California residents may be asked to reduce electricity use this week to avert rolling blackouts amid a heat wave that threatens to strain the state’s power grid.

The California Independent System Operator, the nonprofit that runs the grid, said Tuesday that it should have enough electricity to meet demand and avert outages.

But disruptions such as wildfires that burn transmission lines, mechanical failure at power plants or other unexpected problems could lead to the first “Flex Alert” of the year. If an alert is called, people would be asked to voluntarily cut electricity use from 4 to 9 p.m. Wednesday and Thursday, said Anne Gonzales, a spokeswoman for the grid operator.

“We don’t expect rotating outages this week,” Gonzales told the Bay Area News Group. “But we are going to see some tight supplies. Our main message is one of conservation.”

Officials with the nonprofit also ordered power plant operators across the state to put off scheduled maintenance on the facilities and transmission lines Tuesday through Friday to keep as much electricity flowing as possible.

Triple-digit temperatures are expected across California and much of the U.S. West all week.

During a heat wave last August, California experienced rolling blackouts over two days, affecting hundreds of thousands of people for several hours. They were the first in 19 years, when blackouts in 2001 contributed to the recall of former Gov. Gray Davis.

Gonzales said the state’s power grid is better prepared this year than last year. California has roughly 3,000 to 3,500 megawatts of additional electricity — enough for 2.2 million to 2.6 million homes — coming online by this summer, she said.

If the grid operator calls a Flex Alert on Wednesday or Thursday, residents would be asked to set thermostats to 78 degrees or higher, avoid using major appliances and turn off unnecessary lights, the Bay Area News Group said.