25 ms·

Yeah, or water towers. No need to play god here.

supertrope 7mo ago
Pumped hydro energy storage relies on the cheapness of water and existing geology. If you have to build the chambers instead of damming a river it's too expensive. Most of the good spots to have a reservoir are already used. If you have to manufacture the bulk media instead of just using water it's too expensive.
- ben_w 7mo ago
  Pumped hydro doesn't need a river, "just"* rock which isn't water porous and some nearby body of water (lake, sea, whatever). The economics works out even if you were lifting concrete blocks rather than water, hence why you get pictures like this: https://en.wikipedia.org/wiki/File:Energy_Vault_Test_Tower_2021.jpg https://en.wikipedia.org/wiki/File:Energy_Vault_Test_Tower_2... The argument against lifting concrete is that you can dig a hole in the ground an pump water in/out of it for more reliability and lower cost than having a crane lift and lower concrete, and it's easy to make it much bigger both horizontally and vertically, so why bother. But it does appear to be economical even with that, and water is cheaper. We make lots of holes in the ground on a regular basis, including for extracting fossil fuels. Here's two, note scale bar, though I have no idea what the rock around it is like regarding water losses: https://www.google.com/maps/@50.9063171,6.4418046,17655m/data=!3m1!1e3?entry=ttu&g_ep=EgoyMDI2MDMwMi4wIKXMDSoASAFQAw%3D%3D https://www.google.com/maps/@50.9063171,6.4418046,17655m/dat... * it's never "just" with things on this scale
nomel 7mo ago
There are exactly zero economically viable pumped water storage systems where water towers are involved. If you do the math for the amount of a mass of water, you'll see why! It's not feasible.
- alexfoo 7mo ago
  Indeed, you can get a sense of the scale on the Dinorwig wikipedia page and the pages it links to. It has a storage capacity of about 9.1GWh. The upper reservoir (https://en.wikipedia.org/wiki/Marchlyn_Mawr https://en.wikipedia.org/wiki/Marchlyn_Mawr) holds 9.2 million cubic meters of water. So 1 million cubic meters of water provides ~1GWh. We can see how that compares in terms of raw GPE (Gravitational Potential Energy): 1 million cubic meters of water = 1E6 * 1E3 kg = 1E9 kg There's roughly a 500m vertical drop between the upper and lower takes at Dinorwig so: 1E9 kg * 500 m * 9.8 m/(s^2) = 4.9E12 J =~ 1.36GWh As for water towers, if you look at something like the Roihuvuori tower in Helsinki (from https://en.wikipedia.org/wiki/Water_tower https://en.wikipedia.org/wiki/Water_tower) which is one of the largest: Height: 52m, Capacity: 12000 cubic meters If we are generous and say that all of the water is stored at the maximum height then: 12000 * 1E3 kg * 52m * 9.8 m/(s^2) =~ 1.7MWh You'd need over 5000 of them to match what Dinorwig can provide.

Pumped hydro energy storage relies on the cheapness of water and existing geology. If you have to build the chambers instead of damming a river it's too expensive. Most of the good spots to have a reservoir are already used. If you have to manufacture the bulk media instead of just using water it's too expensive.

ben_w 7mo ago
Pumped hydro doesn't need a river, "just"* rock which isn't water porous and some nearby body of water (lake, sea, whatever). The economics works out even if you were lifting concrete blocks rather than water, hence why you get pictures like this: https://en.wikipedia.org/wiki/File:Energy_Vault_Test_Tower_2021.jpg https://en.wikipedia.org/wiki/File:Energy_Vault_Test_Tower_2... The argument against lifting concrete is that you can dig a hole in the ground an pump water in/out of it for more reliability and lower cost than having a crane lift and lower concrete, and it's easy to make it much bigger both horizontally and vertically, so why bother. But it does appear to be economical even with that, and water is cheaper. We make lots of holes in the ground on a regular basis, including for extracting fossil fuels. Here's two, note scale bar, though I have no idea what the rock around it is like regarding water losses: https://www.google.com/maps/@50.9063171,6.4418046,17655m/data=!3m1!1e3?entry=ttu&g_ep=EgoyMDI2MDMwMi4wIKXMDSoASAFQAw%3D%3D https://www.google.com/maps/@50.9063171,6.4418046,17655m/dat... * it's never "just" with things on this scale

nomel 7mo ago

There are exactly zero economically viable pumped water storage systems where water towers are involved. If you do the math for the amount of a mass of water, you'll see why! It's not feasible.

alexfoo 7mo ago
Indeed, you can get a sense of the scale on the Dinorwig wikipedia page and the pages it links to. It has a storage capacity of about 9.1GWh. The upper reservoir (https://en.wikipedia.org/wiki/Marchlyn_Mawr https://en.wikipedia.org/wiki/Marchlyn_Mawr) holds 9.2 million cubic meters of water. So 1 million cubic meters of water provides ~1GWh. We can see how that compares in terms of raw GPE (Gravitational Potential Energy): 1 million cubic meters of water = 1E6 * 1E3 kg = 1E9 kg There's roughly a 500m vertical drop between the upper and lower takes at Dinorwig so: 1E9 kg * 500 m * 9.8 m/(s^2) = 4.9E12 J =~ 1.36GWh As for water towers, if you look at something like the Roihuvuori tower in Helsinki (from https://en.wikipedia.org/wiki/Water_tower https://en.wikipedia.org/wiki/Water_tower) which is one of the largest: Height: 52m, Capacity: 12000 cubic meters If we are generous and say that all of the water is stored at the maximum height then: 12000 * 1E3 kg * 52m * 9.8 m/(s^2) =~ 1.7MWh You'd need over 5000 of them to match what Dinorwig can provide.