The California Independent System Operator (ISO) has issued a statewide Flex Alert for Wednesday, Aug. 17, from 4 p.m. to 9 p.m.
A Flex Alert is a call for voluntary electricity conservation.
State energy regulators say hot weather across the state is increasing the demand for electricity as more people turn on their air conditioners, and that's putting the squeeze on available power supplies.
Californians are being asked to conserve electricity, especially during the late afternoon and early evening hours when the power grid is most stressed due to higher demand and less solar energy.
The California ISO suggests people use major appliances like washers, dryers and dishwashers before 4 p.m., precool your home by setting the thermostat to 72 degrees, and adjust blinds and drapes to cover windows. After 4 p.m., set the thermostat to 78 degrees or higher, avoid using major appliances and turn off all unnecessary lights.