The February 2021 Cold Weather Outages in Texas and the South Central United States

The Texas Winter Storm of 2021, also known as Winter Storm Uri, caused widespread power outages, water shortages, and significant economic damage across Texas due to extreme cold weather and inadequate winterization of the state's energy infrastructure.

246 deaths

Texas has added 36 more deaths to the official death toll from the February snow and ice storm, bringing the total to 246 in what was one of the worst natural disasters in the state’s history.

Grid conditions deteriorated rapidly (p8)

A report attributed one of the reasons for the blackouts to be:

• Grid conditions deteriorated rapidly early in February 15 leading to blackouts. So much power plant capacity was lost relative to the record electricity demand that ERCOT was forced to shed load to avoid a catastrophic failure. From noon on February 14 to noon on February 15, the amount of offline wind capacity increased from 14,600 MW to 18,300 MW (+3,700 MW) (see a note below). Offline natural gas capacity increased from 12,000 MW to 25,000 MW (+13,000 MW). Offline coal capacity increased from 1,500 MW to 4,500 MW (+3,000 MW). Offline nuclear capacity increased from 0 MW to 1,300 MW, and offline solar capacity increased from 500 MW to 1100 MW (+600 MW), for a total loss of 24,600 MW in a single 24-hour period.

Note: For wind and solar electricity generation, nameplate capacity is not a meaningful measure of the amount of power generation expected when the unit is not experiencing an outage, though nameplate capacity provides a meaningful metric for the thermal fleet of power plants (e.g., coal, nuclear, and natural gas-fired generating units). Using backcasted values of the available wind and solar radiation, available wind capacity outages actually decreased from 9,070 MW to 5,020 MW (-4,050) over the same time period and solar outages increased less, from 108 MW to 545 MW (+437 MW).

FERC final report

FERC final report provides more details:

• 81 percent of freeze-related generating unit outages occurred at temperatures above the units’ stated ambient design temperature.
• 87 percent of unplanned generation outages due to fuel issues were related to natural gas, predominantly related to production and processing issues, while 13 percent involved issues with other fuels such as coal or fuel oil.
• Natural gas fuel supply issues were caused by natural gas production declines, with 43.3 percent of natural gas production declines caused by freezing temperatures and weather, and 21.5 percent caused by midstream, wellhead or gathering facility power losses, which could be attributed either to rolling blackouts or weather-related outages such as downed power lines.

The Final Report includes 28 formal recommendations that seek to prevent a recurrence of the failures experienced during the February 2021 cold weather event. These recommendations include important revisions to the NERC Reliability Standards surrounding generator winterization and gas-electric coordination.

Additional recommendations are included regarding topics such as cold weather impacts on mechanical and electrical components, utilization of weather forecasts to better predict electric demand, and increasing the ability to rotate rolling blackouts, amongst other recommendations. The report also encourages additional study of the ERCOT system’s reliability issues, guidance on identification of natural gas infrastructure for protection from rolling blackouts, and additional ways to address natural gas fuel supply shortfalls during extreme cold weather events.