Managers of California's power grid were anticipating another day of high electricity demand Saturday, one day after initiating rolling blackouts for the first time since 2001.
After a day that saw triple-digit temperatures in many parts of the state, the California Independent System Operator declared a Stage 3 Emergency at 8 p.m. Friday and directed utility companies to initiate rotating outages throughout California.
San Diego Gas & Electric announced at 7 p.m. that CAL-ISO had directed it to begin rotating, one-hour service interruptions in San Diego and Orange counties.
The utility company announced on Twitter at 8:20 p.m. that its rotating outages had ended for the night, and all 58,700 customers impacted had their power restored.
The statewide emergency was lifted shortly before 10 p.m., and power was restored.
"A Stage 3 Emergency is declared when demand outpaces available supply," Cal-ISO said in a statement. The order was declared after "extreme heat drove up electricity demand across California, causing the ISO to dip into its operating reserves for supply to cover demand."
"Although a Stage Emergency is a significant inconvenience to those affected by rotating power interruptions, it is preferable to manage an emergency with controlled measures rather than let it cause widespread and more prolonged disruption," Cal-ISO said.
A Flex Alert was issued earlier in the day, urging residents statewide to conserve electricity between 3 and 10 p.m. to avoid overloading the power system.
Cal-ISO offered a series of tips, including:
— Turning off unnecessary lights;
— Using major appliances before 3 p.m. and after 10 p.m.;
— Setting air conditioner thermostats to 78 degrees or higher;
— Using fans; and
— Keeping drapes drawn.
According to CAL-ISO, the state's available capacity for Saturday was 49,184 megawatts, with peak demand expected to be 46,372 megawatts.
