As temperatures rise, California power grid manager tells generators to keep plants humming

·1 min read
Renée C. Byer/Sacramento Bee file

The temperatures are about to soar and California’s electricity supplies are about to get tight.

The California Independent System Operator, or ISO, which runs the state’s power grid, told generators and transmission-line operators Friday to delay any scheduled maintenance.

The notice goes into effect from Monday through Thursday, from noon to 10 p.m. each day, when temperatures are forecast to surpass 100 degrees across much of the state.

“Avoid actions which may jeopardize generation and/or transmission availability,” the organization said.

Although the ISO hasn’t yet issued a call for conservation, the notice illustrates the fragility of California’s grid. Two years ago the state endured two nights of rolling blackouts during a 110-degree heat storm that engulfed much of the West. The power outages exposed the grid’s vulnerabilities during early-evening hours — when solar energy supplies fade but homeowners are still cranking their air conditioners. Solar can make up one-third or more of California’s electricity supply during summer.

Since then state officials have scrambled to fortify the grid, requiring PG&E Corp. and other utilities to line up additional power supplies. California is also promoting the development of “battery farms,” facilities with industrial-sized batteries that can store unused electricity generated during the day for use during those evening hours.

While that’s helped, state officials have warned that supplies remain tight and blackouts are possible this year. Drought is erasing much of California’s hydro power, putting an extra squeeze on supplies.

Next week is shaping up as one of the hottest of the year, with the high temperature forecast to peak at 104 on Tuesday, according to the National Weather Service.