8/3/2026 at 4:15:45 PM
Also true for California for quite some time.https://www.canarymedia.com/articles/solar/california-solar-...
What's going to happen in the future is that May will be a month of extreme electricity abundance, with a good chunk of the electricity just not being collected at all because the grid doesn't need it, and it will be cheaper to have unused electricity in May than to have too little solar in December.
by epistasis
8/3/2026 at 7:12:46 PM
> What's going to happen in the future is that May will be a month of extreme electricity abundance, with a good chunk of the electricity just not being collected at all because the grid doesn't need itThis is already a thing in some places. Or, sometimes, because the grid can't _take_ it. Here's a dashboard for Irish energy production: https://www.smartgriddashboard.com/all/solar/?duration=month - on the wind and solar you'll notice that on big days, actual production is usually way below forecast production. This is sometimes due to actual mis-forecast, or due to renewable production being high enough that it meets total demand. But usually it's that the _grid_ can't take it; there is demand, but no way to get it there.
It's a chicken-egg problem, of course; you're not going to build excess grid capacity in the hopes that someone one day builds a wind farm, so in practice grid upgrades trail renewable sources.
by rsynnott
8/3/2026 at 4:19:00 PM
And eventually that arbitrage will be big enough to justify a pumped hydro/gravity/iron-air storage.by mekdoonggi
8/3/2026 at 4:26:43 PM
Doubtful, the tradeoff is solar cost versus storage cost. Pumped hydro and gravity are waaaaaaaay too expensive compared to excess solar panels. Pumped hydro takes massive construction projects, which are very very expensive these days. Gravity storage (non-water, meaning non-hydro) never made any sense at all, the material costs are just way too high.Iron-air storage is still being proven out, but it still requires so much material that only getting 1-2 cycles per year just won't justify it, because electricity is going to be so cheap.
It's hard to overstate how cheap solar panels are these days. Even in the US, which has costs 3x-5x the rest of the world because of failed protective tariffs.
by epistasis
8/3/2026 at 4:55:33 PM
>Doubtful, the tradeoff is solar cost versus storage cost.The arbitrage is solar cost vs storage cost vs other energy source cost vs capital cost vs transmission cost.
Appropriately priced risk with all of those factors in and what you get out is solar+storage capping the price of other energy sources.
by colechristensen
8/3/2026 at 4:29:31 PM
Lithium is the way, almost as cheap as sodium for a superior capability profile. Like solar, it just got cheap enough incredibly fast.https://pv-magazine-usa.com/2026/07/27/global-battery-storag...
https://www.spglobal.com/energy/en/news-research/latest-news...
https://ember-energy.org/latest-insights/global-electricity-...
by toomuchtodo
8/3/2026 at 4:54:26 PM
Cheaper yes, but I don't think Lithium is that cheap, or ever will be. I think storage (even the expensive ones like pumped hydro) will become more useful over time to handle day/night issues. Probably even enough to handle 2-4 week variations in weather. However for seasonal weather storage is going to be too expensive compared to just building a more solar panels that we don't use in summer.Of course once we have solar that we won't use in summer there will be programs to use that power. I suspect things like ore refining, steel mills, and the like: will start running in summer only. They will go offline in winter for maintenance. (Investors will make a ton of money buying in summer and selling in winter - as they already do for lots of other commodities that have seasonal aspects)
by bluGill
8/3/2026 at 10:19:17 PM
Cost is influenced by demand. To put this in perspective about 60 TWh of electricity is used globally per day. About 1 TWh of lithium batteries were produced last year.Even if every country tried to provision just one day of storage, that would cause a massive spike in demand that would inevitably drive up prices. Not to mention it would make EVs more expensive which would have its own negative consequences for emissions reductions.
by Manuel_D
8/3/2026 at 10:52:30 PM
Alternatively: the spike in demand will result in a similar spike in production capacity, leading to overall lower prices due to better economies of scale.Battery costs have declined by 99% in three decades. Solar isn't much different. Demand for both have exploded during that time period.
Besides, the current battery storage tech is just a side-product of the EV revolution. If grid battery storage becomes the main solution we'll undoubtedly see cheaper and easier-to-scale alternative tech like iron redox flow batteries be adopted. Bulky, lossy, impossible to transport? Don't care - it's cheap!
by crote
8/3/2026 at 10:25:59 PM
If necessary, we’ll switch to sodium chemistry for stationary storage if needed based on commodity input prices. With that said, incredible amounts of both lithium and sodium are cost effectively available today to achieve net zero.https://www.rethinkx.com/faq-and-mythbusting/myth-there-is-n...
by toomuchtodo
8/3/2026 at 4:57:22 PM
Pumped storage utility is tied to duty cycle. You want one cycle per day with some overage, not one cycle per year. A lot of the cost scales with storage volume.If you look at the pumped storage projects built and under construction in China, they are all daily focused.
by s1artibartfast
8/3/2026 at 5:08:03 PM
To play devil's advocate: there are also some limited opportunities to retrofit large reservoirs with some amount of back-pump, when there's a sufficient reservoir at the bottom site. Not a ton, but a bit. However even those opportunities, that already have massive dams, may not be economically feasible because solar panels are just so damn cheap.Solar's zero marginal cost generation, with cheap capital costs, requires rethinking a lot of the economics of electricity generation. Not paying for fuel changes so much, and it will take a while for people to internalize this.
by epistasis
8/3/2026 at 4:20:46 PM
Or possibly the return of some heavy industry?by kansface
8/3/2026 at 4:32:19 PM
I always wondered that - but will it be economical to have the plants not working in the months of the year that the energy isn't free?by ljf
8/3/2026 at 5:05:17 PM
Maybe. Depends on the plant. Nearly every plant goes through shutdowns for maintenance. If energy is a large cost they work with the utility (and vice versa - when the utility needs to shut down a big power plant they need industry to shutdown something at the same time). Many of them take December off for maintenance. My company has long pour iron in the foundry only at night: we get enough of a discount on power as to be worth paying the workers extra to work the night shift (I last checked this 15 years ago - I would not be surprised if this has changed now that the local power is mostly wind and thus has different factors)Of course every plant is different. There is a big difference between "batch" processes where you can shutdown after any batch, and "continuous" processes where startup/shutdown is a large process since the machines depend on running. They have different abilities to respond. Some plants/processes use more energy than others - obviously if they don't use much energy they don't care about free energy much either. The more energy a plant uses the more they are interested in cheap energy. In some cases a less efficient process may suddenly become better when solar is "free"
by bluGill
8/3/2026 at 5:01:24 PM
It's not "will it" it's just a series of balances, capital costs vs energy costs.If there's enough free energy and automation there gets to be a point where there will be people will start to disregard the capital costs as well and run 0ish input cost businesses with a vertical stack of stuff that they produced with 0ish input cost.
by colechristensen
8/3/2026 at 4:43:05 PM
I think the challenges for heavy industry aren't as much the cost of energy, as it is the capital cost, and a workforce that has lots of options for higher paying jobs.Heavy industries are usually pretty low on the value chain in economies. They do not provide much return on capital, compared to the high tech options and service options that are available in the US, but not available anywhere else in the world.
The rest of the (non-European) world dreams of the economic opportunities that are possible in the US, from Silicon Valley tech, to biotech, to the financial opportunities. China has been trying to climb up the value chain ladder for decades, and is slowly getting there.
It's mystifying to me why people are fantasizing about climbing down the value chain in the US, to being poorer, and allocating capital to things with lower return on investment. I just don't get it! What's the appeal?
by epistasis
8/3/2026 at 5:10:37 PM
Well, manufacturing capacity was the basis of US military dominance, which was the underpinning of the post WW2 US-led world order. That's pretty clearly eroded, and we're not sure we could win in a war against China, especially not a full-on war of attrition, and they're not sure about that either, and so they're steadily getting more willing to throw their weight around geopolitically, trying to get a setup that's more favorable to them. The difference in shipbuilding capacity is staggering, for example. Even if each of our ships had a 10-1 kill ratio, we'd still run out of ships first.My read on why we want it back, anyway. I'm sure there are other reasons, too.
by ericd
8/3/2026 at 10:32:25 PM
> we're not sure we could win in a war against ChinaThe USA couldn't even win a war against Afghanistan - which had basically no army and is the second-poorest country in the world. It couldn't win in Iraq, Niger, Yemen, Somalia, Lebanon, Cambodia, Cuba, Korea, Laos, Tibet, and of course Vietnam. It is currently very much not winning in Iran either.
The main power of the US was its ability to bomb anyone they want to, due to a worldwide network of military outposts and a huge fleet of aircraft carriers. Prior to the drone era, this meant it was able to bully most countries into doing whatever the US wants it to do. As is now becoming painfully clear, it is no longer viable to maintain air superiority with a few dozen super-expensive toys, and hosting a US base is rapidly becoming a serious liability.
The USA is absolutely not going to win any kind of direct war. About the best possible outcome these days is maintaining its sphere of influence without either politically or economically ruining itself.
by crote
8/3/2026 at 5:26:51 PM
Manufacturing dominance was for WW2, but post WW2 it's really high tech and Silicon Valley that gave us dominance.Silicon Valley was built on defense contracts for control systems, that's what funded all early semiconductor work, what built the technical empire that led to software's dominance in more recent decades.
And Ukraine is proving that heavy manufacturing competence is not the key discriminator. Now light manufacturing, high tech, and bottom-up organization and logistics are letting a small country defend itself against a far far far larger enemy with 4x the people and an absolutely massive dominance in heavy industry and manufacturing of heavy vehicles.
The biggest weakness of Ukraine is the same weakness of the US at the moment: inability to manufacture large amounts of interceptor missiles for air defense. That's not a heavy industry problem, that's a technology problem, a logistics problem, an operations problem. This requires the skill of Apple, not the skills of GM. And in the time it takes the US to scale up production, Ukraine is going to invent their own far cheaper option from scratch.
And that's because the US has not yet moved beyond the style of military industry built on massive high-capital manufacturing, that's slow moving and design iteration measured in years rather than months. The US is currently repeating the same mistake, but even worse, with its drone initiatives because the rewards are based purely on corrupt personal relationships rather than any sort of competitive process.
Heavy industry and manufacturing are not the model for building a military of the future, or an economy of the future.
by epistasis
8/3/2026 at 5:36:51 PM
If by heavy industry you mean shitloads of steel production, I mostly agree, but if you count things like domestic rare earth minerals processing, semiconductors, solar, batteries, I'm not so sure. I don't know the official ontology of what goes in heavy vs light. If magnets are going to be one of the key strategic resources in warfare, though, we should probably get that supply chain down. And being able to replace ship losses still seems relevant.And yeah, controls, signal processing, decisionmaking, etc are all going to be big determinants, and we're no slouches in that stuff. It used to take a huge bomber fleet and an absurd number of bombs to score as many hits on target as a single B-52 load can now score, thanks to the ability to strap cheap guidance packages onto dumb bombs, margin of error has gone from on the order of half a mile to single digit yards.
by ericd
8/3/2026 at 9:59:27 PM
>Manufacturing dominance was for WW2, but post WW2 it's really high tech and Silicon Valley that gave us dominance.There was a good 40+yr there, more in some industries.
Selling the industrial economy piecemeal to china under the guise of environmentalism, worker protection, etc, etc for pennies on the long term dollar was an intentional policy choice and a resounding failure. The winners from that of course don't want to see it framed that way.
by cucumber3732842
8/3/2026 at 6:19:33 PM
I think it's unlikely the next War will be won by tanks and Liberty ships.Beyond that there's still the economic viability problem in the US. A steel mill worker in the US makes 65k per year. In China they make 12K. This holds true for the rest of the heavy industry supply chain.
As the parent posts points out, what we are really fighting against here is baumol's cost disease.
Edit: a Chinese steel worker salary is about 80th percentile for Chinese workers - a very attractive gig.
US steel workers are about 40th percentile - worse than average.
by s1artibartfast
8/3/2026 at 7:22:03 PM
For sure, it's not going to be the same, but we need to be able to feed our missile launchers for more than a couple of weeks if we get into a peer conflict. That means building a lot of big physical things, quickly, and transporting a lot of those big physical things, quickly. For that last part, actually, maybe we do still need liberty ships...by ericd
8/3/2026 at 4:51:58 PM
> I just don't get it! What's the appeal?its the k shaped economy. the big opportunities are great if you can get into them, but otherwise all there is is serving coffee to the wealthy. People are already poorer without a ladder or fulfilling work at the bottom
by 8note
8/3/2026 at 4:57:57 PM
I could see that, if people actually wanted to work in those jobs in large numbers. Yet, poll after poll shows that people don't want to work in the jobs, they just want heavy industry and manufacturing to return to being a big part of the US economy.People understand that these jobs are worse than what's currently available, yet for some reason want them here.
by epistasis
8/3/2026 at 5:17:08 PM
I want those to be automated. I don't want anyone to have to work in a steel mill - it is hot dirty work that wears out your body. I wouldn't wish that on my worst enemy. However those plants are mostly automated and I know we will need them in some worst case scenarios.by bluGill
8/3/2026 at 9:41:27 PM
Why do people think steel mills would pay better or be more attractive than serving coffee. Hard jobs already exist and are in high demand.by s1artibartfast
8/3/2026 at 5:15:28 PM
There is a tremendous amount of money in those high capital costs enterprises. High tech can make you a lot of money, but you can also go bankrupt when everyone buys from your competitor - just like everything else. The world needs the things that heavy industry makes, and despite the large capital costs they are valuable. People are still making a lot of money in those industries - even if it is less than the silicon valley can make.Also industry is only low value so long as someone friendly to you has it. The world really worried about China climbing that latter because they are making some political moves that could lead to war. Maybe they won't, but China clearly is building a powerful military and they are not friendly to the freedoms that the US and western Europe likes. If it comes down to war we need heavy industry.
by bluGill
8/3/2026 at 4:35:47 PM
Large-scale battery storage is already expanding rapidly, and is way cheaper than pumped storage.by Rover222
8/3/2026 at 4:44:03 PM
pumped storage is still significantly cheaper for seasonal storage. The cut off is about 2 weeks now -- if you need to pull from storage more than twice a month batteries are cheaper. If you need to pull from storage less than twice a month pumped storage is cheaper.by bryanlarsen
8/3/2026 at 5:20:25 PM
The problem with pumped storage is most of the places we can use it are already taken and have been for years.> pumped storage is still significantly cheaper for seasonal storage
Only because most of the costs have been financially depreciated long ago. Try to build a brand new dam nearly anyplace and the costs will be much higher.
by bluGill
8/3/2026 at 5:31:16 PM
> we can use it are already takenThere are literally millions of unused locations identified that are suitable for pumped storage: https://re100.eng.anu.edu.au/global/
hydro generation sites are mostly taken. pumped storage doesn't need flow, just 2 reservoirs (one or both of which can be built) and a elevation change.
> a brand new dam
pumped storage facilities generally don't use dams.
by bryanlarsen
8/3/2026 at 6:03:01 PM
You have to have something to keep the water contained between the two.by bluGill
8/3/2026 at 6:17:02 PM
But those aren't dams. Dams are something that stops the flow of water. And it's this stoppage that causes the environmental problems.Reservoir walls might look like dams, but they're not dams.
by bryanlarsen
8/3/2026 at 10:54:58 PM
The main enviromental complaint is in flooding huge areas of land, which is the case with both dams and reservoir walls.by crote
8/3/2026 at 6:46:27 PM
Pedantically you are correct. However you are completely missing the point.by bluGill
8/3/2026 at 4:56:59 PM
In most practical cases, the cheapest way to provide carbon-neutral seasonal storage is to use the existing natural gas generators and feed them with carbon neutral synthetic gas. That synthetic gas is super expensive, but when you're only running it a couple times a year the gas is a tiny percentage of the cost.by bryanlarsen
8/3/2026 at 11:09:17 PM
This is such a painfully obvious solution that it is almost embarrassing that it even needs to be mentioned.The "but sometimes..." crowd is obsessed with the few hours a year when it is dark, windless, battery storage is empty, hydro isn't available, and all neighbors have the same situation. Who cares, just use gas peaker plants! We already have them!
Our goal is not and has never been to get a 100% solar grid. Our goal is to reduce CO2 emissions as soon as possible, and as fast as possible. If that means running gas generators for a few days every year, then that is totally fine.
Want to feed it with synthetic gas, or use carbon capture on the exhaust? Even better. Running cost is irrelevant, it is more than compensated by the basically-free electricity during the summer, do whatever is cheapest to build.
On top of that, you could perhaps even leave the turbines running without being fired the rest of the year. It would provide a nice source of inertia, after all - why build a standalone flywheel when you could just repurpose an emergency generator?
by crote
8/3/2026 at 6:46:09 PM
I meant it's cheaper when considering building an entirely new pumped storage facility, vs battery storage.by Rover222
8/3/2026 at 7:40:13 PM
A GWh of pumped storage is $25M, a GWh of batteries is $100M.More concretely, https://en.wikipedia.org/wiki/Fengning_Pumped_Storage_Power_... was built for about $50/KWh. Which is about the same price as batteries.
But that's a daily storage facility. If you undersized it's pumps so it took weeks to refill rather than ~10 hours to make it a seasonal facility, it would have been significantly cheaper.
by bryanlarsen
8/3/2026 at 5:01:59 PM
can you explain the economics of that to me, because it doesn't track my understanding.Are you just talking about total capacity dominated breakeven? The economics of both want daily cycles. Water has a more favorable power/$ scaling curve for storage if you have a site.
by s1artibartfast
8/3/2026 at 5:25:49 PM
Any sort of seasonal storage is horrendously expensive and completely infeasible using economics alone. It's really only a concern once our power grid is 98%-99% carbon-neutral and we want to get it to 100%.A battery storage facility has watts and watt-hours roughly equivalent. A typical storage battery is around "1C" -- it takes about one hour to fully charge or discharge. The limiting factor on the build price is the MWh -- if you keep the power the same but double the storage the price of the plant still roughly doubles.
A typical daily storage facility wants around 4C, so that coupling between power and energy for batteries is not a significant drawback.
Seasonal storage is not coupled in this way. You increase MWh by increasing the size of your reservoirs. You increase MW by increasing the number of pumps/turbines. MWh is usually a lot cheaper than MW. A typical pumped storage facility today has MWh only being 10-20X the MW which means they're tuned for daily-ish usage (see top line). One tuned for seasonal usage would have that ratio >> 100.
by bryanlarsen
8/3/2026 at 5:55:07 PM
humm, I was thinking about it differently. I would expect most pumped storage to have variable and diminishing cost per MWh (up to a point). Part of this is the turbines, but also other fixed project costs and economies of scale. If you hold MW fixed, the First MWh of the project is going to be more than the next until you hit diminishing returns due to specific site saturation.As an interesting side note, China has roughly 80 GW of pumped storage built or under construction. Most of the big ones I have looked at are about "10C".
This is comparable to the GW output from their nuclear reactors built or under construction.
Tangent: have you been following the Medog Hydropower Station? https://en.wikipedia.org/wiki/Medog_Hydropower_Station
by s1artibartfast
8/3/2026 at 4:32:46 PM
Except the water is in short supply, so where's that magically coming from? The Great Salt Lake is shrinking and specific to Utah. Just look at Lake Meade and Hoover Dam as an example.by dylan604
8/3/2026 at 4:41:02 PM
The water requirements for pumped hydro for seasonal storage is a lot less than for generation.- pumped hydro reuses the water in a loop rather than sending it downstream like generation
- pumped hydro only needs to produce power a few times a year rather than 24/7/365 like generation.
by bryanlarsen
8/3/2026 at 5:22:31 PM
Only if there is a very large lake at the bottom. If that lake doesn't exist then you have to build it at great cost. You also lose a lot to evaporation if you do this.by bluGill
8/3/2026 at 8:32:43 PM
The 3.6 GW Fenging pumped storage facility holds 53 thousand acre-feet of water. Lake Mead holds 28 million acre-feet of water to run a 2 GW generator.by bryanlarsen
8/3/2026 at 9:44:38 PM
Just because you're using less water to power a more efficient generator does not mean the water in the lake is any less susceptible to evaporation and less water from upstream to replenish the lake.by dylan604
8/3/2026 at 5:28:01 PM
Where "very large" is still a lot smaller than the water requirements for hydro generation.by bryanlarsen
8/3/2026 at 6:02:12 PM
Large enough to replace all that water requirements, without making the lake levels so high that it impacts generation. Which is to say your lake at the bottom needs to have a large surface area when full - much larger than the lake at the top.by bluGill
8/3/2026 at 5:14:05 PM
moreover, If you built a pumped storage facility on lake Meade, it would have greater height and power from release the lower the lake wasby s1artibartfast
8/3/2026 at 8:55:36 PM
If only we could use that extra power to make methane for later power plant useageby jvanderbot
8/3/2026 at 10:15:35 PM
The idea has been around for decades: https://en.wikipedia.org/wiki/Power-to-gasThe obstacle for this process (and in synthetic hydrocarbon fuels more generally) is obtaining the carbon dioxide efficiently. Atmospheric carbon dioxide is in too low of a concentration to be viable. You could source the carbon from coal, but that makes it no longer carbon neutral.
Prometheus fuels is one of several startups pursuing this kind of technology. But it's still blocked on effective air capture of carbon dioxide.
by Manuel_D
8/3/2026 at 9:45:38 PM
While the energy used couldn't be recovered, desalinating water for later would be a good use for California, given how the climate is going to go. Not that desalination plants exist for free.by fragmede
8/3/2026 at 4:54:13 PM
Solar harvest time.by gtowey
8/3/2026 at 6:12:07 PM
Make ray while the sun's shinin'by jareklupinski
8/3/2026 at 8:24:33 PM
Not the future, now.Most Australians now get free power for three hours a day because there is simply so much.
This is the way.
by testing22321