California power use to hit record, raising chance of blackouts

The punishing heat wave that has been smothering California for days is set to peak Tuesday, driving power use on the state’s grid to an all-time high and raising the specter of blackouts.

The most populous U.S. state avoided rolling outages from the blistering temperatures Monday, though higher readings Tuesday will further test the network with electrical demand set to climb with schools and businesses reopening after the Labor Day holiday. The National Weather Service forecasts that Sacramento’s airport will hit 115 degrees Fahrenheit – a degree hotter than Monday, which was a record for that date.

“We’re looking at a lot of records today,” said Bob Oravec, a senior branch forecaster at the U.S. Weather Prediction Center. “They are having a lot of issues with power out there, and this isn’t going to help.”

California’s grid operator said the forecast for power usage is “very high” for the next two days, with Tuesday’s peak demand at just over 51 gigawatts at 5:30 p.m. local time. That would set a record, breaking the previous one from 2006, according to the California Independent System Operator, known as Caiso. A gigawatt is enough to power about 750,000 Californian homes.

The historic demands for power increases the likelihood of rotating blackouts unless Californians can reduce energy use even more than they have so far.

“This is an extraordinary heat event we are experiencing, and the efforts by consumers to lean in and reduce their energy use after 4 p.m. are absolutely essential,” Caiso CEO Elliot Mainzer said in a Monday statement.

The prospect of outages underscores how grids have become vulnerable in the face of extreme weather as they transition from fossil fuels to renewable energy. California has aggressively closed natural-gas power plants in recent years, leaving the state increasingly dependent on solar farms that go dark late in the day just as electricity demand peaks. At the same time, the state is enduring the Southwest’s worst drought in 1,200 years, sapping hydropower production.

Much of California is under an excessive heat warning through Friday. The heat wave, which began in the last week of August, is remarkable for both its ferocity and duration, officials said. In addition to daytime heat, overnight lows are also setting records for warmth, which adds to demand.

Last week California Gov. Gavin Newsom issued an emergency proclamation to free up extra power supplies. Some of those were deployed Monday evening, including temporary gas-fired power plants operated by the California Department of Water Resources.

A break from the heat will come across Southern California later this week, thanks to Tropical Storm Kay in the Pacific Ocean, Oravec said. Kay is forecast to edge up the coastline of Mexico’s Baja California peninsula. As it moves north, the storm will pump moisture and clouds into Southern California and Arizona, taking an edge off the heat.