Solar and wind power helped the California grid maintain reliability during a challenging summer this year. According to the California Independent System Operator (ISO), grid operators were up against heat waves, historic drought conditions and major wildfires.
The ISO says this summer's highest level of demand reached 45,090 MW at 4:53 p.m. on Sept. 15, 2014. This compares to 45,097 MW set on June 28, 2013, and 46,846 MW on Aug. 13, 2012. The ISO's highest peak on record is 50,270 MW on July 24, 2006.
On a local level, the ISO says southern California set new demand records that underscore the impact from hot temperatures recorded during the summer, especially along the coast.
For example, the San Diego Gas & Electric area experienced record use on Sept. 15 and then topped the next day with an all-time record demand of 4,895 MW. The standing record peak was 4,684 MW set on Sept. 27, 2010.
The Southern California Edison area also experienced heavy loads, reaching 23,266 MW on Sept. 15. According to the ISO, this was just shy of the area's all-time peak of 23,388 MW set on Sept. 7, 2011.
During high demand, grid operators often rely on any and all available resources to help keep the lights on, including renewable energy. However, the ISO says there were 1,628 MW less of in-state hydropower this summer because of historic drought conditions.
Meanwhile, wind and solar power facilities have performed well so far this year. In fact, wind set an ISO production record on April 12, with 4,768 MW, and solar production hit a new peak on Sept. 29, with 4,903 MW.
The ISO says it has about 5,900 MW of wind resources and about 5,500 MW of utility solar resources connected to the grid. Counting all renewable resources (including small hydro, biomass, biogas and geothermal), the ISO notes that it has 15,226 MW of clean power on the grid.