Rolling Blackouts Across California, Riverside County: Update

RIVERSIDE COUNTY, CA — High heat and increased electricity demand prompted the California Independent System Operator to briefly declare a "Stage 3 Electrical Emergency" Friday evening, and rolling power outages began across the state.

"Rotating power interruptions have been initiated to maintain stability of the electric grid," the ISO announced.

A Stage 3 Emergency is declared when electricity demand outpaces available supply. The ISO has dipped into its operating reserves, according to the agency.

"The California ISO is working closely with California utilities and neighboring power systems to manage strain on the grid and to restore the power grid to full capacity. As portions of the grid are restored, local utilities will restore power in a coordinated fashion," the agency said.

According to the ISO, rolling power outages are preferable to widespread and more prolonged disruptions.

The emergency declaration was lifted at 8:54 p.m. after the grid stabilized, however the ISO’s grid operators are "closely monitoring supply and demand during the extreme heat event," the agency said.

About 1,000 megawatts of electricity were taken out of service during the emergency declaration that began at 6:36 p.m.

On Thursday, the ISO issued a Flex Alert, which called on California residents and businesses to conserve electricity between 3 p.m. and 10 p.m. Friday — when demand was expected to peak — in an effort to avoid power outages.

The ISO continues to call on Californians to conserve electricity amid a heat wave that is forecast to last into next week across the SoCal region.

The National Weather Service issued an excessive heat warning that began at noon Friday and will last through 9 p.m. Monday in Southwest Riverside County, the Riverside metropolitan area, the Riverside County mountains, and the San Gorgonio Pass near Banning. In the Coachella Valley, the warning is extended through 10 p.m. Wednesday.

Throughout the heat wave, daytime temperatures in all areas will near or surpass the 100-degree mark. In the Coachella Valley, daytime highs are expected to hover around 115.