California’s heat wave caused rolling blackouts for millions

Rolling blackouts hit California August 14 as temperatures soared into the triple digits. | Photo by Yichuan Cao/NurPhoto via Getty Images

Up to 4 million people were hit by “load interruptions” after power reserves fell below a critical threshold.

Soaring temperatures in California spurred an overwhelming surge in electricity use that the state’s grid operator had to cut off power to up to four million people Friday evening.

California Independent System Operator, the body that runs the electric grid for most of the state, initially asked customers to reduce electricity use between 3 p.m. and 10 p.m. by doing things like turning off lights and raising their thermostats to 78 degrees or higher.

But after power reserves fell below a critical threshold, the grid operator then shifted to a “Stage 3” emergency, and triggered “load interruptions” across the state starting around 6:30 pm.

The blackouts underscore how vulnerable the state’s electric grids are to being overwhelmed precisely when people lean on them most for safety and comfort in extreme weather.

Most of the West Coast was under heat alerts on Friday, the first day of an extraordinary heat wave that is expected to continue through the middle of next week and push parts of California into the triple digits.

The states’s utilities began to cut off customers, at least some of the time without advance notice, for brief outages. The state’s biggest utility, PG&E said that the outages occurred for 60 to 90 minutes on a rotating basis in its Northern and Central California territory, according to Bloomberg News.

The blackouts were the largest in the state since “public safety power shutoffs” in the state last fall, when dry, windy weather conditions prompted PG&E to cut off electricity to hundreds of thousands of people for several days at a time. Vox’s David Roberts described the poorly-organized blackouts, which put vulnerable populations at risk and caused chaos for vital services like hospitals and law enforcement, as “absolutely bonkers.”

The weather isn’t getting better for a while

Meteorologists say California — and much of the rest of the country — is in for a rough time with the heatwave that kicked off on Friday.

“A very intense and prolonged heatwave now appears likely for a large portion of California over the next 7-10 days, and this event will likely have wide-ranging impacts from human health, wildfire, and electricity demand perspectives,” wrote Daniel Swain, a climate scientists at the the University of California, Los Angeles on Friday. “I suspect this event will probably end up being one of the most significant widespread California extreme heat events in the past decade, if not longer.”

Parts of Arizona, California and Nevada are expected to reach highs of 110 to 125 degrees during a heat wave expected to last through Wednesday of next week.

“The longevity of the heat is more concerning than the record-breaking temperatures,” National Weather Service meteorologist Trevor Boucher told NBC News.

In 2001, California experienced a series of rolling blackouts, in part because of electricity shortages — but also in part because of “unscrupulous energy traders from companies like Enron ‘gaming’ a badly-flawed grid system and deliberately withholding electricity from California to extort higher prices,” according to the Sacramento Bee.

Grid operators say they’re prepared for future outages, but the likelihood of them over the weekend is smaller because demand shrinks outside of the workday.