Good read from @JulianSpector on how batteries performed during #California's recent capacity crisis. In a nutshell, they did great but we need more. And 2-4 hour duration is just fine (for now) rather than the long-duration some have insisted we need. https://www.greentechmedia.com/squared/storage-plus/how-did-energy-storage-perform-in-its-biggest-test-so-far

A fascinating aspect of #California's capacity crisis is that batteries were finally dispatched to time-shift solar. To date, they've mostly been used for ancillary services, not peak or ramping services. The graph below shows batteries discharging from 6-8pm to meet the moment!

As @JulianSpector points out, this same pattern -- a 2-hour discharge from 6-8pm -- repeated the following days as well. This suggests that 2-4 hour storage is where the focus should be for now. Longer-duration batteries would likely be underutilized on our system today.

Make no mistake, we will need long-duration storage in the future we shift an increasing amount of excess, cheap solar to power our system at night. But we can do so at a point when battery costs are much lower than they are today.