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> Pumped hydro is great where you can build it and it is cost superior to batteries Given the dramatic price decline of LFP cells in the past year, I'm not sur

> Pumped hydro is great where you can build it and it is cost superior to batteries Given the dramatic price decline of LFP cells in the past year, I'm not sure this is still the case.

toomuchtodo 2y ago
I cannot speak authoritatively as to whether the LFP cell cost decline curve has enabled stationary storage to be cost superior in all cases compared to both short and long duration pumped hydro, hence the caveat. I have no doubt we'll get there, just not sure we're there yet. Probably something for Lazard's next LCOE report, to act as a canonical reference for such discussions. https://www.lazard.com/research-insights/levelized-cost-of-energyplus/ https://www.lazard.com/research-insights/levelized-cost-of-e...
bryanlarsen 2y ago
The cost difference depends on number of cycles. If you fill and empty your storage daily, batteries are way cheaper. If you fill and empty annually, pumped storage is way cheaper.
- pfdietz 2y ago
  Annual (or seasonal) cycling is also bad for pumped storage. Chemical storage, like hydrogen, becomes much cheaper for that storage case.
  - bryanlarsen 2y ago
    Hydrogen is a very poor long term storage. It either uses very expensive tanks or it leaks away. It's also a couple of orders of magnitude more expensive.
    - pfdietz 2y ago
      No, hydrogen is excellent for long term storage. It is stored underground. "Couple of orders of magnitude more expensive" is not correct. For long term storage, the capex per energy storage capacity dominates, and the cost of underground storage caverns (especially solution mined in salt) is very cheap, an order of magnitude cheaper per unit of stored energy than reservoirs for water.
      - bryanlarsen 2y ago
        It doesn't matter how cheap the storage is if the hydrogen costs $3/kg.
        pfdietz 2y ago
        You seem to be changing your argument there. It absolutely does matter. If one is cycling the storage system annually, $3/kg for hydrogen becomes a minor part of the cost. The cost of this input is proportional to the number of charge/discharge cycles over the timescale indicated by the discount rate, and for annual storage that's not very many. It's a common mistake to think that the importance of round trip efficiency for diurnal storage carries over to annual storage.

> Pumped hydro is great where you can build it and it is cost superior to batteries Given the dramatic price decline of LFP cells in the past year, I'm not sure this is still the case.

toomuchtodo 2y ago

I cannot speak authoritatively as to whether the LFP cell cost decline curve has enabled stationary storage to be cost superior in all cases compared to both short and long duration pumped hydro, hence the caveat. I have no doubt we'll get there, just not sure we're there yet. Probably something for Lazard's next LCOE report, to act as a canonical reference for such discussions. https://www.lazard.com/research-insights/levelized-cost-of-energyplus/ https://www.lazard.com/research-insights/levelized-cost-of-e...

bryanlarsen 2y ago

The cost difference depends on number of cycles. If you fill and empty your storage daily, batteries are way cheaper. If you fill and empty annually, pumped storage is way cheaper.

pfdietz 2y ago
Annual (or seasonal) cycling is also bad for pumped storage. Chemical storage, like hydrogen, becomes much cheaper for that storage case.
- bryanlarsen 2y ago
  Hydrogen is a very poor long term storage. It either uses very expensive tanks or it leaks away. It's also a couple of orders of magnitude more expensive.
  - pfdietz 2y ago
    No, hydrogen is excellent for long term storage. It is stored underground. "Couple of orders of magnitude more expensive" is not correct. For long term storage, the capex per energy storage capacity dominates, and the cost of underground storage caverns (especially solution mined in salt) is very cheap, an order of magnitude cheaper per unit of stored energy than reservoirs for water.
    - bryanlarsen 2y ago
      It doesn't matter how cheap the storage is if the hydrogen costs $3/kg.
      - pfdietz 2y ago
        You seem to be changing your argument there. It absolutely does matter. If one is cycling the storage system annually, $3/kg for hydrogen becomes a minor part of the cost. The cost of this input is proportional to the number of charge/discharge cycles over the timescale indicated by the discount rate, and for annual storage that's not very many. It's a common mistake to think that the importance of round trip efficiency for diurnal storage carries over to annual storage.