‘We’re heading to the worst part of this heat wave’; Californians brace for a scorching Tuesday afternoon

OAKLAND — The temperature gauge read 108 at noon, Livermore was baking once again Tuesday under a record heat wave that has blanketed the state, triggering a surge in demand on the California’s power grid that pushed the electrical circuits to their limits.

Across the San Francisco Bay Area, thousands of residents sweated it out in their homes and businesses without power as the heat overwhelmed transformers in Santa Rosa, San Ramon, Livermore and other communities.

“Less than 10,000 customers in the entire Bay Area are being impacted by a power outage,” PG&E said in a news release. “That’s mostly due to an outage that started in 12:15 in the East Bay impacting about 4,900 customers in Pleasanton and Dublin.  Crews are looking into the cause and working to restore power safely and as quickly as possible.”

BART slowed commute trains to make sure the overheated tracks remained stable. The Novato Unified School District went to a modified class schedule and Oakland turned eight city libraries into cooling centers.

Gov. Gavin Newsom issued a plea for energy conservation.

 “This heat wave is on track to be the longest and the hottest on record for the state and many parts of the west for the month of September,” he said. “We’re heading to the worst part of this heat wave. The risk for outages if real and it’s immediate. These triple digit temperatures throughout our state are leading to not surprising record demand on the energy grid.”

For a second straight day, temperatures records were being challenged or topped. Forecasters predicted the temperature would reach 113 in both Concord and Livermore to set new records.

Officials say the real crisis point would be Tuesday afternoon.

“Extreme heat will continue through the remainder of the workweek though Tuesday is currently anticipated to be the hottest day,” the weather service warned.

As people crank up their air conditioners, the state forecasted record levels of energy use, said Elliot Mainzer, president of California Independent System Operators, which runs the state’s electrical grid. The state has additional energy capacity at the moment “but blackouts, rolling, rotating outages are a possibility,” Mainzer said, calling additional conservation “absolutely essential.”

The CAISO site Tuesday morning showed California could fall more than 5,000 megawatts short of its power supply at peak demand, forecasted for 5:30 p.m.

California’s energy grid runs on a mix of mostly solar and natural gas during the day, along with some imports of power from other states. But solar power begins to fall off during the late afternoon and into the evening, which is the hottest time of day in some parts of the state. And some of the aging natural gas plants California relies on for backup power aren’t as reliable in hot weather.

At CAISO’s request on Monday, four temporary emergency power generators deployed by the Department of Water Resources in Roseville and Yuba City were activated for the first time since they were installed last year, providing up to 120 megawatts, enough electricity for 120,000 homes.

CAISO also has issued a Flex Alert call for voluntary conservation between 4 p.m. to 10 p.m. Tuesday, making seven alerts in as many days.