The finding comes from ERCOT's most recent seasonal analysis of the state grid released Nov. 19. In its winter 2021-22 Seasonal Assessment of Resource Adequacy report, ERCOT also said it is taking an "aggressive approach" to grid management following the widespread and deadly power failures experienced statewide during Winter Storm Uri last February.
ERCOT's SARA reports are based on different scenarios accounting for typical seasonal power usage in addition to potential outages and other emergency situations. The new winter assessment features information covering two scenarios, one for both standard- and moderate-risk grid conditions as well as an "extreme risk" model that was expanded in the wake of this year's disaster.
The demand for power in Texas could peak at 62,001 megawatts this winter, ERCOT said. To cover that projected need, 84,861 MW of generation capacity is set to be available, leaving a reserve gap of 22,860 MW.
Per the grid manager, 1 MW of electricity can power around 200 homes during times of peak power demand.
In its final SARA report released before the winter of 2020-21, ERCOT said electricity demand could reach 57,699 MW while up to 82,513 MW would be available from generators. In fact, ERCOT projected that demand during Winter Storm Uri passed 70,000 MW—nearly 20% above ERCOT's forecast—while tens of thousands of megawatts of generation fell off the grid due to blackouts and operational failures brought on by the deep freeze.
In its modeling for the upcoming winter season, ERCOT found three extreme-risk scenarios that would trigger a level three energy emergency, which could prompt regulated power outages like those seen in February. Those conditions include high demand for power and widespread unplanned outages at electric generation facilities. High-risk projections are based on weather conditions and grid information from past winters rather than upcoming seasonal forecasts.
Oversight and preparations
Texas enters this winter season as state-level power grid oversight and management continue to shift. Electric reliability was one of the main areas of focus of this spring's legislative session, resulting in the passage of a slate of bills aimed at reorganizing leadership, weatherizing power infrastructure and covering the costs of the winter storm. The Public Utility Commission of Texas is also engaged in a broad "redesign" of the state electric market that regulators initiated in response to reliability concerns.
Since Uri, ERCOT has issued multiple appeals for energy conservation due to grid conditions that resulted in a "tight" margin between generation and demand. Whether similar conditions will be experienced this winter remains to be seen, although continental grid regulators with the North American Electrical Reliability Corp. warned last week that an extreme cold event could potentially force Texas into blackouts again.
"Peak demand or generator outages that exceed forecasts—at levels that have been experienced in previous winter events, such as the February 2021 cold weather event—can be expected to cause energy emergencies in [Midcontinent Independent System Operator], [Southwest Power Pool] and ERCOT this winter season," NERC said.
While noting that potential risk, NERC's own seasonal report agreed with ERCOT that the Texas grid appears to have the generation and reserves needed to meet peak demand outside of an extreme weather scenario. That analysis also found a low probability of events comparable to Uri taking place during hours of peak demand.
The regulator called on power generators, whose failures to weatherize their equipment contributed to much of the outages earlier this year, to prepare ahead of winter.
"To be resilient in extreme weather, we are counting on our grid operators to proactively monitor the generation fleet, adjust operating plans and keep the lines of communication open," said Mark Olson, NERC's manager of reliability assessments, in a statement.
A Nov. 16 report from NERC and the U.S. Federal Energy Regulatory Commission highlighted how generators' lax preparations significantly contributed to last winter's power outages. Per FERC's review, winterizing "just four types of power plant components" would have cut ERCOT's blackouts by more than two-thirds.
FERC laid most of the blame for the combination of unplanned outages, failed system starts and decreased generation amid the national February freeze on natural gas producers, which it said accounted for 58% of such issues. Wind generation was responsible for 27% with coal contributing 6% and solar accounting for 2%. Nuclear units and other generation sources accounted for around 8% of the icing and freezing failures.
