3 ms·

This press release doesn't say anything about system efficiency. If it was high they'd be promoting that fact. Since it involves refrigeration it's probably qui

• rsynnott 5y ago
  They claim 70%: https://en.wikipedia.org/wiki/Cryogenic_energy_storage#Efficiency https://en.wikipedia.org/wiki/Cryogenic_energy_storage#Effic... > That makes me wonder why they went with this system. Cost, presumably. The stated figures would give $300/kWh, which seems to be about where the all-in cost for lithium ion facilities lands, but this would likely have a longer lifespan.
  • Gibbon1 5y ago
    Offhand impression. With thermal storage systems. Round trip efficiency numbers range from really bad at 50%. To really good at 80%. Batteries are probably 80-90 percent efficient. Notably to me is that cost per mega watt hour varies a lot more than two to one. Which says to me energy storage is economically feasible using a number of different technlogies.
    • rsynnott 5y ago
      I mean, yes. In general, the problem these systems are trying to solve is "ugh, we have too much electricity right now, why can't we use it later" (in particular, areas with a lot of wind generation often have to stop the turbines spinning). At time of storage, the energy is essentially free (or of negative value, really; in the absence of storage the excess energy is a _problem_) so efficiency of storage is much less important than facility cost per MW.