A preliminary report into the February 2021 power outages in Texas and the US Midwest caused by extreme cold weather has identified the causes of the outages and outlined a series of recommendations to better prepare for the coming winter.
The report identified three primary causes of the outages, derates, or failures to start: freezing of generator components, fuel availability, and mechanical/electrical issues. Freezing equipment represented the primary cause of unplanned outages, derates, and start-up failures, accounting for 44% of these unplanned events. Mechanical and electrical issues due to the extreme cold, other than frozen equipment, caused another 21% of unplanned outages, derates, and start-up failures.
The recommendations, set out in the report, jointly authored by the Federal Energy Regulatory Commission (FERC) and the North American Electric Reliability Corporation (NERC) focus on enhanced protection against cold weather for critical generation as well as the natural gas assets supplying gas-fired generation so that this infrastructure remains operational even in extreme cold weather.
The standards approved in August require generators to have a winterization plan and to share certain information with the balancing authority. The reliability standards that will follow from the joint inquiry (if approved) will require specific winterization preparation, including:
- Require generators to identify and protect “cold weather critical components”.
- Build new or retrofit existing units to operate in extreme weather temperatures.
- Account for wind and precipitation in winterization plans.
- Implement corrective action plans for generators that experience freeze-related outages.
- Ensure the system operator is aware of the generating fleet’s operating limitations to allow for mitigation plans.
- Before the upcoming winter, generator owners and operators should review, and communicate reliability risks of, their natural gas fuel contracts to the balancing authority.
The FERC/NERC report recommends some of these standards be implemented before the upcoming winter, but most are expected to be implemented before Winter 2022-2023 and Winter 2023-2024.
Five areas were also identified for further study including black start unit reliability, the need for additional transmission connections to ERCOT, measures to address natural gas supply shortages, the effect of low-frequency events on generators, and guidelines for identifying critical natural gas infrastructure loads.