California Grid to Maintain Reliability Despite Drought

Despite a drought that has lowered hydroelectric generation in California, the bulk power system in the state is not expected to lose grid reliability this summer, according to the North American Electric Reliability Corporation (NERC) and reported by the US Energy Information Administration (EIA).

Overall, NERC expects more than 72 GW of electric generating capacity to be available this summer in the part of the electric grid covering much of California. Summer electricity demand is expected to peak at nearly 53 GW, resulting in a reserve margin of 38 percent for the region.

Since early 2014, much of California has experienced extreme or exceptional drought. Last year was the warmest year in California’s history, and 2015 is on pace to be even warmer.

Despite lower than normal summer water runoff, California likely has enough electric generating capacity from other sources to make up for the loss of hydroelectric generation. Available hydroelectric summer capacity within the California Independent System Operator (CAISO) grid was derated by 3,118 MW, according to NERC’s 2015 assessment of electric grid reliability, which was conducted this past spring. This drop in hydroelectric capacity has been partially offset by more than 2,000 MW of new renewable capacity that has come online in the state since June 2014. Increased generation from natural gas generators and increased electricity imports from surrounding areas are also expected to make up for the reduced in-state hydroelectric generation.

From January 2014 to April 2015, hydroelectricity accounted for an average of 9 percent of the state’s monthly generation.