- A new report by the North American Electric Reliability Corporation shows the nation's power grid generally responded well to extreme temperatures caused by the polar vortex in January.
- Load sheds were avoided by demand-side reductions and voltage reductions, even as some areas faced low temperatures 35 degrees below normal. Because of the demand spikes, significant amounts of gas-fired generation were also curtailed because of commodity shortages.
- Only one balancing authority was required to shed load -- less than 300 MW, representing less than 0.1% of the total load for the Eastern and ERCOT Interconnections. The report found that many outages were the result of temperatures that fell below a plant’s design basis.
Last winter's polar vortex stressed the nation's power grid as a mass of cold air enveloped the country. The average daily temperature in the U.S. on Jan. 6 was just under 18 degrees, the first time that had happened since 1997. On Jan. 7 there were at least 49 record low temperatures set across North America.
And yet, a new report by NERC finds the system generally held up well. "System Operators had many challenging decisions to make as a result of lost capacity from both weather conditions exceeding the design basis of generating units, and from the lack of availability of natural gas," the report said. "They successfully maintained reliability through extensive training and preparation."
The report does make several recommendations, including reviewing natural gas supply and transportation issues, working closer with gas suppliers, markets, and regulators and considering winter preparation site reviews.
The report also suggested considering "the temperature design basis for generation plants to determine if improvements are needed for the plants to withstand lower winter temperatures without compromising their ability to withstand summer temperatures."
PJM Interconnection has already proposed new rules aimed at ensuring a more diverse bank of resources are available during peak periods.