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This article is about storing energy generated using renewables in reservoirs; not about tapping into geothermal energy. The issue with geothermal is not that

This article is about storing energy generated using renewables in reservoirs; not about tapping into geothermal energy. The issue with geothermal is not that the energy isn't there but that getting to it involves a lot of expensive infrastructure. It's cost effective in some parts of the world and not really cost effective (relative to cheaper solutions) in other parts of the world. Using this instead would mean having to drill much less deep (so it's cheaper). You are sill throwing away more than half of the energy you put in though. Geothermal has similar inefficiencies except you get the energy that needs to put in for free. Not so with this solution: you have to generate the energy yourself.

Someone 4y ago
> This article is about storing energy generated using renewables in reservoirs; not about tapping into geothermal energy. I think it’s about both. They plan to create reservoirs that heat water _and_ use them to store warm water. Also for the latter the outside heat source will provide energy. FTA: Enhanced geothermal systems (EGS) get around this geographical limitation by creating artificial reservoirs. Developers create fractures in hot, dry rock formations by drilling into or melting the rock, and then injecting water into the fissures. Production wells bring the heated water up for producing electricity. “For scales necessary to contribute to national or global electricity decarbonization, we need to be able to extract geothermal heat outside of conventional formations,” Ricks says. […] Once these EGS systems are in place, they would be ideal for storing energy as well as producing electricity. Excess wind or solar energy could be used to inject water into the artificial reservoirs
- drewbeck 4y ago
  Yeah that last line is key — they’re not creating heat with the excess energy, they’re pumping water. The article doesn’t have much specifics but the implication is they’re achieving much higher efficiency than if they were doing electricity → heat → electricity
  - Someone 4y ago
    It’s not clear from the article, but I think they’re aiming to do both: create new geothermal sources by drilling (running, I guess, some of the risks of fracking) _and_ storing excess energy as heat in those sources.
    - drewbeck 4y ago
      yeah they're creating geothermal reservoirs to pump with water to then extract steam. any excess energy generated from renewables gets used to pump additional water into the reservoir.

Someone 4y ago

> This article is about storing energy generated using renewables in reservoirs; not about tapping into geothermal energy. I think it’s about both. They plan to create reservoirs that heat water _and_ use them to store warm water. Also for the latter the outside heat source will provide energy. FTA: Enhanced geothermal systems (EGS) get around this geographical limitation by creating artificial reservoirs. Developers create fractures in hot, dry rock formations by drilling into or melting the rock, and then injecting water into the fissures. Production wells bring the heated water up for producing electricity. “For scales necessary to contribute to national or global electricity decarbonization, we need to be able to extract geothermal heat outside of conventional formations,” Ricks says. […] Once these EGS systems are in place, they would be ideal for storing energy as well as producing electricity. Excess wind or solar energy could be used to inject water into the artificial reservoirs

drewbeck 4y ago
Yeah that last line is key — they’re not creating heat with the excess energy, they’re pumping water. The article doesn’t have much specifics but the implication is they’re achieving much higher efficiency than if they were doing electricity → heat → electricity
- Someone 4y ago
  It’s not clear from the article, but I think they’re aiming to do both: create new geothermal sources by drilling (running, I guess, some of the risks of fracking) _and_ storing excess energy as heat in those sources.
  - drewbeck 4y ago
    yeah they're creating geothermal reservoirs to pump with water to then extract steam. any excess energy generated from renewables gets used to pump additional water into the reservoir.