Updated at 8:17 PM Sunday, Sept. 23
Some sort of fluctuation in the statewide power grid resulted in an order to San Diego’s electric utility to reduce power consumption, and up to 90,000 San Diego Gas & Electric customer accounts lost power Sunday afternoon.
The utility said on its Twitter feed that it had been ordered to “shed load” by the statewide power authority, and reduce demand for power by 150 megawatts.
Officials at the California Independent System Operator near Sacramento, which oversees the distribution of power to about 80 percent of California, said they were aware of the SDGE report, but they were still assessing the situation. They told City News Service they were not clear on what was happening.
At 2:45 p.m., SDGE said it had cut power to 3,140 accounts in Claremont, 2,154 accounts on the south and east sides of Escondido, and 1,586 in the Fallbrook and Bonsall areas.
Most of the other areas affected were in Encinitas and Escondido. Other outages were near Fallbrook.
On its Twitter feed, the utility said its call center was getting large numbers of calls. But phones were unanswered at the SDGE media office, and other than the Tweet there was no official reports of unusual problems.
Power was restored about 3 p.m., CalISO spokeswoman Anne Gonzales said.
“At 11:53 a.m., a substantial generator in San Diego went down,” Gonzales said. “When something like that happens, other lines can get overloaded.
“Because it was hot in San Diego and there was a lot of demand at that time, we interrupted service on some lines to keep other lines from overloading,” Gonzales said. “We had to redirect some things to get things under control and prevent a larger outage.”
A megawatt impacts about 650 customers, according to Gonzales. That means if every home or business in the 150-megawatt area taken off the grid today was affected, as many as 97,500 customers could have been blacked out during the outage.
California Highway Patrol officers said vehicles were speeding through intersections with disabled signals in the eastern part of Oceanside.
In Claremont, a movie theater was blacked out and evacuated, according to a San Diego television report.
CalISO matches electric demand to available power from generating companies. Its automated website said the state had 48,000 megawatts of power available at midafternoon.
A spokeswoman for Southern California Edison said its system in Orange, Riverside and Los Angeles counties was not affected.
City News Service contributed to this article.
