PJM released its annual long-term forecast report Dec. 30, to show estimated load growth of 0.3 percent per year for summer and winter peaks over a 10-year planning horizon starting in 2021.
PJM’s independent load forecast was derived using improved modeling techniques to estimate upcoming peak and energy usage trends. In the 2021 Load Forecast Supplement, PJM describes the load forecast process and variables, including residential, commercial and industrial load; weather and non-weather sensitive load; plug-in electric vehicles; behind-the-meter solar; zone-level estimates and more. All forecast values are based on normal (or “50/50”) peak day weather conditions.
Summer Peak Estimates
The forecast estimates summer peak load growth to average 0.3 percent per year for the next decade and 0.2 percent per year over 15 years. Those estimated rates are expected to result in an RTO-wide summer peak of 153,759 MW in 2031 and 154,728 MW in 2036.
PJM’s record summer peak took place in 2006 at 165,563 MW, while this summer’s upcoming peak is forecast at around 149,000 MW.
Winter Peak Estimates
PJM’s record high winter peak measured 143,129 MW in February 2015. PJM estimates a 132,027 MW winter peak for 2021.
In 10 years, modest annual 0.2 percent growth contributes to the projected 2031 winter peak of 135,568 MW, continuing through 2036 to 136,459 MW.
| Year | Summer Peak | Winter Peak | PJM RTO Total Energy |
| 2021 | 149,223 MW | 132,027 MW | 780,068 GWh |
| 2031 | 153,759 MW | 135,568 MW | 806,729 GWh |
| 2036 | 154,728 MW | 136,459 MW | 819,553 GWh |
Improved Long-Term Forecast Model
PJM planners implemented changes to the long-term load and energy forecast model to better align the non-weather-sensitive model with underlying drivers and historical trends. For example, service sector employment was added as a driver to the commercial sector as an indication of economic activity impacting load growth.
The annual forecast also takes into account economic data and other factors that account for effects on load by the ongoing COVID-19 pandemic. The long-term forecast methodology has been adjusted and improved accordingly.
Stakeholders Contribute to Reliable Long-Term Forecast
Close collaboration with stakeholders produces the most accurate forecasts. PJM annually solicits information from its member electric distribution companies (EDCs) for load shifts (either positive or negative) that may be unknown to PJM. For the 2021 long-term forecast, PJM incorporated modeling data input and feedback to help adjust forecasts by zone.
These insights are especially critical in light of load changes wrought by the COVID-19 pandemic. As the economy has contracted in response to government-ordered shutdowns and other pandemic-related load impacts, the long-term load forecast has been adjusted as much as possible, given limited short- and long-term data availability. The Federal Energy Regulatory Commission in June granted a one-time waiver to allow PJM to revise its long-term load forecast in advance of PJM’s July 6 Second Incremental Capacity Auction serving the 2021/2022 Delivery Year.
In comparison to last year’s long-term forecast, the 2021 estimate trims the summer peak forecast by 392 MW (or -0.3 percent). The forecast for the 2024 summer peak (the usual three-year-ahead capacity market auction year) fell by 940 MW (or -0.6 percent). By the summer peak of 2026, the next study year of the Regional Transmission Expansion Plan, the estimated long-term forecast fell by 1.5 percent or about 2,209 MW.
The total amount of energy consumed annually, or net energy, is expected to grow 0.3 percent annually between 2021 and 2036. This is down from the 0.6 percent annual growth estimated in last year’s 15-year forecast for 2020–2035.
Read PJM’s fact sheet to learn more about load forecasting.
Original source: PJM