The operator of California's power grid is calling for voluntary conservation of electricity as an intense heat wave broils the state for the second time this week.
The California Independent System Operator says the so-called Flex Alert will be in effect on Friday from 1 to 10 p.m. The ISO called for the same action on Tuesday.
Energy demand for the day is forecast to exceed 48,000 megawatts, which would be the highest demand on the grid so far this year.
Officials urge consumers to particularly conserve in the late afternoon because that's when air conditioners typically at peak use.
Major appliances should be used before or after the Flex Alert period and air conditioners should be set at 78 degrees or higher.