This applies to Photovoltaics only, not to wind or concentrated solar, and looks like something that is pretty specific to California's energy mix and policies.

This applies to Photovoltaics only, not to wind or concentrated solar, and looks like something that is pretty specific to California's energy mix and policies. If we replace fossil fuels during the day and turn on hydro and other during the night, I still think the duck curve is not an argument against adding much more PV capacity.