Graph showing the timing imbalance between peak demand and renewable electricity production
The Duck Curve
Blue curve: Demand for electrical power Orange curve: (the duck curve) supply of electrical power from dispatchable sources, Gray curve: supply of solar electrical power Data is for the State of California on October 22, 2016 (a Saturday),[1] a day when the wind power output was low and steady throughout the day. The orange curve rises steeply from 17:00 to 18:00 as the sun sets, requiring about 5 gigawatt of generating capacity from dispatchable sources to come on line within one hour.