Sun sets on Fort Rosecrans National Cemetery on Wreaths Across America Day.
Sunny warm days will be a challenge for the energy grid over Labor Day weekend. Photo by Chris Stone

A Flex Alert calling for voluntary conservation to reduce strain on the state’s electricity grid will continue until at least Friday afternoon as the San Diego heat wave goes on.

Responding to the heat wave that has driven up temperatures and demand for air conditioning, the California Independent System Operator – which manages the state’s power grid – issued the first Flex Alert of the week Wednesday, urging residents to reduce electricity use from 4 to 9 p.m.

The alert worked, and the state avoided any involuntary blackouts. Another Flex Alert took effect at 4 p.m. Thursday, again set through 9 p.m. With high heat baking all of Southern California, Cal-ISO opted to issue another Flex Alert for Friday.

“Flex Alerts have been resulting in some helpful conservation and grid operators and an emergency proclamation from Gov. Gavin Newsom, requested by the ISO, has also freed up some additional resources,” according to the operator. “… The Flex Alert covers that time of day when the grid is most stressed from higher demand and less solar energy.”

Cal-ISO has warned that more Flex Alerts are likely to be posted during the duration of the heat wave, particularly on Sunday and Monday, which are expected to have the highest electricity demand.

“With excessive heat in the forecast across much of the state and Western U.S., the grid operator is expecting high electricity demand, primarily from air conditioning use, and is calling for voluntary conservation steps to help balance supply and demand,” according to Cal-ISO.

During the alerts, residents are urged to save power by:

  • setting thermostats to 78 degrees or higher;
  • avoiding use of major appliances;
  • turning off unnecessary lights; and
  • avoiding charging electric vehicles.

Residents are also advised to pre-cool their homes as much as possible and close blinds and drapes to keep interiors cool.

A Flex Alert is the lowest-level notification issued by Cal-ISO, but if voluntary conservation fails to cut strain on the power grid, the agency could move into a series of emergency alerts that could ultimately lead to rolling blackouts.

– City News Service