4 ms·

And eventually that arbitrage will be big enough to justify a pumped hydro/gravity/iron-air storage.

by mekdoonggi 2mo ago

kansface 2mo ago
Or possibly the return of some heavy industry?
- ljf 2mo ago
  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?
  - colechristensen 2mo ago
    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.
  - bluGill 2mo ago
    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"
- epistasis 2mo ago
  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?
  - 8note 2mo ago
    > 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
    - epistasis 2mo ago
      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.
      - bluGill 2mo ago
        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.
    - 2mo ago
epistasis 2mo ago
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.
- toomuchtodo 2mo ago
  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-storage-capacity-projected-to-surge-sixfold-by-2030/ https://pv-magazine-usa.com/2026/07/27/global-battery-storag... https://www.spglobal.com/energy/en/news-research/latest-news/metals/010826-battery-storage-to-drive-lithium-demand-growth-globally https://www.spglobal.com/energy/en/news-research/latest-news... https://ember-energy.org/latest-insights/global-electricity-review-2026/global-electricity-insights/#batteries-are-making-daytime-solar-into-anytime-so https://ember-energy.org/latest-insights/global-electricity-...
  - bluGill 2mo ago
    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)
dylan604 2mo ago
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.
- bryanlarsen 2mo ago
  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.
  - bluGill 2mo ago
    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.
    - bryanlarsen 2mo ago
      Where "very large" is still a lot smaller than the water requirements for hydro generation.
      - bluGill 2mo ago
        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.
    - bryanlarsen 2mo ago
      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.
      - 2mo ago
Rover222 2mo ago
Large-scale battery storage is already expanding rapidly, and is way cheaper than pumped storage.
- bryanlarsen 2mo ago
  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.
  - bryanlarsen 2mo ago
    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.
    - crote 2mo ago
      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?
  - s1artibartfast 2mo ago
s1artibartfast 2mo ago
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.
- epistasis 2mo ago
  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.

And eventually that arbitrage will be big enough to justify a pumped hydro/gravity/iron-air storage.

kansface 2mo ago

Or possibly the return of some heavy industry?

ljf 2mo ago
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?
- colechristensen 2mo ago
  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.
- bluGill 2mo ago
  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"
epistasis 2mo ago
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?
- 8note 2mo ago
  > 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
  - epistasis 2mo ago
    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.
    - bluGill 2mo ago
      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.
  - 2mo ago

epistasis 2mo ago

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.

toomuchtodo 2mo ago
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-storage-capacity-projected-to-surge-sixfold-by-2030/ https://pv-magazine-usa.com/2026/07/27/global-battery-storag... https://www.spglobal.com/energy/en/news-research/latest-news/metals/010826-battery-storage-to-drive-lithium-demand-growth-globally https://www.spglobal.com/energy/en/news-research/latest-news... https://ember-energy.org/latest-insights/global-electricity-review-2026/global-electricity-insights/#batteries-are-making-daytime-solar-into-anytime-so https://ember-energy.org/latest-insights/global-electricity-...
- bluGill 2mo ago
  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)

dylan604 2mo ago

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.

bryanlarsen 2mo ago
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.
- bluGill 2mo ago
  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.
  - bryanlarsen 2mo ago
    Where "very large" is still a lot smaller than the water requirements for hydro generation.
    - bluGill 2mo ago
      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.
  - bryanlarsen 2mo ago
    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.
    - 2mo ago

Rover222 2mo ago

Large-scale battery storage is already expanding rapidly, and is way cheaper than pumped storage.

bryanlarsen 2mo ago
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.
- bryanlarsen 2mo ago
  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.
  - crote 2mo ago
    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?
- s1artibartfast 2mo ago

s1artibartfast 2mo ago

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.

epistasis 2mo ago
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.