A massive winter storm on Wednesday that blustered over more than 30 U.S. states, from New Mexico to Maine, shut off the lights for millions around the country. Regional grid operator the Electric Reliability Council of Texas (ERCOT) instituted an energy emergency and instructed utilities to begin rotating blackouts throughout Texas to compensate for 7,000 MW of power plants that were shut down as a result of the cold snap.

ERCOT said more than 50 generating units had tripped, and “additional units are continuing to trip offline due to the extreme cold temperatures.” The transmission body said it was not known how long the need for rotating outages—lasting 15 minutes to an hour—would last, and it appealed for energy conservation.

Doyle Beneby, president and CEO of CPS Energy, told reporters that Texas was not set up to deal with widespread low temperatures. “There’s not enough generation to take care of everyone on the state grid,” he said.
Hourly wholesale power prices in Texas soared to $3,000/MWh from the typical $50/MWh. ERCOT forecast that peak demand would top 55,000 MW on Wednesday and 57,000 MW on Thursday before dipping to 47,000 MW on Friday. ERCOT’s peak summer load in 2010 was 65,715 MW.
In Illinois, roughly 58,000 ComEd customers were without electricity Wednesday, including 43,000 customers in Chicago, which is being pummeled by the third-largest blizzard in its history. The blizzard had knocked out electricity service to roughly 180,000 customers in the Chicago metropolitan area, but service was restored to 119,000 customers, ComEd spokeswoman Tabrina Davis said Wednesday.

Even Phoenix, Ariz., was hard-hit. About 65,000 customers were without electricity in the city’s metropolitan area Wednesday morning because coal-fired units in Springerville and Page each had a unit go offline, likely because of the cold. Salt River Project spokesperson Patty Garcia-Likens told local television stations that this forced the utility to institute blackouts. Power had been restored by 8 a.m., however, she said.

Sources: POWERnews, ERCOT, ComEd, SRP