“As far as California having excess grid capacity at night, you must have missed all those advisories in August and September telling people in California NOT to charge there EVs at night because the grid could not keep up with people using AC and charging EVs at the same time. “
Thanks for providing a link that falsifies your post
THE advisory IS FOR 4PM TO 9PM. That leaves 9PM to 4PM with excess capacity.
Apparently, you cannot charge them during the day or at night.