The California Independent System Operator Corporation (ISO) has issued its first Flex Alert of the summer on Friday to urge to conserve energy as a heat wave sweeps across much of the state.
The statewide alert will be in effect from 3 to 10 p.m. on Friday when temperatures are expected to surge about 10 degrees above average for this time of year in many California counties.
Flex Alerts are issued when the electricity grid is overtaxed due to high temperatures, the ISO said. It is a voluntary call on residents to conserve electricity when demand is at its peak.
"Prolonged heat over several consecutive days is expected to drive electricity demand higher, as nighttime temperatures are also forecast to be above average," the agency said.
Adding to California's energy supply limits, Tropical System Elida off the Pacific Coast has increased cloud cover, reducing the state's ability to generate electricity.
Consumers should conserve electricity by turning off unnecessary lights, not using major appliances and setting air conditioner thermostats to 78 degrees or higher, especially in the late afternoon and early evening when the grid is most stressed, the ISO said.
"These conservation measures can help the power grid during a time of tight demand and supply, and avoid power interruptions," the ISO said.
More energy-saving tips can be found on the FlexAlert website.
The National Weather Service said residents should brace for a "dangerous long-duration heat wave" that will impact almost all of California for several days with little relief. An excessive heat warning will go into effect at 12 p.m. Friday and last through at least 9 p.m. Monday for most of Southern California and until 9 p.m. Wednesday for much of Northern California.