PJM Working to Refine Load Forecasts to Isolate Pandemic Impact

New Method Seeks to Separate Effect of Weather; Updates to Be Posted Weekly


PJM is working to refine a load forecasting method to identify the impact of human behavioral changes on the demand for electricity as states impose new and ever-restrictive measures to combat the outbreak of the COVID-19 coronavirus.

Chris Pilong, Director – Operations Planning, and Tom Falin, Director – Resource Adequacy Planning, shared PJM’s plan Thursday, March 26, at a Webex meeting of the Markets & Reliability Committee.

Weather and human behavior are the biggest drivers in the short-term load forecast, Pilong said, and recent reductions in electricity demand cannot be instantly attributed to coronavirus measures without factoring in how the weather compares with historical trends.

“We’re trying to tease out the difference between the two of those,” Pilong said. “That is really the challenge at hand right now.”

Going forward, updates on the load analysis methodology will be posted each Monday to the Operating Committee page.

Load Similar to a Snow Day

PJM already has noted an easing of demand as schools and businesses close, and employees set up shop in home offices. (See COVID-19 Lightens Electricity Load, but Reliability Remains Strong.)

The morning peak is arriving later, as many forego their commute; the evening peak is lower, and the load curve is flatter, similar to what the system usually sees on a snow day.

The residential, commercial and industrial sectors all are impacted, Pilong said. The question is, how much? Residential and commercial customers make up 37 percent each of total load, with industrial consumers constituting 26 percent of load.

The reduction in commercial demand is expected to increase residential demand, as workers consume electricity in their own homes.

Industrial load won’t shift to residential, Pilong said. The impact on its demand likely will depend on the actions being taken by individual states.

What makes the analysis complex, Pilong said, is that PJM does not have visibility beyond the transformers to pinpoint where the power is flowing.

“As a residential shift occurs, we won’t see it,” he said. “All we will see is a net change in load.”

Five-Year Historical View

Falin presented a five-year historical view of load for the March 14–24 period, showing actual load regularly dipping below the rolling historical average. March 16 is when the widespread shutdown of businesses began.

However, the comparison did not account for weather. In another chart, Falin showed that half of those days – in particular, those with the largest dip in demand – were warmer than usual. That points to weather as a major factor in the drop in demand.

Analysis is ongoing to get a better picture of what these drops in load can be attributed to.

Long-Term Forecasts Affected, Too

Falin noted that Moody’s Analytics had developed economic forecasts for three scenarios, dependent on the severity of the pandemic.

These will be integrated into PJM’s long-term forecasts, which run through 2035.

Falin said the plan is to have adjusted long-term forecasts based on various scenarios ready to present at the April meeting of the Planning Committee.

In addition, he said, PJM will work to use the most up-to-date load forecasts possible when it resumes its annual capacity auction.