There is some limited evidence that California’s solar “curtailment” problem is receding on battery deployment. Curtailment, or the involuntary reduction of output of solar or wind generation due to system oversupply, could restrict renewables penetration. Indeed, most renewables and electricity experts continue to warn that solar penetration will face hard ceilings without long-duration storage availability. It seems, however, that CAISO is successfully reducing solar and wind curtailment – at least for now. While batteries are only one variable in extraordinarily complex electricity markets, California’s experience suggests that the rest of America could soon see more at-scale battery deployment, mitigating renewables’ “intermittency” problems and increasing their share of the fuel mix. We’ll know more after data from California’s low baseload Autumn comes in.

California’s Solar Curtailment Trends

According to CAISO statistics through June, YTD solar generation is up 18% while YTD curtailment is down by about 9%. In other words, solar operators have been able to produce more without curtailing production.