With demand projections and available capacity changing by the minute as a winter storm rolled into Texas, ERCOT and state officials spent last week assuaging Texans that the grid will remain standing this week.

Speaking to residents who remember well the devastating February 2021 winter storm that killed hundreds and caused billions in damages when the ERCOT system failed, Texas Gov. Greg Abbott said during a press conference Friday, “I know a lot of people are concerned, ‘Is the power going to stay on?’

“We feel very good about the status of the Texas power grid and ERCOT to be able to effectively and successfully ensure that the power is going to be able to stay on throughout the entirety of this episode,” he added.

The National Weather Service has placed much of the state under a winter weather advisory through Monday, warning of “dangerous” temperatures in the 20s as far south as the Gulf Coast. However, unlike three years ago, little snow or ice is expected.

ERCOT CEO Pablo Vegas said Friday he expects renewable energy to perform as normal, given the lack of precipitation statewide. He said there were no expectations of energy emergencies or conservation calls.

“Things can change and if it does change, we’ll continue to communicate openly over the course of this weekend,” Vegas said.

Sunday evening, things changed. ERCOT issued a conservation appeal for Monday morning due to the freezing temperatures, demand and low reserves. The ISO asked Texans to conserve their electric usage between 6 a.m. and 8 a.m., when solar resources start ramping up and temperatures are forecasted to be below 10 degrees Fahrenheit in North Texas.

ERCOT expects conditions to be similarly tight Tuesday morning. As of 7 p.m. Sunday, the grid operator was projecting a record peak of 86.1 GW, with only 83.8 GW of seasonal available capacity. However, the forecasted curves have changed frequently in the days leading up to the storm’s arrival.

Demand that high is the norm during the summer, having peaked at 85.5 GW in August. ERCOT set its record winter peak of 74.5 GW during the December 2022 winter storm.

The ISO stressed the conservation appeal does not indicate it is experiencing emergency conditions. It said in a press release staff will “remain vigilant and communicate further if conditions change.”

ERCOT also has asked all state and local government agencies to reduce energy use at their facilities until at least 10 a.m. Monday.

The grid operator previously issued a weather watch that went into effect Sunday and expires Wednesday. It said it made the advance notification because of “forecasted significant weather with higher electrical demand and the potential for lower reserves.”

Vegas has said the grid “is as ready and reliable as it has ever been for the winter season.” Legislation passed since the disastrous 2021 winter storm has strengthened the ISO’s weatherization practices — staff have completed nearly 1,800 facility inspections over the past couple of years — and created new ancillary services that can be brought to bear.

SPP Expects Near-record Demand

SPP said it projects to have sufficient capacity to meet anticipated demand this week, despite minimum temperatures in its 14-state Great Plains footprint similar to those observed during the December 2022 storm.

“We have substantial systems and procedures in place and our staff stands ready to mitigate any risks related to maintaining electric reliability,” Senior Vice President of Operations Bruce Rew said in a statement.

With temperatures that could be 30 to 50 degrees below normal, the RTO was expecting load to be as high as 45 GW on Monday and 46 GW on Tuesday. Its all-time winter peak is 47.2 GW, set during Winter Storm Elliott in 2022.

SPP said high pressure building into the Plains behind the cold-weather system may bring a sharp reduction in wind power generation, elevating the risk of outages. The grid operator on Friday issued a conservative operations advisory for its balancing authority area, effective 4 a.m. CT Sunday through 9 p.m. Tuesday.