16 ms·

Understanding Solar Energy

261 points by chmaynard 2y ago

pfdietz 2y ago
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/scientificamerican0114-521.pdf 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-of-solar-energy 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 2y ago
  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 2y ago
    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 https://doi.org/10.3929/ethz-b-000445597
    - bryanlarsen 2y ago
      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 2y ago
        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 2y ago
    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 2y ago
  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-underestimated/ https://www.carbonbrief.org/guest-post-why-solar-keeps-being... https://www.pv-magazine.com/2021/03/31/solar-still-largely-underestimated/ https://www.pv-magazine.com/2021/03/31/solar-still-largely-u... https://www.theenergymix.com/leading-climate-models-underestimate-clean-energy-progress-overstate-cost-study-finds/ https://www.theenergymix.com/leading-climate-models-underest... https://climatenexus.org/climate-change-news/iea-historically-underestimates-renewables-overestimates-fossils/ https://climatenexus.org/climate-change-news/iea-historicall...
  - epistasis 2y ago
    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 2y ago
      It was also underestimation of China. Outright chauvinism there.
    - Ringz 2y ago
      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.
- jillesvangurp 2y ago
  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 2y ago
  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 2y ago
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 2y ago
  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 2y ago
  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-get-cheap-part https://www.construction-physics.com/p/how-did-solar-power-g...
- doctoboggan 2y ago
  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.
bryanlarsen 2y ago
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/BVTDJPZTUnfCKRkDQJDEvQcUwtACMroC/assets/images/optimized/rev-7227a3a/reneweconomy.com.au/wp-content/uploads/2024/05/california-gas-903x500.jpg https://cdn-ilcjnih.nitrocdn.com/BVTDJPZTUnfCKRkDQJDEvQcUwtA... https://reneweconomy.com.au/battery-storage-is-dramatically-reshaping-the-california-grid-and-finally-moving-it-away-from-gas/ https://reneweconomy.com.au/battery-storage-is-dramatically-...
- epistasis 2y ago
  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 2y ago
    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 2y ago
      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.
losvedir 2y ago
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 2y ago
  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 2y ago
    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.)
1970-01-01 2y ago
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 2y ago
  There are studies (at the bottom of my post: https://news.ycombinator.com/item?id=43424310 https://news.ycombinator.com/item?id=43424310) showing that storage is mostly a political issue.
- epistasis 2y ago
  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 2y ago
    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 2y ago
  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.
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danans 2y ago
> 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 2y ago
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 2y ago
  > 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 2y ago
    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.
    - 2y ago
Ringz 2y ago
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.
- zizee 2y ago
  How do the costs of long distance, high voltage lines compare to batteries for addressing solar intermittency?
  - pyrale 2y ago
    It really depends on what you call "long distance". Anyway, transportation loss for entsoe is public data [1]. You'd need to cross it with production/consumption data [2] in order to get relative numbers. For instance, France consumed 442 TWh and reported 1.07TWh of losses in 2022, which would be about 2.5% transportation losses. [1]: https://eepublicdownloads.blob.core.windows.net/public-cdn-container/clean-documents/mc-documents/ITC_Transit_Losses_Data/entso-e_ITC_Transit_Losses_Data_report_2022.pdf https://eepublicdownloads.blob.core.windows.net/public-cdn-c... [2]: https://eepublicdownloads.blob.core.windows.net/public-cdn-container/clean-documents/Publications/Statistics/Factsheet/entsoe_sfs2022_web.pdf https://eepublicdownloads.blob.core.windows.net/public-cdn-c...
  - hnaccount_rng 2y ago
    Keep also in mind that batteries do two things: They can move loads in time, but they can also reduce transmission capacity requirements by increasing utilisation. As long as there is some time where the transmission line is not fully loaded (which today is true for _any_ transmission line even the limiting ones), then a battery on both ends allows you to use the capacity longer by charging the battery before the bottleneck with excess and once the input falls below discharging the battery to keep the line utilisation high. The downside of this is that you now have a system that comes with all kinds of nasty additional complexities and failure cases from control theory.
GratiaTerra 2y ago
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 2y ago
  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 2y ago
    Yes, utility vehicles are by definition not ideal for personal commuting.
- Calwestjobs 2y ago
  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 2y ago
    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.
- deleted 2y ago
nonelog 2y ago
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sanj 2y ago
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-charging-standard/ https://electrek.co/2025/02/21/nema-bidirectional-ev-chargin...
- raphaelj 2y ago
  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 2y ago
    A trial in the UK resulted in customers earning up to £725/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-enabled-vehicle-to-grid-v2g-charging/ https://www.kaluza.com/case-studies/case-study-kaluza-enable... 2. https://www.ovoenergy.com/electric-cars/charge-anytime https://www.ovoenergy.com/electric-cars/charge-anytime 3. https://www.nimblefins.co.uk/average-cost-electricity-kwh-uk https://www.nimblefins.co.uk/average-cost-electricity-kwh-uk
  - zekrioca 2y ago
    High demand is not the sole reason for outages.
- r00fus 2y ago
  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.
rixed 2y ago
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 2y ago
  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 2y ago
  A 40 kWh battery stores about as much energy as the bag of coal in your garage for the next barbecue.
  - bryanlarsen 2y ago
    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.
    - adrianN 2y ago
      For the purpose of "burn your house down", the energy is usually extracted fairly efficiently from both coal and a battery.
ZeroGravitas 2y ago
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 2y ago
  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.
- zejn 2y ago
  Evolving this line of thought further, if you do not want to disconnect from the grid, there's also an option to participate in the electricity market. Someone with a battery can buy up cheap electricity at night or whenever their electricity supplier deems it off-peak and thus cheap, so a battery can heavily influence the average price of energy as calculated here by Michael de Podesta: https://protonsforbreakfast.wordpress.com/2025/02/16/the-most-expensive-month-of-the-year/ https://protonsforbreakfast.wordpress.com/2025/02/16/the-mos... The other way to participate in the electricity market is that in EU the end users can access a plan that in some way reflects day-ahead market prices. If you have a battery, you can now buy the midday solar dip around 0 eur/mwh energy plus network charges and sell at the evening price of 300 eur/mwh.
buckle8017 2y ago
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-generation https://wecc-spdp-weccgeo.hub.arcgis.com/pages/power-generat...
thelastgallon 2y ago
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 2y ago
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.
- deleted 2y ago
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- PaulDavisThe1st 2y ago
  > 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.
  - nick3443 2y ago
    Ground source heat pump might help close the gap
- deleted 2y ago
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Veedrac 2y ago
The author misses a perhaps unintuitive point: the cost of storage depends also on the cost of energy. By the time you've overbuilt 2x, a full extra 100% of your demand is sitting around literally free at odd hours. Traditionally, moving energy around means batteries, and yes maybe your battery costs more than just generating new electricity from a less efficient new solar panel at odd hours. But batteries are optimized for energy being expensive, where losses are wasteful. Consider this really simple, dirt cheap alternative: plug your free energy into a pool of water and collect the hydrogen from it. Burn the hydrogen later, and point the light at your idle solar panels. It's hellishly inefficient, but I repeat: the energy is free. You are only minimizing capital costs, at least until other people catch up and start shifting load some other way. The sane point on this curve probably looks something along the lines of a mix of batteries and synthetic fuels powering existing fossil fuel plants. The nice thing about going all the way to synthetic fuels and not hydrogen is that long term storage becomes trivially cheap, so it starts offsetting your winter load as well.
- Matumio 2y ago
  It's a very long stretch from "generate hydrogen" to "powering existing fossil fuel plants". The most unlikely part is not even creating renewable fuels (that is a stretch already), but the idea that those fuels are going to be compatible with existing plants and infrastructure. It's not impossible, but it would probably be the least economical way to go about it. I recommend reading some industrydecarbonization.com articles for going a bit more in-depth about the why.
  - akamaka 2y ago
    Hydrogen-ready power plants are already being built, so that’s actually the least difficult part of the problem. The current bottleneck is actually producing the hydrogen, and next will be building the transport infrastructure. https://www.latitudemedia.com/news/hydrogen-ready-power-plants-arent-actually-ready-for-hydrogen/ https://www.latitudemedia.com/news/hydrogen-ready-power-plan...
- pyrale 2y ago
  > It's hellishly inefficient, but I repeat: the energy is free. Can you give pointers about who gives away hydrogen generation systems for free? Because the cost of energy usually factors in the cost of amortizing equipment required to produce and distribute it. > The nice thing about going all the way to synthetic fuels and not hydrogen is that long term storage becomes trivially cheap Once you've financed all of the horribly expensive capital expenditure, and provided you disregard that operating costs actually require paying people to monitor, repair and operate that infrastructure, the rest is basically free.
dzonga 2y ago
solar is nice for residential. you will still need gas for cooking + water heating. ohh yeah plus transportation i.e hybrid for long distance travellers or pure electric for city travellers. anything else i.e industrial both heavy & light manufacturing nothing beats hydrocarbons
tigroferoce 2y ago
Great article. I'd be interested with something similar for industrial and public transit cases. I totally get that it's feasible to run a common household with 100% solar+batteries, but I'm less convinced a train or an hospital can be run during a winter evening with solar+batteries alone. Let alone one of those new fancy AI datacenter.
kragen 2y ago
This article is good overall, and the map of solar capacity factor by US state is especially good, but it does have some flaws. First, and most trivially, Potter's plot of PV module prices overstates their cost by a factor of about three to five. His last data point is US$0.31 per (peak) watt in 02023. https://www.solarserver.de/photovoltaik-preis-pv-modul-preisindex/ https://www.solarserver.de/photovoltaik-preis-pv-modul-preis... shows a price of 0.26€ per peak watt in June 02023 for "mainstream" solar panels, which is in reasonably good agreement. But "low cost" panels were only €0.16/Wp, and since then prices have dropped by more than half, to €0.110/Wp for mainstream panels and €0.070/Wp for low-cost. (A footnote misstates this cost as $36 per megawatt, which would be $0.000036/W.) Prices in the US are of course much higher, but that's due to inefficient regulatory interference in the market to protect uncompetitive and environmentally destructive fossil-fuel interests. Another weak point is that the article doesn't consider thermal energy storage systems, neither sensible heat energy storage systems like a hot water heater or a sand battery, nor phase-change energy storage like the ice chillers used for decades in many office buildings and the MIT Solar I house built in 01939†, nor TCES systems using desiccants such as muriate of lime, carnallite, or tachyhydrite. Sensible heat energy storage has been a crucial part of domestic climate control for millennia, for example in the form of adobe, and can time-shift your entire HVAC energy load to hours when your solar panels are producing. The newer systems may be able to do the same at a lower cost and are certainly easier to retrofit into existing construction. This will dramatically drop the storage requirements for things like his example house, though it will not help with transportation and much industrial energy consumption. Maybe its most glaring weak point, though, is that it compares costs in the US and Europe, but entirely ignores China, where the vast majority of new power plants are being built, where the majority of world coal consumption happens, and where the overwhelming majority of photovoltaic panels are made. (India and the Middle East are also ignored and may turn out to be very important, but at present their potential is largely unrealized.) Writing an article about understanding solar energy this year without talking about China is like writing an article about understanding automobiles in 01940 without talking about the US. You can probably find a magazine article from 01940 that does that, but probably only in French. ______ † You could argue that the qanat represents a form of ancient Zarathustran phase-change energy storage that is much older than MIT Solar I, but I think that only applies if your buildings are responsible for condensing the water to fill the qanat.
asdf333 2y ago
other way to deal with intermittency is to dynamically price electricity. then people can shut off/on usage in response. many activities do not need to be done exactly at a certain time. it doesn’t all need to be fixed on the supply side

261 points by chmaynard 2y ago

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/scientificamerican0114-521.pdf 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-of-solar-energy 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 2y ago
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 2y ago
  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 https://doi.org/10.3929/ethz-b-000445597
  - bryanlarsen 2y ago
    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 2y ago
      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 2y ago
  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 2y ago
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-underestimated/ https://www.carbonbrief.org/guest-post-why-solar-keeps-being... https://www.pv-magazine.com/2021/03/31/solar-still-largely-underestimated/ https://www.pv-magazine.com/2021/03/31/solar-still-largely-u... https://www.theenergymix.com/leading-climate-models-underestimate-clean-energy-progress-overstate-cost-study-finds/ https://www.theenergymix.com/leading-climate-models-underest... https://climatenexus.org/climate-change-news/iea-historically-underestimates-renewables-overestimates-fossils/ https://climatenexus.org/climate-change-news/iea-historicall...
- epistasis 2y ago
  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 2y ago
    It was also underestimation of China. Outright chauvinism there.
  - Ringz 2y ago
    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.
jillesvangurp 2y ago
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 2y ago
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 2y ago

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 2y ago
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 2y ago
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-get-cheap-part https://www.construction-physics.com/p/how-did-solar-power-g...
doctoboggan 2y ago
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.

bryanlarsen 2y ago

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/BVTDJPZTUnfCKRkDQJDEvQcUwtACMroC/assets/images/optimized/rev-7227a3a/reneweconomy.com.au/wp-content/uploads/2024/05/california-gas-903x500.jpg https://cdn-ilcjnih.nitrocdn.com/BVTDJPZTUnfCKRkDQJDEvQcUwtA... https://reneweconomy.com.au/battery-storage-is-dramatically-reshaping-the-california-grid-and-finally-moving-it-away-from-gas/ https://reneweconomy.com.au/battery-storage-is-dramatically-...

epistasis 2y ago
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 2y ago
  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 2y ago
    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.

losvedir 2y ago

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 2y ago
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 2y ago
  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.)

1970-01-01 2y ago

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 2y ago
There are studies (at the bottom of my post: https://news.ycombinator.com/item?id=43424310 https://news.ycombinator.com/item?id=43424310) showing that storage is mostly a political issue.
epistasis 2y ago
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 2y ago
  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 2y ago
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.

deleted 2y ago

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danans 2y ago

> 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 2y ago

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 2y ago
> 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 2y ago
  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.
  - 2y ago

Ringz 2y ago

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.

zizee 2y ago
How do the costs of long distance, high voltage lines compare to batteries for addressing solar intermittency?
- pyrale 2y ago
  It really depends on what you call "long distance". Anyway, transportation loss for entsoe is public data [1]. You'd need to cross it with production/consumption data [2] in order to get relative numbers. For instance, France consumed 442 TWh and reported 1.07TWh of losses in 2022, which would be about 2.5% transportation losses. [1]: https://eepublicdownloads.blob.core.windows.net/public-cdn-container/clean-documents/mc-documents/ITC_Transit_Losses_Data/entso-e_ITC_Transit_Losses_Data_report_2022.pdf https://eepublicdownloads.blob.core.windows.net/public-cdn-c... [2]: https://eepublicdownloads.blob.core.windows.net/public-cdn-container/clean-documents/Publications/Statistics/Factsheet/entsoe_sfs2022_web.pdf https://eepublicdownloads.blob.core.windows.net/public-cdn-c...
- hnaccount_rng 2y ago
  Keep also in mind that batteries do two things: They can move loads in time, but they can also reduce transmission capacity requirements by increasing utilisation. As long as there is some time where the transmission line is not fully loaded (which today is true for _any_ transmission line even the limiting ones), then a battery on both ends allows you to use the capacity longer by charging the battery before the bottleneck with excess and once the input falls below discharging the battery to keep the line utilisation high. The downside of this is that you now have a system that comes with all kinds of nasty additional complexities and failure cases from control theory.

GratiaTerra 2y ago

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 2y ago
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 2y ago
  Yes, utility vehicles are by definition not ideal for personal commuting.
Calwestjobs 2y ago
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 2y ago
  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.
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nonelog 2y ago

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sanj 2y ago

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-charging-standard/ https://electrek.co/2025/02/21/nema-bidirectional-ev-chargin...

raphaelj 2y ago
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 2y ago
  A trial in the UK resulted in customers earning up to £725/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-enabled-vehicle-to-grid-v2g-charging/ https://www.kaluza.com/case-studies/case-study-kaluza-enable... 2. https://www.ovoenergy.com/electric-cars/charge-anytime https://www.ovoenergy.com/electric-cars/charge-anytime 3. https://www.nimblefins.co.uk/average-cost-electricity-kwh-uk https://www.nimblefins.co.uk/average-cost-electricity-kwh-uk
- zekrioca 2y ago
  High demand is not the sole reason for outages.
r00fus 2y ago
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.

rixed 2y ago

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 2y ago
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 2y ago
A 40 kWh battery stores about as much energy as the bag of coal in your garage for the next barbecue.
- bryanlarsen 2y ago
  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.
  - adrianN 2y ago
    For the purpose of "burn your house down", the energy is usually extracted fairly efficiently from both coal and a battery.

ZeroGravitas 2y ago

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 2y ago
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.
zejn 2y ago
Evolving this line of thought further, if you do not want to disconnect from the grid, there's also an option to participate in the electricity market. Someone with a battery can buy up cheap electricity at night or whenever their electricity supplier deems it off-peak and thus cheap, so a battery can heavily influence the average price of energy as calculated here by Michael de Podesta: https://protonsforbreakfast.wordpress.com/2025/02/16/the-most-expensive-month-of-the-year/ https://protonsforbreakfast.wordpress.com/2025/02/16/the-mos... The other way to participate in the electricity market is that in EU the end users can access a plan that in some way reflects day-ahead market prices. If you have a battery, you can now buy the midday solar dip around 0 eur/mwh energy plus network charges and sell at the evening price of 300 eur/mwh.

buckle8017 2y ago

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-generation https://wecc-spdp-weccgeo.hub.arcgis.com/pages/power-generat...

thelastgallon 2y ago

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 2y ago

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.

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PaulDavisThe1st 2y ago
> 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.
- nick3443 2y ago
  Ground source heat pump might help close the gap
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Veedrac 2y ago

The author misses a perhaps unintuitive point: the cost of storage depends also on the cost of energy. By the time you've overbuilt 2x, a full extra 100% of your demand is sitting around literally free at odd hours. Traditionally, moving energy around means batteries, and yes maybe your battery costs more than just generating new electricity from a less efficient new solar panel at odd hours. But batteries are optimized for energy being expensive, where losses are wasteful. Consider this really simple, dirt cheap alternative: plug your free energy into a pool of water and collect the hydrogen from it. Burn the hydrogen later, and point the light at your idle solar panels. It's hellishly inefficient, but I repeat: the energy is free. You are only minimizing capital costs, at least until other people catch up and start shifting load some other way. The sane point on this curve probably looks something along the lines of a mix of batteries and synthetic fuels powering existing fossil fuel plants. The nice thing about going all the way to synthetic fuels and not hydrogen is that long term storage becomes trivially cheap, so it starts offsetting your winter load as well.

Matumio 2y ago
It's a very long stretch from "generate hydrogen" to "powering existing fossil fuel plants". The most unlikely part is not even creating renewable fuels (that is a stretch already), but the idea that those fuels are going to be compatible with existing plants and infrastructure. It's not impossible, but it would probably be the least economical way to go about it. I recommend reading some industrydecarbonization.com articles for going a bit more in-depth about the why.
- akamaka 2y ago
  Hydrogen-ready power plants are already being built, so that’s actually the least difficult part of the problem. The current bottleneck is actually producing the hydrogen, and next will be building the transport infrastructure. https://www.latitudemedia.com/news/hydrogen-ready-power-plants-arent-actually-ready-for-hydrogen/ https://www.latitudemedia.com/news/hydrogen-ready-power-plan...
pyrale 2y ago
> It's hellishly inefficient, but I repeat: the energy is free. Can you give pointers about who gives away hydrogen generation systems for free? Because the cost of energy usually factors in the cost of amortizing equipment required to produce and distribute it. > The nice thing about going all the way to synthetic fuels and not hydrogen is that long term storage becomes trivially cheap Once you've financed all of the horribly expensive capital expenditure, and provided you disregard that operating costs actually require paying people to monitor, repair and operate that infrastructure, the rest is basically free.

dzonga 2y ago

solar is nice for residential. you will still need gas for cooking + water heating. ohh yeah plus transportation i.e hybrid for long distance travellers or pure electric for city travellers. anything else i.e industrial both heavy & light manufacturing nothing beats hydrocarbons

tigroferoce 2y ago

Great article. I'd be interested with something similar for industrial and public transit cases. I totally get that it's feasible to run a common household with 100% solar+batteries, but I'm less convinced a train or an hospital can be run during a winter evening with solar+batteries alone. Let alone one of those new fancy AI datacenter.

kragen 2y ago

This article is good overall, and the map of solar capacity factor by US state is especially good, but it does have some flaws. First, and most trivially, Potter's plot of PV module prices overstates their cost by a factor of about three to five. His last data point is US$0.31 per (peak) watt in 02023. https://www.solarserver.de/photovoltaik-preis-pv-modul-preisindex/ https://www.solarserver.de/photovoltaik-preis-pv-modul-preis... shows a price of 0.26€ per peak watt in June 02023 for "mainstream" solar panels, which is in reasonably good agreement. But "low cost" panels were only €0.16/Wp, and since then prices have dropped by more than half, to €0.110/Wp for mainstream panels and €0.070/Wp for low-cost. (A footnote misstates this cost as $36 per megawatt, which would be $0.000036/W.) Prices in the US are of course much higher, but that's due to inefficient regulatory interference in the market to protect uncompetitive and environmentally destructive fossil-fuel interests. Another weak point is that the article doesn't consider thermal energy storage systems, neither sensible heat energy storage systems like a hot water heater or a sand battery, nor phase-change energy storage like the ice chillers used for decades in many office buildings and the MIT Solar I house built in 01939†, nor TCES systems using desiccants such as muriate of lime, carnallite, or tachyhydrite. Sensible heat energy storage has been a crucial part of domestic climate control for millennia, for example in the form of adobe, and can time-shift your entire HVAC energy load to hours when your solar panels are producing. The newer systems may be able to do the same at a lower cost and are certainly easier to retrofit into existing construction. This will dramatically drop the storage requirements for things like his example house, though it will not help with transportation and much industrial energy consumption. Maybe its most glaring weak point, though, is that it compares costs in the US and Europe, but entirely ignores China, where the vast majority of new power plants are being built, where the majority of world coal consumption happens, and where the overwhelming majority of photovoltaic panels are made. (India and the Middle East are also ignored and may turn out to be very important, but at present their potential is largely unrealized.) Writing an article about understanding solar energy this year without talking about China is like writing an article about understanding automobiles in 01940 without talking about the US. You can probably find a magazine article from 01940 that does that, but probably only in French. ______ † You could argue that the qanat represents a form of ancient Zarathustran phase-change energy storage that is much older than MIT Solar I, but I think that only applies if your buildings are responsible for condensing the water to fill the qanat.

asdf333 2y ago

other way to deal with intermittency is to dynamically price electricity. then people can shut off/on usage in response. many activities do not need to be done exactly at a certain time. it doesn’t all need to be fixed on the supply side