The California Independent System Operator Corporation (CAISO) has moved up the start time of Wenesday's Flex Alert, a call to residents to conserve energy to avoid rotating outages as a heat wave sweeps across much of the state.
The statewide alert will be in effect from 2 to 9 p.m., an hour earlier than typical alerts due to the extra need for a reduction in energy usage, CAISO said.
"The ISO understands that conserving electricity is difficult, especially for those working from home or who have children attending school at home. But if all Californians are thoughtful about their energy use, even in small ways, power interruptions can be avoided or limited," the CAISO said in a statement.
Flex Alerts are issued when the electricity grid is overtaxed due to high temperatures, the ISO said. It is a voluntary call on residents to conserve electricity when demand is at its peak.
Adding to California's energy supply limits, Tropical System Elida off the Pacific Coast has increased cloud cover, reducing the state's ability to generate electricity.
If enough energy is not conserved, CAISO issue a Stage 3 Emergency, ordering utility companies to begin rotating power outages for several circuits at a time in order to prevent major blackouts across the grid.
Just after 4 p.m. CAISO said it didn't anticipate any forced outages Wednesday.
San Diego Gas & Electric has been advised rotating outages can occur several times during the recent heat wave. Rotating outages occurred at least twice but was also avoided twice due to the conservation efforts of San Diegans, the utility said.
Consumers should conserve electricity by turning off unnecessary lights, not using major appliances and setting air conditioner thermostats to 78 degrees or higher, especially in the late afternoon and early evening when the grid is most stressed, the ISO said.
"These conservation measures can help the power grid during a time of tight demand and supply, and avoid power interruptions," the ISO said.
More energy-saving tips can be found on the FlexAlert website.
The National Weather Service said residents should brace for a "dangerous long-duration heat wave" that will impact almost all of California for several days with little relief. An excessive heat warning will go into effect at 12 p.m. Friday and last through at least 9 p.m. Monday for most of Southern California and until 9 p.m. Wednesday for much of Northern California.
A Flex Alert will remain in effect through Thursday.