California facing chance of blackouts amid brutal heat wave

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 pm.

The danger of wildfires was extreme as scorching heat and low humidity turned brush to tinder. Four deaths were reported over the Labor Day weekend as some 4,400 firefighters battled 14 large fires around the state, with 45 new blazes on Sunday alone, said Anale Burlew, a deputy chief with the California Department of Forestry and Fire Protection.

In Southern California, two people were killed and one injured by the Fairview Fire, which started Monday near the city of Hemet, the Riverside County Fire Department said. Roughly 50 miles (80 kilometers) southeast of Los Angeles, the fire had quickly spread to at least 2,400 acres (971 hectares), prompting evacuations, and was only 5% contained. Multiple residential structures burned.

The dead people were not immediately identified. Authorities said both were found in the same area but it was not known if they were from the same household. They were apparently trying to flee when they were overcome.

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. Consumers were urged to keep air conditioners at 78 degrees (25.5 degrees C) or higher during the period and avoiding using major appliances such as ovens and dishwashers.

The efforts have worked to keep the lights on "but we have now entered the most intense phase of this heat wave" that could last into the week, and two to three times the level of conservation will be needed from people and businesses, Mainzer said.

CAISO also issued a Stage 2 Energy Emergency Alert from 6:30 p.m. to 8 p.m. Monday. The second of three emergency alert stages means taking emergency energy-saving measures "such as tapping backup generators, buying more power from other states and using so-called demand response programs," according to a CAISO website. Stage 3 would be rolling blackouts.

Several hundred thousand Californians lost power in rolling blackouts in August 2020 amid hot weather, but the state avoided a similar scenario last summer. Gov. Gavin Newsom signed legislation on Friday that could allow the state's last remaining nuclear plant to stay open beyond its planned 2025 closure, to ensure more power.

The National Weather Service predicted highs between 100 and 115 degrees (37.7 C and 46.1 C) across inland California, with 80s to 90s (above 26.6 C and below 37.2 C) closer to the coast. Nighttime won't bring much relief, with many places seeing lows in the 80s or even 90s (above 26.6 C and below 37.2 C).

Ironically, unsettled weather also brought the chance of thunderstorms over Southern California and into the Sierra Nevada, with a few isolated areas of rain but nothing widespread. The storms also could produce lightning, forecasters said, which can spark wildfires.

South of the Oregon state line, the Mill Fire was 55% contained Tuesday morning after killing two people, injuring others and destroying at least 88 homes and other buildings since it erupted last week, CalFire said. The bodies of the two women, 66 and 73, were found in the city of Weed on Friday, the Siskyou County Sheriff's Office announced Monday. Details weren't immediately released.

A few miles away, the Mountain Fire grew to nearly 18 square miles (29 square kilometers) square miles and only 20% contained, with winds threatening to renew its eastward spread in steep terrain, fire officials said.

Scientists say climate change has made the West warmer and drier over the last three decades and will continue to make weather more extreme and wildfires more frequent and destructive.