-30% energy loss upfront. It's low
| energy density requires high-pressure or cryogenic
| storage, increasing costs and energy use, while leakage
| further reduces efficiency. Limited pipelines and
| refueling stations make hydrogen adoption costly and
| complex. Highly flammable hydrogen demands a lot of
| safety measures adding even more cost and complexity.
| pfdietz wrote:
| At the current exponential growth rate, PV will reach the
| point of supplying the entire world primary energy demand
| in a decade and a half.
|
| Yes, hydrogen has low round trip efficiency. But it comes
| out cheaper than PHES. The "cost of inefficiency" is
| proportional to the number of charge/discharge cycles.
| For annual storage, efficiency is 365x less impactful
| than it is for diurnal storage. What matters for annual
| storage is capex of storage capacity.
| bryanlarsen wrote:
| > What matters for annual storage is capex of storage
| capacity.
|
| Which is exactly why PHES wins the cost comparison for
| annual storage. Open air water storage is ridiculously
| cheap compared to hydrogen storage.
| pfdietz wrote:
| I dispute this as well. From what I see, the very best
| case per kWh cost of just the reservoirs and waterways
| for PHES is about $10/kWh. Hydrogen stored as compressed
| gas in solution mined salt caverns would be an order of
| magnitude cheaper. For storage of liquid e-fuels in
| tanks, tank capex would be another order of magnitude
| cheaper still. This assessment is consistent with the
| link I posted earlier.
|
| If you want something that may compete with hydrogen for
| annual storage, consider bulk thermal storage (using
| artificially injected heat, not naturally occurring
| heat). The thermal time constant of a very large object
| increases quadratically with radius, if everything is
| scaled proportionally, and can easily reach many years.
| This is why geothermal works at all -- there's plenty of
| heat stored in the near crust ready to be mined.
| bryanlarsen wrote:
| You're comparing using an existing reservoir for hydrogen
| to building a new reservoir for PHES. There similarly
| exist dry lake beds that could be used for water storage.
| But generally they're not in suitable locations, which is
| the same problem that salt mines will have.
|
| You're also comparing hypothetical costs to historical
| costs. Hypothetical costs put out by industry are usually
| out by about an order of magnitude.
|
| There's a reason that PHES is the only one with
| historical costs.
| pfdietz wrote:
| No, I was describing the cost of constructing a new
| hydrogen storage reservoir in a salt formation by
| solution mining. Of course existing natural gas storage
| caverns could be repurposed; that would be even cheaper.
|
| These are not hypothetical costs. Construction of these
| caverns is state of the practice for natural gas storage.
| Vast volumes of gas are stored in these things, allowing
| steady production of natural gas and constrained pipeline
| capacity to serve seasonally unsteady consumption
| patterns.
|
| The reason PHES is the only one with historical costs is
| that, historically, PHES has been used for diurnal
| storage, from the days when baseload plants were cheaper.
| There was never a market for long term storage via
| hydrogen (although some hydrogen storage has been
| constructed and used to help steady the hydrogen input to
| ammonia plants); why bother for the grid when just
| varying the use of fossil fuels would serve that function
| just as well?
| derriz wrote:
| > Thirdly, the best annual storage is pumped hydro. It's
| the cheapest and it can be used pretty much everywhere --
| all you need is water at one end of an elevation change
| and a way to build storage at the other end.
|
| Pumped hydro is primarily used for short term storage.
| The vast majority of pumped hydro installations around
| the world operate on an intra-day cycle.
|
| For storage systems generally (not just electricity),
| profitability is a linear function of capacity, the
| possible price arbitrage AND how frequently you charge
| and discharge. Nobody is going to build a pumped hydro
| storage facility with the intension of operating a single
| charge/discharge cycle per year.
|
| Nor are pumped hydro facilities cheap to build and
| certainly cannot be deployed everywhere as they require
| particular geographic and geologic conditions and mostly
| locations suitable for pumped hydro are few and far
| between and those locations that are suitable are
| generally far away from population centers where the
| demand for electricity is.
|
| Batteries are often cheaper than pumped hydro, they can
| be located near demand, they scaled down as well as up
| and can be distributed around the grid to provide
| "virtual transmission". They are quick to deploy and
| require little maintenance or staffing.
|
| The solution for "long term" storage will be massive
| over-provision of wind and solar and more grid
| interconnections. Batteries will take care of everything
| else.
| pjc50 wrote:
| I think this is going to turn out like the exotic panel
| chemistries: batteries are simple and have powerful
| continual improvement in performance and price, while the
| others turn out to be more complicated. In particular solid
| state wins over mechanical anything almost every time.
| Ringz wrote:
| I am on you side (but not all are more complicated and
| there are mechanical variations that are better than
| batteries for some scenarios) but the takeaway of that
| study is described here:
| https://news.ycombinator.com/item?id=43425560
| pfdietz wrote:
| PV doesn't require much copper, either. Maybe for front
| contact wires, if silver gets too expensive? But if it can
| afford to use silver now, copper won't be a huge ask
| (basically just need to deposit a barrier layer to keep the
| copper from reacting with the silicon.)
|
| The cables connecting PV to the grid, as well as the grid
| itself, can all use aluminum conductors. Even large
| transformers can be designed with aluminum if copper gets too
| expensive.
| Ringz wrote:
| The IPCC & IEA grossly underestimates PV (and Wind) by any
| metric for years. Many scenarios assumed costs for 2050 that
| are already outdated today.
|
| In the same time they overestimate Nuclear Energy and carbon
| capture by any metric (debatable). It's getting so bad that
| there are numerous studies about that problem.
|
| https://www.carbonbrief.org/guest-post-why-solar-keeps-being...
|
| https://www.pv-magazine.com/2021/03/31/solar-still-largely-u...
|
| https://www.theenergymix.com/leading-climate-models-underest...
|
| https://climatenexus.org/climate-change-news/iea-historicall...
| epistasis wrote:
| I think a lot this comes down to huge cultural biases. And
| the two cultures are "hard energy" and "soft energy" folks.
| Coal, gas, fission, fusion, etc. are all hard energy. Coupled
| GDP and energy consumption was a core assumption. Renewables,
| energy efficiency, technological advancement via learning
| curves all fall under "soft energy".
|
| Most of the energy industry was hard energy because that's
| what paid everyone's bills. Any estimates that did not cater
| at least a bit to those biases would just be completely
| ignored.
|
| But there's another effect too: solar just completely
| outperforms even the most optimistic assessments. There's one
| famous solar financial analyst, whose name I'm blanking on,
| who continues to underestimate even though she knows the
| effect.
| pfdietz wrote:
| It was also underestimation of China. Outright chauvinism
| there.
| Ringz wrote:
| iCal them ,,simple" and ,,complex" power. For someone who
| isn't truly informed, a ,,Simple Energy" solution seems
| much simpler than one based on renewable energy. With
| ,,simple" power, solving climate change appears
| straightforward: just build more nuclear plants, which
| conveniently replace coal and gas on a 1:1 basis since they
| are baseload power generators.
|
| Renewable energy, on the other hand, is (for now, the
| transition time) complex. It requires a better, smarter,
| and much larger interconnected grid, as well as intelligent
| management of supply, demand, and storage. It means
| considering and understanding multiple aspects at once.
| This complexity often leads people who are convinced that
| more simple power is the answer to dismiss the idea of
| renewables too quickly--because nuclear seems so much
| simpler.
|
| I understand the appeal of simple energy. The sad part is
| that many people likely believe this is the scientifically
| correct position. And they are often so convinced that,
| even when presented with current studies and reasonable
| arguments against new nuclear plants, they quickly assume
| that the other person is just an irrational, biased anti-
| nuclear activist. After all, the simplest solution must
| also be the right one, right?
|
| Being informed in this context doesn't just mean knowing
| the pros and cons of nuclear, wind, or solar power. It
| requires a deep understanding of what is technically and
| financially feasible today--including energy forms, grid
| transformation, storage solutions (not just lithium-ion
| batteries), follow-up costs, sustainability (mining, waste
| disposal), as well as political, economic, military, and
| social implications. And how all of these factors interact.
|
| But none of that is necessary if you just want to build
| more simple power plants.
|
| The transition to 100% renewable energy is as complex as
| the development of the internet. If we were still relying
| on letters, telephones, fax machines, newspapers, radio,
| and TV, the idea of transitioning to a globally available,
| instant multimedia internet would have seemed just as
| utopian and impossible.
| ZeroGravitas wrote:
| Jenny Chase perhaps:
|
| > On Friday my colleagues suggested I get a tattoo reading
| "COWARDS", to save me time saying it in solar forecast
| calibration meetings.
| epistasis wrote:
| That's her! She's done really amazing work for
| BloombergNEF.
| jillesvangurp wrote:
| There is a lot of stuff that people said about this solar that
| got overtaken by reality. And some of those people were
| proponents even.
|
| People have underestimated economics, learning effects, and the
| effects of increased scale. Mostly the exponentials were
| actually pretty clear to some investors as early as 15 years
| ago. And the success those investors have had, has driven more
| investment.
|
| The thing with exponential trends is that doubling a little bit
| results in a little bit more. It doesn't add up to something
| people notice until suddenly it jumps from fractions of a
| percent, to full percents, to double digit percentages in the
| space of a few years. That threshold got crossed a few years
| ago and people started to notice. And that's now leading to
| further price drops and more adoption. Of course, it's not a
| real exponential but an s-curve. But until the curve flattens,
| you won't be able to tell the difference.
|
| Back of the envelope calculations can be misleading because
| they tend over simplify and make silly assumptions. Like
| assuming we are going to move 100% of energy to solar all at
| once. In reality, what we're doing is a decades long transition
| where most of the decision making is cost driven and the energy
| supply is coming from mixed sources.
|
| We don't have just solar. We have existing nuclear. Existing
| deployments of coal and gas, which like them or not are not
| going to disappear overnight. And a lot of onshore and offshore
| wind. And a rapidly growing amount of batteries and cables
| which give us the ability to time shift supply and demand and
| move energy around over large distances.
|
| The world's electricity consumption is about 30 PWh per year
| and will probably grow to 35 or 40 soonish. Most of that growth
| (>90%) will be powered by renewables. It's outgrowing
| everything else by a large margin. And because they are
| cheaper, there is also pressure to replace existing generation
| with renewables. That basically happens based on cost and age
| of plants.
|
| This is another effect that people keep underestimating. The
| reason coal generation is rapidly disappearing from many
| markets (and is completely gone in some of them) is that
| replacing them with cheap renewables is cheaper than continuing
| to operate them.
|
| That same effect is going to affect gas generation. Anyone
| building gas plants with the expectation that they'll have a 60
| year life span is dreaming at this point. These investments
| should be considered as under water at this point. By the
| 2050s, most currently new gas plants will have probably have
| been mothballed (maybe kept around as rarely used peaker
| plants) or demolished. They are simply too expensive to operate
| relative to renewables. Some places keep gas prices low via
| subsidies (the US for example). But even there gas plants are
| going to face a reality check. And for a lot of countries, gas
| imports are a drag on their economy. Germany is a good example.
|
| Worth observing what investors do here. They tend to have long
| term outlooks.
| ZeroGravitas wrote:
| Smil was just bullshitting though, really poor quality
| arguments made for rhetorical effect with a side helping of
| smug fake reasonableness.
|
| He's a cranky old academic propelled to fame because he said
| what the establishment wanted to hear like an energy Jordan
| Peterson.
| pjc50 wrote:
| Good longread.
|
| What I'd like to have a better understanding of, and I'm hoping
| to crowdsource here, is exactly how the solar panel cost has come
| down so precipitously. Part of it is simply manufacture scaling -
| almost everything is much cheaper in large quantities. But part
| of it must be a thousand incremental tech advances. Things like
| the reduced kerf diamond wire saw.
|
| Also of note: I think monocrystalline has won completely? People
| experimented with all sorts of alternate chemistries and
| technologies, like ion deposition and the extremely poisonous
| CIGS, but good old "Czochralski process + slice thinly" has won
| despite being energy intensive itself.
|
| Perovskites remain an unknown quantity.
| pfdietz wrote:
| CdTe is still out there, from First Solar, but it's not much of
| the market (and has scalability problems due to the need for
| tellurium, even if the active layer is much thinner than in
| silicon cells.)
|
| One little advance that swept the industry a couple of years
| ago was replacement of boron as a dopant by gallium. Boron
| doped silicon has light induced degradation, which was
| determined to cause a small loss in efficiency due to formation
| of boron trapping centers under prolonged light exposure.
| Gallium-doped silicon doesn't have this problem.
| wolfram74 wrote:
| You're in luck! The author's earlier piece on the subject
| attempts to address that exact question. Learning curve effects
| and piggy backing off the computer chip industry are major
| factors if I recall, but I haven't reread the piece in a while.
|
| https://www.construction-physics.com/p/how-did-solar-power-g...
| doctoboggan wrote:
| My understanding is that China recognized the potential of
| solar power around 20 years ago and decided they wanted to be
| the world's manufacturing hub for solar panels. The government
| invested in R&D early, and today we are reaping the fruits of
| that investment.
|
| The same thing is happening now with storage, but western
| governments are weary of losing that battle as well. To address
| this massive tariffs were put in place by the previous US
| administration, and are likely to be increased by the current
| administration. Hopefully this doesn't slow down the production
| of batteries, but instead just moves the production out of
| China and into other countries, but that remains to be seen.
| cman1444 wrote:
| Wary not weary
| philipkglass wrote:
| The article posted by wolfram74 is part one of two, covering
| solar PV history up through the early 1980s.
|
| Here's part two of the series with more recent history:
| https://www.construction-physics.com/p/how-did-solar-power-g...
|
| Even this fairly long two-part discussion misses some of the
| more important technical developments of the past 20 years.
|
| Converting trichlorosilane to pure silicon via CVD growth in
| Siemens-type reactors is now much more energy efficient due to
| changes in rod geometry and heat trapping via reactor design. A
| significant minority of purified silicon is now manufactured
| via even more efficient fluidized bed reactors.
|
| The solar industry is dominated by Czochralski process
| monocrystalline silicon, but it's now _continuous_ Czochralski:
| multiple crystals grown from a single crucible, recharging the
| molten silicon over time; the traditional process used a
| crucible once and then discarded it.
|
| The dominant silicon material has switched from boron doped
| p-type silicon to gallium doped p-type silicon (mentioned by
| pfdietz) to phosphorus doped n-type silicon (used by the
| currently dominant TOPCon cell technology as well as
| heterojunction (HJT) cells and most back contact cells).
|
| Changes in wafering that you mentioned (like the reduced kerf
| diamond wire saw) have reduced silicon consumption per wafer
| and therefore per watt, even holding cell technology constant.
|
| The dominant cell technology has moved from Al-BSF to PERC to
| mono-PERC to TOPCon. Heterojunction and back-contact cells are
| not yet dominant, but they are manufactured on a multi-gigawatt
| scale and will probably overtake TOPCon eventually. Each one of
| these changes has eked out more light conversion efficiency
| from the same area of silicon.
|
| Cells mostly still use screen-printed contacts made from
| conductive silver pastes, much like 20 years ago, but there has
| been continuous evolution of the geometry and composition of
| applied pastes so that silver consumption per watt is now much
| lower than it used to be. This is important because silver has
| the highest cost per kilogram of any material in a typical
| solar panel, and it's the bottleneck material for plans to
| expand manufacturing past the terawatt scale.
|
| Wafer, cell, and module manufacturing have become much more
| automated. That reduced labor costs, increased throughput, and
| increased uniformity.
| justanotherjoe wrote:
| In terms of resource extraction needed for the batteries and
| the panels, how sustainable is it? The way I understand it is
| that you can't really repair broken panels and batteries...
| Can we still make these after, let's say, 500 years? I have
| no conception at all in this topic...
| pjc50 wrote:
| No, but I don't see a good reason why you can't recycle the
| cells especially given they contain a thin layer of silver.
| Google already finds local recycling firms, since it's
| required by WEEE.
|
| (The 500 years question has issues for all the other
| sources of energy as well!)
| ZeroGravitas wrote:
| Yes, batteries are getting better at such a rate that you
| can recycle old batteries at end of life, lose 10% of the
| material in that process and build a new battery with new
| tech and less material that is better than the original.
|
| The resource extraction issue is more than these are so
| useful we're going to build an ever growing amount of them.
|
| Luckily they're made from widely available materials, with
| even more widely available substitutions possible e.g
| sodium batteries.
| angleofrepose wrote:
| Thank you and other commenters for the great rundowns here.
| I'm interested in a related question and I wonder if you or
| others could point me in the right direction: why was the
| mainstream consensus around solar power (and/or batteries)
| apparently so wrong for so long? More specifically -- and
| maybe a better question -- why didn't progress in solar and
| batteries happen sooner?
|
| I'm less interested in blame than in a systems analysis of
| how in the last half century powerful players seem to have
| missed the opportunity to start earlier investment in solar
| and battery technology. Solar and batteries are unique in
| energy infrastructure, as even any casual observer knows by
| now, and is certain to change many aspects of politics,
| industry and culture. It seems an inevitability that energy
| infrastructure will evolve from large complex components
| towards small and simple components, and I'm interested in
| engaging with the history of why "now" is the moment, rather
| than decades ago.
| mjamesaustin wrote:
| It's a false assumption that technological progress happens
| automatically or even that it's based upon the passage of
| time.
|
| Progress happens as a result of many choices made by
| individuals to invest time and energy solving problems. Why
| is solar rapidly improving now? Because way more people are
| invested in making it better.
|
| Nascent technologies almost always face an uphill battle
| because they compete against extremely optimized legacy
| technologies while themselves having no optimization at
| first. We only get to the current rapid period of growth
| because enough people pushed us through the early part of
| the S curve.
| angleofrepose wrote:
| Sure, that makes sense. This is where I'm coming from
| with my interest in history:
|
| I heard an interesting argument somewhere that solar
| cells are an ideal manufactured good. Whether you are
| building a module for a calculator or a GW scale plant,
| the modules are the same. This is fundamentally different
| for steam turbines. On the "concrete-internal combustion
| engine" spectrum of complexity, solar modules are closer
| to concrete and turbines are closer to ICEs.
|
| Shouldn't this have led to a special interest in
| advancing solar module research? Or widespread
| understanding that eventually the unique set of
| attributes that define a solar module would lead to it's
| takeover of a significant portion of global energy
| generation? Shouldn't that have been apparent from the
| earliest days of photovoltaic research as a sort of
| philosophical truth before the advances in material
| science, extraction or manufacturing of the last fifty
| years?
| epistasis wrote:
| Solar and batteries got cheaper when we scaled up and built
| a lot. You have to pay current prices to get the next price
| drop, because it's all learning by doing.
|
| If we had pushed harder in the 80s, 90s, and 2000s, solar
| might have gotten cheaper sooner. Solar fit in at the edges
| of the market as it grew: remote locations for power, or
| small scale settings where running a wire is inconvenient
| or impractical. The really big push that put solar over the
| edge was Germany's energiwende public policy that
| encouraged deploying a ton of solar in a country with
| exceptionally poor solar resources; but even with that
| promise of a market, massive scale up was guaranteed.
|
| It's in many ways a collective action problem. Even in
| _this thread_ , in 2025 you will see people wondering when
| we will have effective battery technology, because they
| have been misinformed for so long that batteries are
| ineffective that they don't see the evidence even in the
| linked article.
|
| Also, most people do not understand technology learning
| curves, and how exponential growth changes things. Even in
| Silicon Valley, where the religion of the singularity is
| prevalent and where everyone is familiar with Moore's law,
| the propaganda against solar and batteries has been so
| strong that many do not realize the tech curves that solar
| and batteries enjoy.
|
| A lot of this comes down to who has the money to spend on
| public influence too, which is largely the fossil fuel
| industry, who spends massive amounts on both politicians
| and in setting up a favorable information environment in
| the media. Solar and batteries are finally getting
| significant revenues, but they have been focused more on
| execution than on buying politics and buying media. They
| have benefited from environmental advocates that want to
| decarbonize, without a doubt, but that doesn't have the
| same effect as a very targeted media propaganda campaign
| that results in zealots that, whenever they see an article
| about climate change, call up their local paper and chew
| out the management with screaming. Much of the media is
| very afraid of right wing nuts on the matter and it puts a
| huge tilt on the coverage in the mass media in favor of
| fossil fuels and against climate science.
| angleofrepose wrote:
| Indeed. You widen the conversation here, and remind me of
| the idea that moneyed influence is underrepresented in
| analysis and understanding of the world. Maybe the most
| appropriate way to understand big questions is who is
| funding the various players.
|
| I like to think about "learn by doing". While I have of
| course lived it, I try to think of counterpoints. It
| seems clear that solar owes it's growth to Germany and
| California policies which subsidized the global solar
| industry with taxes on their economies, most
| disproportionately placed on individual ratepayers. But
| why couldn't solar research have been long-term funded
| based on it's fundamental value? Talk about national
| security, or geopolitical stability -- especially post
| 1970s! Skip the intermediate and expensive buildouts of
| the 2000s, failed companies heavily subsidized and fund
| research instead to hopefully bring the late 2010s
| forward in time?
|
| What's a good model here, or concrete example? We see the
| same side of the history in electric vehicles. I think
| Tesla and Rivian, to pick two, both lost money on every
| sale in early years. Why not skip that expensive step in
| company history, and develop better products to sell at a
| profit from the beginning of mass manufacturing? Are
| there industries or technologies where this
| expensive/slow process went the other way?
| epistasis wrote:
| > It seems clear that solar owes it's growth to Germany
| and California policies which subsidized the global solar
| industry with taxes on their economies, most
| disproportionately placed on individual ratepayers. But
| why couldn't solar research have been long-term funded
| based on it's fundamental value
|
| I think this is a really important distinction, that
| between research in the lab versus research on the
| factory floor. Tesla in particular has talked about how
| much they value engineers that get down in to the
| production process versus those that are working in the
| lab. That's the "doing" that needs to happen. As well as
| shaking out parts of the upstream supply chains and
| making all that cheaper.
|
| We can theorize about what's going to work in practice,
| but the price drops are the combination of 1% savings
| here, 0.75% savings there, 0.5% there, and until you have
| the full factory going you won't be able to fully
| estimate your actual numbers, much less come up with all
| the sequential small improvements that build on each
| other. And all that comes together in the design of the
| next factory that's the next magnitude up in size.
| angleofrepose wrote:
| I hear that, it seems a common observation. Maybe a
| fundamental truth of enterprise.
|
| > until you have the full factory going you won't be able
| to fully estimate your actual numbers, much less come up
| with all the sequential small improvements that build on
| each other.
|
| Why not? Is there a theory or school of management or
| industry that establishes this foundational principle
| that seems so commonly invoked? It feels true, but I
| don't really know why it might be true. There must also
| be great examples of counterpoints in this too!
|
| Maybe it goes back to learn by doing: it's a common
| refrain in outdoor recreation that safety rules are
| written in blood; that many of our guidelines directly
| follow from bad things that happened. But certainly we
| can also design safety rules by thinking critically about
| our activities. Learn by doing vs theory.
| dgacmu wrote:
| It's literally studied as "learning" in the management
| science literature.
|
| For example: https://pubsonline.informs.org/doi/abs/10.12
| 87/mnsc.2015.235...
|
| > We find that productivity improves when multiple
| generations of the firm's primary product family are
| produced concurrently, reflecting the firm's ability to
| augment and transfer knowledge from older to newer
| product generations.
| pjc50 wrote:
| > why didn't progress in solar and batteries happen sooner?
|
| The rate of progress in cost reduction has been
| astonishing. It's unlike anything except Moore's Law. This
| catches people out.
|
| As well as the usual suspects: cheap fossil fuels, failure
| to take global warming seriously, belief that nuclear power
| _would_ see similar exponential cost reduction rather than
| opposite, and of course anti green politics.
|
| But if 95% cost reduction is the result of not taking it
| seriously, would taking it seriously earlier have been even
| better? Hard to say.
| angleofrepose wrote:
| Right! Good points for optimism here, and acknowledging
| broken mental models.
|
| We have silicon solar modules in the 1950s, Moore's law
| in the 1960s. Another take on the question then: today we
| use Moore's law to describe progress in solar modules, to
| what extent was that realization possible in the 1960s
| from the fundamentals, or "first principles"?
|
| If it was clear, why did we not see rapid prioritization
| of solar and energy storage technology research? Or did
| we and I don't know the actual history? Or what
| influences am I undervaluing or not recognizing?
|
| If it wasn't clear, why not? Gaming out many positive
| impacts of solar technology feels easy today in a way it
| appears was not easy in the past. Why wasn't it clear in
| the past?
| bryanlarsen wrote:
| Great article. Unfortunately his California duck curve graph only
| shows 2023. A graph including 2024 shows how batteries are
| dramatically flattening the duck curve:
|
| https://cdn-ilcjnih.nitrocdn.com/BVTDJPZTUnfCKRkDQJDEvQcUwtA...
|
| https://reneweconomy.com.au/battery-storage-is-dramatically-...
| epistasis wrote:
| And similarly the battery prices are very outdated. I don't
| blame the author for using those estimates, I frequently do too
| just because getting access to current data usually requires
| paying money.
|
| But making decisions on that data without understanding that
| current prices and near-term prices will be about half of that
| price will lead to bad decisions. And when thinking 5-10 years
| out, not taking the full exponential drop in battery and solar
| prices is beyond foolish.
| r00fus wrote:
| Actual battery prices may be dropping but cost to install
| batteries to your solar installation in CA have not dropped -
| in fact they've gone up.
|
| Not sure why this is the case.
| epistasis wrote:
| This is by design in the regulatory infrastructure, from
| local permitting offices all the way up to CPUC and rate
| structures.
|
| We pay about $3/W for solar installation in the US, but
| Australia pays about $1/W.
|
| For batteries, there's still a supply crunch and the only
| people getting really good prices are those people who buy
| in huge bulk or are willing to take a risk on a lesser
| known manufacturer. If you want well-proven brands the
| prices can still be very high for small purchases, and a
| solar installer is not going to want to take a risk with a
| new supplier.
|
| These systems are not super complex, most technical people
| could figure them out fairly easily, and in fact off-grid
| disconnected systems are _really_ easy to do. It 's the
| grid tie that will kill you or first responders to your
| house, we have made the process of setting the whole thing
| up very expensive because nobody on the regulatory side has
| an incentive to make it straightforward and cheap. And
| since NEM3 killed solar in California, all the installers
| are barely scraping by and need to rely on very high
| margins on few projects.
| PaulDavisThe1st wrote:
| > This is by design in the regulatory infrastructure
|
| I don't see how this can be true. I installed my own
| ground mount array, and the costs directly attributable
| to regulatory infrastructure were about US$35 (for the
| permit). It would have been no higher if I had added
| batteries. The material costs were completely comparable
| with AU, CAN and UK pricing.
|
| Perhaps you're arguing that the certification and
| licensing regulations for paid installers drives the
| installation cost up (i.e. that labor costs for US solar
| installs are too expensive) ?
| epistasis wrote:
| > and the costs directly attributable to regulatory
| infrastructure were about US$35 (for the permit)
|
| That may be true if your time is free, but for a company,
| they must deal with a permitting scheme for every county
| and city that they do business in. Additionally,
| unpredictable changes to rate structures will drastically
| change the demand for solar in areas year to year, and so
| the solar installers that survive are the ones who are
| well attuned to that change, and pounce on new markets
| that are suddenly opened up by new rate structures that
| make solar easy to finance or pay off quickly. That means
| that about $1/W of the $3/W that installers charge
| actually goes to customer acquisition costs.
|
| Most areas do not have super onerous labor requirements
| for solar installers, and generally the contractor
| licensing part is quite reasonable. But perhaps insurance
| like workers comp and disability is a lot higher in the
| US than in Australia.
|
| I'm surprised that US tariffs have not resulted in higher
| materials costs than in the other anglophone countries!
| PaulDavisThe1st wrote:
| I installed my system 5 years ago, when no particularly
| unusual tariff structure was in place.
|
| Your reply seems to indicate that "regulatory
| infrastructure" is not responsible for the bulk of the
| cost, but rather traditional concerns of for-profit
| business, in this case, the business of solar PV
| installation.
| Calwestjobs wrote:
| Hot water tank heated by electricity and powering on at noon is
| flattening curve. You can say hot water tanks are cheapest,
| simplest and fastest deployed energy storage device.
|
| Solar + hot water tank can provide any house in US with 100%
| solar hot water (from PV!) for 80% of time, remaining 20 % of
| time you can have 10-99% solar heated water.
|
| So we should focus on saying to people that if they buy solar
| and add electric heating element to hot water tank, then PV
| system will pay itself much sooner and their batteries will
| last longer. Becasue it is known and predictable load, you need
| hot water every day. And hot water is order of magnitude more
| energy then TV, lighting...
|
| By lowering household usage like this we can make energy
| transition faster, cheaper.
|
| Also proper construction - house heated only 10 days in a year
| - https://www.youtube.com/watch?v=5KHScgjTJtE
| opwieurposiu wrote:
| I installed PV solar hot water at my house, works great.
| Makes about $2 a day worth of power.
| Calwestjobs wrote:
| Congrats, using as much energy directly on site is crucial
| for fast and cheap energy transition of economy.
| epistasis wrote:
| Converting a gas water heater to electric and/or solar is one
| of the best bang for the buck on decarbonization too.
| Something that should be done before buying an electric car
| or swapping out your gas furnace for a heat pump. Though I'm
| terrible at following my own advice, I still have a gas water
| heater, just because I needed to replace my car and furnace
| before I needed to replace my water heater. That said, the
| sunk cost fallacy applies to carbon emissions just as hard as
| it does to dollars so I have little excuse for not replacing
| it except laziness (and space on the breaker panel...)
| ipdashc wrote:
| Is it a fallacy though? It doesn't make sense to buy a new
| EV if you still have a gas car that's working fine. In the
| same vein, I wouldn't want to throw out my gas furnace or
| water heater to replace with electric, creating waste and
| requiring the manufacturing of a new unit
| bryanlarsen wrote:
| That only applies if you're only going to get less than 1
| year of use out of a heat pump. A heat pump has an
| "embodied CO2" of 1.7t, which is about the same as the
| annual CO2 emissions of a gas furnace.
| epistasis wrote:
| Can you explain how it's not a fallacy? Compare your
| lifetime emissions of replacing a gas car with an EV now
| versus at the "end of life" of the gas car. Emissions
| will _always_ be lower if you replace now rather than
| later.
|
| Imagine if _everybody_ switched to EVs right now, en
| masse. Emissions over the next decade, and every
| subsequent decade, would be massively lower. Waiting for
| every gas car to reach end of life before switching is
| always going to be higher emissions, always.
|
| Similarly, the "waste" already happened when the gas
| heater was manufactured. There's no additional waste when
| it's decommissioned. It's a sunk cost, there's no getting
| that back. The only question is if you switch to lower
| emissions now, or you switch to lower emissions later.
|
| Now, if you bring money into it, sure, there could be a
| financial motivation to keep emitting higher amounts of
| emissions. But if you take monetary considerations out of
| it, it's _always_ better to stop emitting sooner rather
| than later.
|
| I'd love to have some serious push back against this. The
| best I've ever got is "that doesn't sound right..."
| without any engagement with the quantitation or the
| ideas. Which is exactly what I would expect if it was a
| fallacy.
| Retric wrote:
| You're incorrect, buying a new EV when you have an ICE
| car doesn't actually destroy the ICE vehicle.
|
| There's a bunch of different possibilities to consider,
| but if you drive more than the average person buying an
| EV and selling your ICE is great for the environment. If
| you rarely drive then keeping an old ICE car out of the
| hands of a frequent driver has real value etc.
|
| As to the environmental impact vs retrofitting an ICE
| vehicle into an EV, the grid has gotten a lot cleaner
| over time so many of the old assumptions around EV's are
| outdated. Comparing the emissions from extracting,
| transporting, refining, and then burning gas vs the same
| with EV's built with a cleaner grid and more electrified
| infrastructure now heavy favors EV's. And these
| calculations just keep favoring EV's more every year.
| opwieurposiu wrote:
| If you want to DIY a solar PV water heater I made a whole
| website about it with instructions and a simulator to
| estimate what your payback period could be.
|
| https://www.pvh2o.com/
| PaulDavisThe1st wrote:
| Resistance heating is so 20th century. Granted, you
| likely cannot do a DIY air source heat pump build, but
| the COP is so high for such systems, that it's probably
| worth it to just buy it.
| opwieurposiu wrote:
| My mom had a Heat Pump water heater at her house and I
| was always having to go and fix it or clean the filter.
| It would start beeping loudly in the middle of the night
| when it wanted attention. The hot water was frequently
| not very hot.
|
| Hopefully the new heat pump water heaters are better. The
| advantage of resistance heating is simplicity and cost,
| with no moving parts. Solar panels are so cheap now they
| make it hard to justify the expense of the heat pump,
| assuming you have room to mount the panels.
| PaulDavisThe1st wrote:
| a COP of 4 can certainly justify having to install 3-4x
| less panels.
|
| it disappoints me (but thrills me) that improvements in
| PV efficiency and cost have made solar thermal hot water
| more or less pointless.
| MostlyStable wrote:
| Slightly less convenient/has more impact on how we percieve
| our environment, but HVAC (the number 1 power use, hot water
| is #2), can also be a decently good battery, if your house is
| well insulated. Where I live, power is incredibly cheap over
| night, so I over-heat or over-cool my house (depending on
| season) overnight, and then let it gradually equilibrate
| during the day.
|
| I realize that some people won't be willing to have a very
| warm/very cold house that gradually shifts to the more ideal
| comfortable range, but for people who are willing to deal
| with that (it personally doesn't bother me), it's a pretty
| easy way to shift a lot of power use and, if you have Solar
| or Time of Use billing, save a lot of money.
| Calwestjobs wrote:
| Yeah that too, but that has limits, for example european
| union regulates building industry in such way that every
| new build, rebuild has to be done in a way that your
| heating energy requirement is already lower than your hot
| water energy requirement. Because hot water energy usage
| can not go lower in current society, but buildings can be
| improved a lot. So yes as you said if building is modeled
| in software tools like OpenStudio ( Revit, archicad uses
| this sw developed in collaboration by NREL, ANL, LBNL,
| ORNL, and PNNL ) before build, to make building not waste
| energy and capture as much sun in cold period as possible
| then even such strategies can be used. You can not preheat/
| precool 1870s handhewn cabin, all energy will be lost very
| fast. It sounds obvious to you and me but most people do
| not really understand this deeply enough to "click" in
| their heads.
|
| time of use billing - tool to incentivie you to use "off-
| peak" power, but i guess it will be deprecated in favor of
| "realtime" billing in future, because there will be so much
| solar (almost zero $ per kWh on market) that your energy
| provider will incentivize you to draw energy during peak
| solar "activity" AND off-peak hours. it will be simpler for
| them to give you market price every 15 minutes window than
| 4hour window at same time every day.
| andbberger wrote:
| has PV finally overtaken solar hot water?
| Calwestjobs wrote:
| well just piping for hot water system is more expensive
| then PV panels.
|
| But biggest expense is instalation costs(humans) so it
| depends how you calculate. But PV system can be used for
| hot water, tv, car, charging kids bikes, lawnmower etc.
| Solar thermal can be used only for hot water (or cooling if
| you use multistage heat pump but that is viable only in
| office buildings or hockey stadiums and such).
| megaman821 wrote:
| Using a hot water tank as a battery is an incredibly simple
| idea. I wonder how much electric hot water heaters on a timer
| could flatten California's duck curve.
| ok_dad wrote:
| There's a company doing that in Hawaii, I think it's called
| "shift energy". I interviewed with them, it seemed like a
| great operation, but a bit hobbled by being a startup in
| Hawaii. I respect it though, I'd do the same.
| dzhiurgis wrote:
| My hot water heats up in less than 2 hours and if I don't
| fire it up at night I won't have hot water in morning.
|
| At this point getting some batteries would likely be cheaper
| than new boiler + plumber to install it.
| PaulDavisThe1st wrote:
| It loses heat overnight, or you use all the hot water
| contents overnight?
| ZeroGravitas wrote:
| They also use the duck curve to represent energy demand, when
| it only reflects grid demand minus utility solar and wind.
|
| There's nothing particularly confusing about the duck curve but
| it must be the most misunderstood (and/or misrepresented) graph
| in all energy.
| losvedir wrote:
| This is a great summary of the situation. I've been thinking
| about installing solar panels on my house, and been thinking
| about these same sorts of issues. Unfortunately, for my situation
| here near Chicago, things are much worse than the author's
| Atlanta: winter requires _tons_ of energy here because it 's very
| cold, and we have even less sun then.
|
| It's one of the things that makes me think about wanting to move
| to Texas or Phoenix or something. Ample year round sun, and the
| big energy expense: climate control, corresponds much better to
| when you have it (you need to "cool" in the summer and the day).
| It rubs me the wrong way that here, our big energy cost is
| heating in the winter. It doesn't fit well with the utopian solar
| future I'm envisioning.
| danans wrote:
| Assuming you would stay in Chicago for other reasons, the
| solution for a high heating bill is 1) air seal and upgrade
| insulation in your house, and then 2) replace your furnace with
| a low temperature heat pump.
|
| Chicago has electricity prices 25% lower than the national
| average. If you want to see an example in your area, watch
| Technology Connections heat pump videos on YouTube.
| bityard wrote:
| Air seal and upgrading insulation: correct me if I'm wrong,
| but that implies either tearing open all of the exterior
| walls or ripping off all of the siding, no? If so, it feels
| like it would take a LONG time to recoup the cost of
| materials and labor for that job, unless there was literally
| no insulation in there to begin with.
|
| Alex is a smart guy, and he makes a lot of convincing
| agruments in favor of heat pumps, but the thing he
| consistently sweeps under the rug is that for about half the
| US (and all of Canada), the annual cost to run a heat pump
| sits well between a natural gas furnace and resistive
| heating. And the further north you go, the more it shifts to
| the right. I run the numbers every few years and for my
| specific house, I'd pay 30% more to run a heat pump instead
| of a furnace. (Before factoring in the cost of the unit
| itself and installation labor.)
|
| Where I live, the only way heat pumps make economical sense
| is if natural gas gets dramatically more expensive, or if
| solar gets cheap enough that every household can afford a
| roof full of solar panels and a basement full of batteries.
| (Which to be honest is kinda my dream situation anyway.)
| doctoboggan wrote:
| I second the other reply. I live in Chicago and installed an
| air source heat pump. (Mitsubishi hyper heat). Its served me
| well for two winters so far. My next step is probably to
| replace all my windows and doors to get better efficiency.
| 1970-01-01 wrote:
| I mentioned this yesterday, but storage is the new holy grail for
| cheap energy. If humans could focus on building safe and reliable
| battery tech instead of AI and bitcoin, we will have solved the
| energy crisis until fusion is ready.
| Ringz wrote:
| There are studies (at the bottom of my post:
| https://news.ycombinator.com/item?id=43424310) showing that
| storage is mostly a political issue.
| epistasis wrote:
| We already have safe and reliable battery tech being deployed
| in massive amounts as is in plentiful evidence in this article.
|
| Solar with IRA subsidies is $30/MWh in the US, without
| subsidies it's $50/MWh. Current storage prices are probably no
| more than $60-$70/MWh for storing solar for later. New natural
| gas is $95/MWh at current gas prices.
|
| Similarly, fusion does not promise cheaper energy, at least I
| have never seen a numerical argument that could support that.
| If you have one, I'd love to see it. Fusion is mostly
| interesting because it doesn't exist so people can project
| whatever characteristics they want on it.
| pfdietz wrote:
| Helion hasn't released details, but they imply they'd be much
| cheaper. At this point I can't disprove that, as their scheme
| does do away entirely with turbines and generators and could
| have much lower cooling requirements.
| kibwen wrote:
| Fusion is ready, and it's been ready for about 4-ish billion
| years. Once you deploy the panels needed to collect space-based
| fusion, there will likely never be an economical argument for
| Earth-based fusion. There's only so much simplication you can
| apply to a machine designed to contain a miniaturized star,
| especially compared to a dead-simple dirt-cheap solar panel.
| gridspy wrote:
| You say "likely never" but eventually we'll have covered the
| earth's surface in solar panels. Unless we are transitioning
| to space based solar and transmission we'll want fusion to
| increase energy generation beyond surface irradience of
| earth.
|
| In the meantime, solar panels for massive generation also
| incur transmission costs to centralize that energy for any
| major energy usages. We might want to keep having high power
| generators next to super-high energy consumers. For instance
| our (theoretical) hyperspace communication and computation
| array. Right now those usages are things like Arc Furnaces,
| Aluminum smelters, data-centers, ...
|
| Plus, we'll want to have figured out that fusion tech so we
| can build it into our spaceships travelling out beyond Mars
| as an energy source and hopefully also a thrust source. We
| want to master that tech on Earth's surface for sure.
| danans wrote:
| > Therefore, they believe, we should deemphasize solar in favor
| of "firm" sources of energy like gas turbines, next-generation
| nuclear or advanced geothermal.
|
| One cool thing about advanced geothermal is that it can load
| follow solar like natural gas does today: ramp down when solar is
| abundant and ramp up when it is not. That could come from slowing
| the turbines, or even by storing the extracted heat (in molten
| salt) during peak solar hours and using it to turn the turbines
| to meet peak demand or overnight.
|
| They are in many ways a great complement for each other.
| doctoboggan wrote:
| The company I work for (as a data engineer) does utility scale
| solar + battery installation and site management. We recently
| finished a large scale installation just outside of Las Vegas (by
| some measures the largest in the US). It was backed by a PE firm.
| Costs are getting so low, the tech so predictable, and with
| battery warranties around 20 years the PE firm is able to get
| pretty high return with a fairly low risk. They enter into a
| "power purchase agreement" with the utility so they know how much
| they will be able to sell the power for, and as long as we
| collect data on the batteries they will be able to be warrantied
| if there is an issue (but there rarely are issues).
|
| The batteries are by far the most expensive portion of the setup.
| The solar by comparison is dirt cheap. We have single axis
| tracking like mentioned in the article. Every day we fully charge
| the batteries, and discharge them in the evening.
| algo_trader wrote:
| > I work for (as a data engineer) does utility scale solar +
| battery installation and site management.
|
| Did you build your own excel/python nightmare or is everyone
| using 3rd party management software for this?
|
| > as long as we collect data on the batteries they will be able
| to be warrantied
|
| Can you share some of the data? Beyond power in/out, do you
| monitor humidity, vibrations, temperature ?
| doctoboggan wrote:
| Our data pipeline looks like this:
|
| hardware/PLC --modbus--> kepware --mqtt--> mosquito broker
| --mqtt--> mqtt2prometheustool --http--> Victoria Metrics
|
| The mqtt2prometheustool is something we developed in house. I
| am looking at removing one or more of the above steps and
| using telegraf instead, as it can ingest OPCUA or modbus data
| directly.
|
| We use excel files just as the output of our reporting tools.
| For analysis it's the standard python data science stack of
| pands/numpy/scipy. Most people work in Jupyter notebooks, and
| their tools are eventually moved to services in our k8s
| cluster.
|
| Temp and voltage are the main "cell level" datapoints we
| collect. I don't think we have any vibration sensors at site
| now.
| dalyons wrote:
| how do you like it? I have a 20 year career in large scale
| consumer app/web/b2c tech, but i've always wanted to work in
| renewables. Is it easy enough to break into? Is there many non-
| hardware roles (i have no hardware skills)? any advice / vibes?
| doctoboggan wrote:
| It's a great job. I joined with no prior experience in the
| field, and none of the positions on my team require hardware
| experience.
| Ringz wrote:
| The great (!) article misses the holy grail of the Energiewende
| in the chapter ,,Addressing the challenges of solar
| intermittency": a intercontinental smart grid. As shown by data
| of ENTSO-E in Europe a power system plays a crucial part to
| overcome intermittency problems of renewables.
| GratiaTerra wrote:
| Personal energy abundance and off grid independence is the good
| life and it means using all electric appliances and vehicles,
| heat pump and hot tub, powered by nonpolluting energy generation.
|
| As the article alluded to, scale is important for this to work
| (although I get by fine using only thirty 400 watt panels (12kw)
| and this covers less than 30% of my roof).
|
| As a remote worker, not commuting daily large distances is key to
| this system working. If I had to commute 60 miles every day I
| would need additional 10-15 panels to power the Ford Lightning EV
| truck, and if I was charging at night I would need six additional
| 100A 48v batteries.
| triceratops wrote:
| If you had to commute daily, wouldn't you buy a smaller
| commuter EV? Something from Hyunda or Nissan? The depreciation
| on that Lighting will be rough if you had to drive it 80
| miles/day.
| GratiaTerra wrote:
| Yes, utility vehicles are by definition not ideal for
| personal commuting.
| Calwestjobs wrote:
| In Czech republic - europe - they made law that says anyone can
| built up to 100 kWp solar array, without any building permits,
| township meetings, HOA nonsense etc. You want it, you can build
| it.
|
| Best way to be independent of your neighbors polluting your air
| with their wood burning furnace is show them PV works, and is
| cheap.
| GratiaTerra wrote:
| Yes, this wasn't economically feasible 10 years ago due to
| the rapid improvement in batteries, inverters, heat pumps for
| air conditioning and water heating, etc. I've been living off
| grid over 20 years but its only recently that its at least as
| good as a connected 200 amp grid power service with ample
| 220v for residential needs.
| sanj wrote:
| One thing I haven't seen much coverage on is how to tap into the
| giant batteries we're driving around in our electric vehicles.
| These are much bigger than what's currently being deployed in
| houses.
|
| The V2H standards are just now coming online:
| https://electrek.co/2025/02/21/nema-bidirectional-ev-chargin...
| raphaelj wrote:
| There might not even be any need for V2G or V2H.
|
| Just charging your car when the demand is low is probably
| enough to drastically reduce the overall cost of the system.
| And this has basically no impact on the battery lifespan.
| kieranmaine wrote:
| A trial in the UK resulted in customers earning up to
| PS725/year [1]. With increased renewables on the grid leading
| to increased flutucations in the wholesale price of
| electricity, providing V2G/V2H will further reduce a
| customer's electricity bill on top of the savings offered by
| smart charging eg. Charge Anytime Tariff is 7p per kWh for EV
| charging [2] vs 27p kWh average Apr - Jun 2025 [3].
|
| 1. https://www.kaluza.com/case-studies/case-study-kaluza-
| enable...
|
| 2. https://www.ovoenergy.com/electric-cars/charge-anytime
|
| 3. https://www.nimblefins.co.uk/average-cost-electricity-kwh-
| uk
| zekrioca wrote:
| High demand is not the sole reason for outages.
| r00fus wrote:
| V2L is one of the reasons I bought the car I did - instead of
| getting battery backup for the random outages that PG&E gifts
| us (literally power drops likely to happen whenever we gust
| over 25mph), I installed a 12 circuit transfer switch and my
| 75kWh battery in the car can provide reasonable backup without
| running cables throughout the house (reasonable = 1.9kW max so
| no hair dryers or running toaster oven + microwave at the same
| time).
|
| Newer vehicles (like 2025 Ioniq5) can do 12kW throughput (and
| many trucks can do 9+ kW already).
|
| Once V2H standards are confirmed and deployed I would be able
| to integrate the Car batteries with home batteries and solar.
| PaulDavisThe1st wrote:
| A Generlink would have simplied your transfer switch
| rewiring. Just connect the external 240V supply (be it your
| vehicle, batteries, or a fossil fuel powered generator), and
| the Generlink shuts down the grid connection and delivers to
| your regular main service panel. You might need to turn some
| circuits off when using it, but which circuits and when
| remains flexible and context dependent.
| malchow wrote:
| Arbitrary vehicle to home/home battery/grid connection is
| indeed coming in very short order.
|
| https://enphase.com/ev-chargers/bidirectional
|
| There are other products already available to do it (DCBel),
| and it can be hacked of course, but at the current moment
| everything comes with substantial corner case blind spots,
| mostly related to grid-forming/following switching and to the
| resilience of the power electronics.
| rixed wrote:
| There is also a risk factor to be considered before we decide to
| add massive energy storage within residential area. I've hear
| that one of the reason why the recent wildfires in LA had been so
| devastating was because the amount of available energy to fuel
| the fire (tanks, batteries) around modern homes is much larger
| than in the past.
| MostlyStable wrote:
| I'm extremely skeptical of that claim. I'd buy that, on the
| scale of individual houses, a large battery bank could make a
| fire worse. Once you get to the point of whole cities burning,
| I just don't buy that batteries make a difference. I _might_ be
| willing to believe that in some narrow technical sense some
| homes burned hotter or faster because they had batteries. I
| don't buy at all that, at the big scale, number of homes burned
| or total damage incurred was higher.
|
| That being said, yes, utility scale batteries do pose somewhat
| of a novel risk, especially as they are new and we are figuring
| out the engineering. A new installation in Moss Landing has
| burned twice in the past several months, although according to
| reports, the damage was entirely contained to the facility.
| adrianN wrote:
| A 40 kWh battery stores about as much energy as the bag of coal
| in your garage for the next barbecue.
| bryanlarsen wrote:
| If you could efficiently extract the energy, which you can't.
| A typical coal plant is 33% efficient. You can get 100%
| efficiency converting the coal to heat, but a heat pump can
| convert that battery energy to heat at 300-500% efficiency.
| ZeroGravitas wrote:
| There seems to be a real cultural obsession with going off grid,
| that this article reflects.
|
| It's therefore confusing if they're talking about a nation/state
| or a household.
|
| For a household, assuming you don't want to disconnect from the
| grid, the calculation is about how to offset as much of your
| energy costs you can displace with solar, and how to shift cheap
| energy from overnight with batteries as well as time shift solar
| generstion. A different and in many ways more interesting
| question in the abstract while also more practical too.
| SigmundA wrote:
| With net metering going away now people want batteries for self
| consumption, then the grid becomes a backup.
|
| In my area we still have net metering but the grid tends to go
| down a lot with even a mild storm, so many have backup propane
| generators, however some like me are doing whole house solar
| with batteries for backup instead, it cost 3x as much but pays
| you back over time with little maintenance compared to a
| generator.
|
| I will admit there is a prepper aspect, with well and septic
| and solar the only thing I need is food which I can try and
| grow. The Sol-Ark inverter in my install even offers EMP
| hardening which I almost went for :).
|
| Getting grid hookup in rural property can be expensive or
| impossible depending on where you are at, solar with satellite
| internet means no problem wherever you want to build if done
| right.
| buckle8017 wrote:
| There's really no such thing as the California grid from a
| reliability stand point.
|
| California is on the western interconnect, which is organized by
| wecc.
|
| The power on the western interconnect is more like 20%
| wind/solar.
|
| https://wecc-spdp-weccgeo.hub.arcgis.com/pages/power-generat...
| thelastgallon wrote:
| The duck curve can be easily flattened by using vertical panels
| which extend the production of solar a few hours in each
| direction. Vertical panels take no space (think every fence; or
| on farmland with enough space for big machinery to move), better
| performance (because heat isn't trapped), panels are always clean
| (daily gust of wind takes care of it). I'm sure there are many HN
| discussions on vertical panels.
| CrzyLngPwd wrote:
| I have been off-grid with a small solar generation system of
| 2.5kwh of solar and 3.6kwh of battery storage for a year.
|
| I had to run a generator a number of times during the darker
| weeks, but now we have longer days. I don't recall when I last
| ran it.
|
| With solar, or any off-grid system, the number one thing that
| needs to change is you.
|
| Switch stuff off, get energy efficient things, use power tools
| and charge their batteries when the sun is shining, use gas for
| hot water and cooking, and a log burner for heat (If I had my
| time again I would use a back boiler for water heating during the
| winter, and solar for water heating the rest of the time).
|
| When I lived in a typical house, I averaged around 12.5kwh per
| day. Now, it's around 2.5kwh per day.
| PaulDavisThe1st wrote:
| > a log burner for heat
|
| for areas that experience winter, this is a decisive issue.
|
| If you live in a passivhause-style home, air source heat pumps
| ("minisplits" for our US readers) may work, and you might be
| able (at least in the southwest of the USA, with high
| insolation during winter) to get away with local battery
| storage to cover your heating needs with PV.
|
| But if you don't, PV-driven heating during the winter, even
| with the very high COP's of air source heat pumps, is not
| realistic without much larger battery systems than you could
| reasonably have on site.
|
| Covering non-heating domestic electricity costs with PV these
| days is relatively easy, and we should do it as much as
| possible. Covering the heating part for places with winter
| climates (especially in areas with low insolation) is much,
| much harder and really requires effective grid infrastructure.
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