2019 in Review: Reliability Served by Strong Performance, Flexibility

Wind reached a record high output


Despite some very cold winter days, a weekend peak record and a surprising fall heat wave, PJM delivered reliable operations to its members and the 65 million consumers in its area in 2019.

To start the year, PJM energy resources performed well during a short but intense cold spell from Jan. 28 – 31. Lower prices for natural gas-fired generation drove an increase from that resource, while growing coal-fired generation retirements contributed to that sector’s decrease.

Gas-fired generators demonstrated remarkable improvement in performance from the year prior. For example, during the peak demand of nearly 139,000 MW on Jan. 31, gas-supply outages were 2,930 MW compared to 5,913 MW during the 2018 cold snap. All fuel-supply-related outages also fell by more than 50 percent.

This improvement was partially driven by generators “firming up” their gas-supply contracts by paying more for guaranteed gas delivery, pipeline expansions, better gas-electric coordination, improved generator maintenance, and the relatively short duration of the cold weather. A major break in a natural gas pipeline in Ohio occurred during winter peak operations but did not pose a significant impact to generation. The pipeline operator was able to quickly isolate the damaged segment, and gas supply was not interrupted by the event.

Looking ahead, PJM forecasts a warmer-than-average winter in 2020, with a forecasted peak demand of 134,000 MW and ample reserves. Before the winter of 2019-2020 had officially began, wind generation hit an all-time high of 8,005 MW on Dec. 9. At 9 p.m. that night, wind power amounted to 8 percent of the generation mix.

While the summer, as a whole, featured relatively mild weather, it also included a record weekend demand of more than 150,000 MW on Saturday, July 20 (electricity use on weekends is typically lower than weekdays). The peak use for the summer (and the year) was 152,000 MW on Friday, July 19. That peak is far short of the record demand of more than 165,000 MW in the summer of 2006.

PJM confronted its most difficult days in October, during “shoulder season,” when milder temperatures traditionally allow generators and transmission owners to take assets out of service for maintenance. But as October began, a two-day heat wave sent temperatures into the 90s and resulted in an unusually high peak load of 125,500 MW on Oct. 1, which was 5,500 MW higher than forecasted.

PJM members in generation, transmission and load management operated to keep power flowing, despite the fact that the critical planned maintenance activities had temporarily limited generator capacity. Typically, demand at that time of year is closer to 100,000 MW. As unusually hot weather continued Oct. 2, PJM called for emergency procedures, including a Performance Assessment Interval (PAI) and PJM’s first request for energy supply from demand response resources in more than five years.

A PAI measures how well the generation resources that had previously committed to be available to PJM actually delivered when called upon. The PAI tool, a component of PJM’s Capacity Performance rules, provides incentives and penalties to ensure that energy is ready when it is needed most, particularly during extreme heat or cold. Meanwhile, the economic demand response dispatched across PJM on Oct. 2 netted an estimated 16 MW of maximum load reduction.

Through all conditions, PJM and member companies continued to strive for continuous improvement in operations. Toward that end, PJM completed a four-year project to upgrade the seven applications used for load forecasting data in both operations and markets systems. PJM also completed a major enhancement to tools used to ensure generator stability during real-time operations. Finally, on the heels of the groundbreaking, nationally recognized Fuel Security Study released in 2018, PJM and its stakeholders ensured in 2019 that monitoring of fuel and resource security issues will be periodically reviewed via the Operating Committee. After studying 4.7 million scenarios, fuel security has been found in 2018 and 2019 to pose no immediate threat to system reliability, but regular review of this important issue continues as a PJM operations strategy.