The mix of energy sources used for power generation in California this summer changed from last summer, as renewables and imported electricity offset lower natural gas use. During summer 2016 (June, July, and August) thermal generation (almost all from natural gas) in the area serviced by the California Independent System Operator (CAISO) was down 20% from the previous summer, while generation from hydroelectricity, other renewables, and electricity imports was higher than the same period last year.
Source: Today In Energy