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Cool. Technology like liquid air, compressed air, electrolysed hydrogen etc. has a very different use case to lithium ion batteries. Batteries are good for sho

Cool. Technology like liquid air, compressed air, electrolysed hydrogen etc. has a very different use case to lithium ion batteries. Batteries are good for short cycle times, if you need to balance your grid and even to some extent if you need to correct for diurnal patterns, you want batteries. The high capital cost is compensated for by the high round-trip efficiency. For seasonal storage or even inter-year storage, batteries do not work. You spend a fortune on them and then cycle the system once a year or less. The advantage of these other systems is you can decouple three elements: The conversion in The storage The conversion out and match the capacity of each to what you need. For long term storage of hydrogen for instance, you want relatively small electrolysers with fast response times so that you can use excess electricity during sunny windy periods, a massive geological storage that can hold a year+ of production, and modestly sized fuel cells to turn it back into electricity in the winter (in Europe anyway) with good heat recovery. In the case of this technology, you can again size the charging, discharging, and storage separately. The scaling for tanks is much cheaper than batteries. Flow batteries use a similar idea by separating out the charging/discharging membrane and the electrolyte tanks but I don't think anyone has gotten satisfactory performance from them yet. You can't build a lithium ion battery where you specify the storage capacity separately from the charge and discharge rates with anything like that kind of freedom. You can adjust the battery chemistry of course but nothing like the same.

sitkack 6y ago
This is why pumped hydro using existing dams is so nice. I think constructing enough storage to handle months of lower solar output will be difficult. Phase locking human activity, including economic to the energy cycle would obviate the need for many technical solutions. We should just hibernate.
- Mvandenbergh 6y ago
  Pumped hydro using existing dams is brilliant and should be maximally exploited but we already have dams on all the really good sites. We can improve by adding the pump-up stage to many of them but there is simply no scope for massive expansion in total reservoir / energy storage capacity.

sitkack 6y ago

This is why pumped hydro using existing dams is so nice. I think constructing enough storage to handle months of lower solar output will be difficult. Phase locking human activity, including economic to the energy cycle would obviate the need for many technical solutions. We should just hibernate.

Mvandenbergh 6y ago
Pumped hydro using existing dams is brilliant and should be maximally exploited but we already have dams on all the really good sites. We can improve by adding the pump-up stage to many of them but there is simply no scope for massive expansion in total reservoir / energy storage capacity.