HOUSTON — As freezing temperatures enveloped Texas late Thursday and into Friday morning, demand for electricity shattered the grid operator's peak expectations for the maximum amount of power people would use to stay warm this winter.
Luckily, the state's grid held, but the resiliency test isn't over: High demand is forecast to continue into Saturday while power supplied from wind, which has been offering a significant boost during the blustery Arctic blast, will likely drop off.
Electricity demand hovered around 74,000 megawatts Friday morning and was projected to decrease as the day warms. That far surpassed the previous winter record of 69,871 megawatts during the 2021 storm. But that record demand doesn't account for how much power Texans might have used then because blackouts hit much of the state.
Officials Thursday had predicted Friday morning demand would be closer to 70,000 megawatts. The difference between reality and expectation was even starker overnight, with electricity use at some points more than 10,000 megawatts higher than officials predicted.
"That's been the big surprise so far," said Daniel Cohan, an atmospheric scientist at Rice University. "The demand forecast wildly underestimated how much electricity Texans used last night."
With such a miss in projections, experts were focusing their concern on how the grid would hold up Friday night. Officials with the Electric Reliability Council of Texas, which manages the grid that powers most of the state, still expected enough power to be generated to keep the lights on and electric heaters running. But if forecasts are off again, or if problems occur with any natural gas suppliers or plants, it could bring a triggering call from grid operators for residents to conserve power.
Temperatures dropped to single digits across the state Thursday, with lows hitting 1 degree in parts of the Panhandle Thursday night, according to the National Weather Service. The winter weather brought wind gusts up to 40 mph in parts of North Texas. Some parts of the state saw light flurries, but the precipitation did not stick to the ground.
At least one person, who was found unresponsive outside a Fort Worth McDonald's, died, according to news reports.
The grid operator's performance so far highlighted the uncertainty in forecasting power demand in such rare, freezing conditions, Cohan said. No one knows how high demand for power would have gone during the winter storm in February 2021, when grid operators called for power cuts to many because demand was dangerously on pace to far outstrip supply.
ERCOT's seasonal assessment for this winter predicted a peak demand of 67,398 megawatts; the 2021 storm required more than that. The state's population has meanwhile grown, topping 30 million this year.
Looking back in time to forecast for volatile weather ahead does not work, said Ed Hirs, an energy economist at the University of Houston.
"They have done a poor job here of estimating peak demand," Hirs said. "So why? Why are they short? This is an indication of, number one, rewarding incompetency."
The Texas electric grid is designed primarily to be reliable during the summer, said Michael Webber, professor of energy resources at the University of Texas at Austin. Power plants aren't housed in buildings to keep in heat but rather left exposed so heat can escape in the summer. This, of course, becomes a problem in the winter.
Power producers after the 2021 storm took steps to better protect against extreme cold. Natural gas producers didn't face the same pressure, Webber said. If gas production freezes up, that can create a problem, as happened in 2021. Gas power is normally dominant in Texas winter.
"We built the whole system around the notion that we're all going to crank our air conditioners at 5 p.m. in August, and now we need to do that and operate the system when we're all cranking our heaters at 10 p.m. in December,” Webber said. “It’s notable and surprising and relevant that peak demand in winter might happen today. Holy cow. We didn’t design our system like that."
ERCOT and the Public Utility Council, which regulates the grid operator, made improvements after 2021, such as ensuring natural gas-fired plants have additional sources of fuel on site and improving communications among electricity regulators, oil and gas regulators and the Texas Division of Emergency Management.
But soaring electricity use further showed that ERCOT has done little to encourage reducing demand at the individual level, helping people improve energy efficiency of their homes, for example, or paying them to turn the thermostat down, said Luke Metzger, executive director of Environment Texas.
Reducing demand would also help reduce the pollution that is fueling climate change that drives extreme weather, Metzger noted.
"Clean energy again clearly has to be the answer because we need to avoid the climate change that's causing the extreme weather that's fueling the grid instability," Metzger said.
Even with the grid running smoothly so far, some Texans still saw outages. In the greater Houston area, around 16,000 CenterPoint Energy customers were without power at 9 a.m. because of the strong winds, and 189,000 had lost power but had it restored within the past 24 hours.
Thousands of households in Bandera and Medina counties, near San Antonio, were also experiencing power outages Friday morning because of surging demand and equipment failures. An official with Bandera Electric Cooperative, a local utility company, said they were having to shift the load around, causing isolated rolling outages.
MedStar EMS, the regional emergency medical service for over a dozen North Texas cities including Fort Worth, responded to 27 calls for cold-related illnesses between 9 a.m. on Thursday and 6 a.m. Friday. Twenty three patients were transported to area hospitals, two in serious condition. One of those patients was found unresponsive and later died, according to a report from KDFW-TV.
Texans can expect the cold temperatures to continue through Friday and into Saturday morning, remaining below freezing for most of the state until Christmas Day.
Pooja Salhotra and Lucy Tompkins contributed reporting.
Disclosure: CenterPoint Energy, Rice University, University of Texas at Austin and University of Houston have been financial supporters of The Texas Tribune, a nonprofit, nonpartisan news organization that is funded in part by donations from members, foundations and corporate sponsors. Financial supporters play no role in the Tribune’s journalism. Find a complete list of them here.
This article originally appeared in The Texas Tribune at https://www.texastribune.org/2022/12/23/ercot-power-winter-weather/. The Texas Tribune is a member-supported, nonpartisan newsroom informing and engaging Texans on state politics and policy. Learn more at texastribune.org.
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