PJM: Summer Hottest in Last Several Years

The PJM footprint in 2016 summer in the city – and the suburb and rural areas – was hot – the hottest in the last four years.

Both the number of days with temperatures above 90 degrees and the number of cooling degree days were the highest of recent years, according to the report at the Sept. 13 Operating Committee meeting.

Washington, D.C., had more than 50 days with the temperature above 90 degrees. Previously, the number of above-90 degrees  were  under  40 ;  fewer than 20 days  in 2014. Cleveland, which had fewer than five days with the temperature over 90 in the each of the summers of 2013, 2014 and 2015, had 25 in 2016.days-above-90_inside-lines-2

Cooling degree days reflect not only hottest days of the summer, but also persistence of the heat – the number of degrees that a day’s average temp is above 65 degrees. More cooling degree days (CDD) also mean higher overall system demand.

Washington, D.C., and East Kentucky Power Cooperative had the highest total cooling degree days in this summer, with more than 1,400 degrees cumulatively over those days (see chart below). Chicago, with just over 600 CDD totals in each of the three previous summers, had 900 degrees. Cleveland reached 1,000 CDD total in 2016; in 2014, it was barely 500.total-cdd-days_inside-lines

The July 25 RTO-wide peak was 150,826 MW at 4 p.m. and the hot weather alert issued several days before continued through July 27. The Aug. 11 peak was higher at 151,293 MW. PJM had no major operational issues on either day.

Comparing the 2013 and 2016 peak days, PJM found, that although temperatures and humidity on the two peak days were close, the 2013 summer peak load of 157,509 MW was higher. Possible contributors include the rise in behind-the-meter solar and distributed energy resources, better efficiency in light bulbs, television and air conditioners and overall conservation efforts.

Mike Bryson, vice president – Operations, said that PJM will analyse peak days to see how resources would have performed if there have been any capacity performance events.

Capacity Performance

PJM provided updates on the implementation of the unit specific parameter process and different scenarios for performance assessment hour. The performance assessment hour scenarios provided three regulation examples and two reserve examples. The variations in the examples reflect the adjustments to the values that the resources submit.

PJM/NYISO Wheel Termination

PJM gave a status update on the development of new operating protocols for the PJM/NYISO interface. PJM is working with its stakeholder process and NYISO to develop a solution with minimal impact on the loads for both grid operators and which preserves competitive market behaviors, while still serving the public interest and providing consumer benefits. The new approach must be in place for use on May 1, 2017.

Other Committee Business