With spring only days away, PJM Interconnection reported March 18 that its grid performed well during a winter season that brought extreme cold temperatures and high electricity demand.
PJM, which oversees the power grid for 13 mid-Atlantic and Midwestern states and the District of Columbia, said that during the 2018-2019 winter season, generator performance continued to improve, and wind generation reached an all-time peak of 7,808 MW on Jan. 9. While a major natural gas pipeline ruptured in Ohio, that event did not have a significant impact on generation.
PJM President and CEO Andrew Ott said the winter results show the grid is "strong, diverse and reliable."
"We will continue to analyze the dependability of the fuel-supply system to make sure we're reliable under extreme conditions, and craft appropriate market reforms to offer proper incentives to generators providing critical reserves," Ott said in a statement.
Jan. 28-31 brought a brief snap of well below 0 degrees Fahrenheit, weather that prompted some grid operators to call off planned maintenance work and tell generators to be ready for any demand changes.
During this cold spell, forced outages were slightly higher than normal winter operations, typical for extreme cold periods. Overall, though, generator performance continued to show "marked improvement" over the "polar vortex" winter of 2013-2014.
During that winter, PJM saw forced generation outages of up to 22%. During the winter of 2017-2018, an extended cold snap led to forced outages of 12%. On Jan. 30 and Jan. 31, 2019, outages were down to 8.6% and 10.6%, respectively.
According to a Cold Weather Operations Summary of the 2019 event, output from natural gas-fired plants increased during this winter's cold spell, while output from coal fell. During the winter peak load Jan. 31, gas made up 32% of the fuel mix and coal made up 34%. About 3,300 MW of coal units retired between Jan. 1, 2018, and Feb.1, 2019, the grid operator said.
Gas supply outages were 2,930 MW at peak demand, well below the 5,913 MW in supply-related outages during the 2018 cold weather event. Fuel-supply related outages fell by more than 50%, PJM said. Several factors, including generators "firming up" gas supply contracts, pipeline expansion projects, improved gas/electric coordination and the relatively short duration of the cold weather, helped improve that figure.
Most natural gas-fired generation outages were due to internal plant issues, such as mechanical failures, rather than fuel supply issues.
This winter also showed that pricing in PJM's reserve market during stressed conditions showed that valuable energy reserves, while adequate during these periods, were not appropriately compensated in the market, the grid operator said.
On Jan. 31, synchronized reserve market prices in PJM were at or near zero for 19 of 24 hours, which PJM said suggests that those reserves have little or no value. Synchronized reserves can provide power to the grid within 10 minutes or quickly remove electricity demand. PJM plans to file a proposal with the U.S. Federal Energy Regulatory Commission in the near future to improve the way reserve prices are formulated.