Texas just got out of its longest cold spell in six years. Starting Sunday, parts of the state dipped below freezing and stayed there for around three days. Ice caused accidents. Snow brought delight. But one notable outcome was something that did not happen: The lights didn’t go out.
"The last time there was an event similar to this was back in Feb. 2 through 4 of 2011," says Victor Murphy, the climate service program manager for the National Weather Service in Fort Worth. "If you recall during that event, the state electrical grid couldn't handle the demand and the state suffered rolling blackouts."
Temperatures didn’t get as cold this week, but electricity demand was actually much higher. In fact, the demand broke a new winter record, hitting 62,885 megawatts between 7 and 8 o'clock Wednesday morning, says Leslie Sopko, spokesperson for the Electric Reliability Council of Texas, or ERCOT.
So why, under similar weather conditions and with higher electric demand, were there no blackouts? To understand, you've got to remember what caused blackouts the last time.
Part of the problem was that transmission equipment and infrastructure at some power plants actually froze, pushing the plants offline.
"Since then, winter weatherization procedures have been modified," Sopko says. "One of the things that we do is we actually send staff out prior to winter. We send them to spot-visit various power plants to make sure that those procedures have been implemented."
Another problem ERCOT encountered in 2011 was that some gas plants didn't have enough fuel. Sopko says the agency now coordinates better with gas pipeline companies about supply.
She says ERCOT has also improved wind-power forecasting to take into account the impact of ice on wind turbines, all simple things that may guard against future grid failure in times of high demand.
"The demand goes up with the more people and businesses that are in the state," she says.
That doesn't necessarily mean Texas will break any more electricity demand records this winter.
"The overall forecast still for the rest of winter is to have increased chances for above normal temperatures," Murphy says.