7 ms·

Worth pointing out here that nobody is planning to do large scale 12-hour storage with lithium ion batteries. Even leaving out better battery chemistries for t

by rgmerk 4y ago

Worth pointing out here that nobody is planning to do large scale 12-hour storage with lithium ion batteries. Even leaving out better battery chemistries for the moment, you can use pumped hydro (even with seawater - some of the UAE’s highest mountains are near the coast) and thermal storage (you might think you don’t need it in such a hot place but you’ve still got to bake bread etc etc).

0cf8612b2e1e 4y ago
Outside of the enormous engineering pitfalls of dealing with seawater, you would even get a slight boon in energy storage because it is 2-3% more dense than pure water.
PaulDavisThe1st 4y ago
Word on the street is that locations for pumped hydro are, for a variety of reasons that vary by locale, pretty much maxed out already.
- speed_spread 4y ago
  Pumped hydro doesn't require mountains, you can also dig an underground reservoir.
  - defrost 4y ago
    Pumped hydro requires a large volume of fluid and a height difference. Valleys are useful as they provide a large volume that can be capped with relative ease. An underground reservoir requires a large volume to be excavated (or a pre existing cave system) and a deeper chamber again for the turbines to powered by the fall .. to yet another deeper underground reservoir. I'm not saying this is impossible, I stating that as an engineering venture (actual civil engineering not software "engineering") there are some real challenges and greater ones than using existing topography. You're hand waving a lot away with your comment.
  - rgmerk 4y ago
    To be honest I'm pretty doubtful the economics of excavating a reservoir are going to work. It needs to be very big and very deep, which is going to be very expensive unless you're planning to go all Edward Teller (don't go all Edward Teller).
- pydry 4y ago
  You're mixing it up with hydroelectric dams which need a river. Pumped hydro needs two close bodies of water at different heights. That geography is very very common.
  - robertlagrant 4y ago
    > That geography is very very common. Could you provide some more info for this? My understanding was a lot of the sites that could do this, have done. If that's not the case it'd be good to see what the real picture is.
    - Schroedingersat 4y ago
      There's no point if you don't have energy to store. Only 1% of potential sites need to be developed https://re100.eng.anu.edu.au/global/ https://re100.eng.anu.edu.au/global/ Probably won't happen because batteries will be even cheaper by the time much of it is developed.
      - robertlagrant 4y ago
        That link is what makes me concerned when talking on these topics. Far too much certainty and trust seem to be derived from and placed in such studies. In this case, from the study: > None of the PHES sites discussed in this study have been the subject of geological, hydrological, environmental, heritage and other studies, and it is not known whether any particular site would be suitable. The commercial feasibility of developing these sites is unknown.
        Schroedingersat 4y ago
        > makes me concerned There it is. Always so concerned" about whatever imaginary downside alternatives have, but completely credulous about nuclear which has failed over and over again. You're claiming without any evidence whatsoever that at least 99% of geographically appropriate sites are unusable.
- adgjlsfhk1 4y ago
  yes and no. we've put dams in the obvious places, but we're mostly using them as generation rather than storage. switching them to be run as batteries will massively expand the amount of grid storage.
  - robertlagrant 4y ago
    Pumped hydro is storage by definition, is it not?
    - adgjlsfhk1 4y ago
      A dam in a river can either be used as generation (if you always run it) or as storage if you vary the output. Most pumped hydro is already storage, but most hydro currently isn't pumped.
      - rgmerk 4y ago
        And it’s worth pointing out here that conventional hydro is being optimised in some places for a world with a lot of wind and solar in the grid. In a nutshell, you put in more generators to maximise your peak generation capacity, and operate them only when required.
      - robertlagrant 4y ago
        Ah, understood. But this isn't to do with renewable power storage at this point, just using artificial lakes as separate peak power storage?

by rgmerk 4y ago

0cf8612b2e1e 4y ago

Outside of the enormous engineering pitfalls of dealing with seawater, you would even get a slight boon in energy storage because it is 2-3% more dense than pure water.

PaulDavisThe1st 4y ago

Word on the street is that locations for pumped hydro are, for a variety of reasons that vary by locale, pretty much maxed out already.

speed_spread 4y ago
Pumped hydro doesn't require mountains, you can also dig an underground reservoir.
- defrost 4y ago
  Pumped hydro requires a large volume of fluid and a height difference. Valleys are useful as they provide a large volume that can be capped with relative ease. An underground reservoir requires a large volume to be excavated (or a pre existing cave system) and a deeper chamber again for the turbines to powered by the fall .. to yet another deeper underground reservoir. I'm not saying this is impossible, I stating that as an engineering venture (actual civil engineering not software "engineering") there are some real challenges and greater ones than using existing topography. You're hand waving a lot away with your comment.
- rgmerk 4y ago
  To be honest I'm pretty doubtful the economics of excavating a reservoir are going to work. It needs to be very big and very deep, which is going to be very expensive unless you're planning to go all Edward Teller (don't go all Edward Teller).
pydry 4y ago
You're mixing it up with hydroelectric dams which need a river. Pumped hydro needs two close bodies of water at different heights. That geography is very very common.
- robertlagrant 4y ago
  > That geography is very very common. Could you provide some more info for this? My understanding was a lot of the sites that could do this, have done. If that's not the case it'd be good to see what the real picture is.
  - Schroedingersat 4y ago
    There's no point if you don't have energy to store. Only 1% of potential sites need to be developed https://re100.eng.anu.edu.au/global/ https://re100.eng.anu.edu.au/global/ Probably won't happen because batteries will be even cheaper by the time much of it is developed.
    - robertlagrant 4y ago
      That link is what makes me concerned when talking on these topics. Far too much certainty and trust seem to be derived from and placed in such studies. In this case, from the study: > None of the PHES sites discussed in this study have been the subject of geological, hydrological, environmental, heritage and other studies, and it is not known whether any particular site would be suitable. The commercial feasibility of developing these sites is unknown.
      - Schroedingersat 4y ago
        > makes me concerned There it is. Always so concerned" about whatever imaginary downside alternatives have, but completely credulous about nuclear which has failed over and over again. You're claiming without any evidence whatsoever that at least 99% of geographically appropriate sites are unusable.
adgjlsfhk1 4y ago
yes and no. we've put dams in the obvious places, but we're mostly using them as generation rather than storage. switching them to be run as batteries will massively expand the amount of grid storage.
- robertlagrant 4y ago
  Pumped hydro is storage by definition, is it not?
  - adgjlsfhk1 4y ago
    A dam in a river can either be used as generation (if you always run it) or as storage if you vary the output. Most pumped hydro is already storage, but most hydro currently isn't pumped.
    - rgmerk 4y ago
      And it’s worth pointing out here that conventional hydro is being optimised in some places for a world with a lot of wind and solar in the grid. In a nutshell, you put in more generators to maximise your peak generation capacity, and operate them only when required.
    - robertlagrant 4y ago
      Ah, understood. But this isn't to do with renewable power storage at this point, just using artificial lakes as separate peak power storage?