2024 Eclipse Effect on Solar in California

[miimura]

I saw lots of people posting their solar production charts online that were near the path of totality. California was only about 30% occluded, so the effect was less. Here is my solar production chart from Silicon Valley.

The effect on the California grid was similar.

The interesting thing is that grid scale batteries filled in most of the shortfall caused by the eclipse. It looks like about +2.7GW for the eclipse and +5GW for the evening peak around 8pm. Peak charging looks to be about -3.8GW right after the eclipse.

 

[fhteagle]

ERCOT had a fun day, according to this:

https://www.eia.gov/electricity/gridmonitor/dashboard/electric_overview/balancing_authority/ERCO

Looks like a ~9GW solar dip out of ~53GW system load, picked up mostly by methane burning generation, with a hint of coal and battery to boot. Glad it happened in the spring calm, and not the summer peak when their loads are ~30GW higher...

 

[wwu123]

Aren't cool spring days the time when spot energy prices tend to go negative in California, i.e. abundance of solar and lack of energy need for heating/cooling? Makes total sense to store the excess in batteries rather than "selling" at a negative price - well, that's true in general, but specifically the eclipse uniquely allowed the batteries to get two cycles in one day, which is great since normally can only cycle once a day.

Not sure if I'm reading the CAISO data correctly, but I think it's saying spot prices this morning (day after the eclipse) are already negative for most of California even around 8am, sure to be even more negative at mid-day. I don't know if CAISO can show historic price data, but I hope the grid battery owners at least got positive prices discharging during the eclipse.