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The vast majority of the roughly 860,000 customers in CPS Energy’s service area woke up to working lights and appliances Thursday, with the utility saying it has restored power overnight to all but 9,000 customers.

CPS Energy made significant progress late Wednesday and early Thursday as Texas power grid operators reported more power plants coming back online. At 7 p.m. Wednesday, the Electric Reliability Council of Texas (ERCOT) reported that it had had enough supply return to the grid to restore 8,000 megawatts of demand – enough to power 1.6 million households in freezing conditions.

Still, as of 8:30 a.m. Thursday, ERCOT reported 40,000 megawatts of power plant, wind farm, and solar array capacity that has been forced off the system because of frigid weather. Of that, 23,500 megawatts was made up of natural gas, coal, and nuclear plants, and nearly 16,500 megawatts was wind and solar generation.

ERCOT officials said as of Thursday morning, they had stopped requiring transmission companies such as CPS Energy to cut customers’ power, although a return to planned outages “may be needed over the next couple of days to keep the grid stable.”

Unprecedented single-digit temperatures across Texas has crippled the energy industry this week, with many power plants left without the kind of cold-hardy materials, insulation, and prep work needed to operate in such conditions. ERCOT officials and power generators have said they prepared for below-freezing temperatures but were blindsided by such a long, sustained deep freeze with temperatures in the single digits.

At a high point Tuesday, more than 300,000 CPS Energy customers were without power.

CPS Energy President and CEO Paula Gold-Williams told San Antonio City Council members Wednesday that Texas won’t see sustained power return until warmer weather arrives. Snow returned to the area Thursday morning, with forecasts calling for high temperatures in the mid-30s.

“Until the wet part of the storm totally leaves, we won’t see relief from the outage management process to re-stabilize the entire grid,” Gold-Williams said.

More people could be intentionally plunged back into darkness later this week, with ERCOT still reporting slim margins of extra generation capacity that serves as a buffer between supply and demand. The grid operator’s forecasts show demand for power outstripping supply by Thursday afternoon.

CPS Energy is responsible for roughly 7 percent of the demand on the Texas grid and must cut its customers’ power by roughly that rate to meet ERCOT’s requirements when supplies are tight.

On Wednesday, CPS Energy officials also warned that much of their equipment sustained damage as they worked to stabilize the grid. Some customers might be left without power until Monday.

Gold-Williams said the utility has seen “fuses blown trying to keep the power stabilized.” Fuses are safety devices meant to protect a circuit from too a large a current flowing through it, which can damage the circuit and cause fires.

“Which means that when we come out of this outage management process, we’re going to have to re-send our employees out into the field to replace fuses and fix equipment,” Gold-Williams said.

“Even on Saturday, some people will come automatically up and stay up, but some people will have sustained outages,” she said.

CPS Energy is a financial supporter of the San Antonio Report. For a full list of business members, click here.

Brendan Gibbons is a former senior reporter at the San Antonio Report. He is an environmental journalist for Oil & Gas Watch.