PJM presented updated estimates and analysis of coronavirus-related
impacts to electricity demand at the April 14 Planning Committee meeting.
During weekdays, peak load – the highest point of electricity demand
during a given day – registered
approximately 8 to 10 percent under (or about 7,500 MW) what would be expected
minus COVID-19 social distancing restrictions, said PJM’s Andrew Gledhill in a presentation
to the Planning Committee.
The impact on total daily energy use has been slightly less, with an
average weekday decrease of about 7 percent, or about 140 GWh.
The most dramatic reductions in weekday energy usage were observed on
March 26 and 27, at over 10 percent (around 9,500 MW per day), in the wake of
acute, state-mandated shutdowns of business activity, travel and more.
During weekends, the negative impact caused by virus-related shutdowns
is “noticeably less” at about 2 to 4 percent Gledhill said, reflecting lighter
load corresponding to traditional reductions in weekend business activity.
In general terms, the COVID-19 virus has smoothed out peaks compared to
traditional hourly load patterns of late winter/early spring. Recent weekend
peaks illustrate softer impacts, reflective of traditionally less intense
weekend peak patterns.
“The load shape has been somewhat flatter than typical over the last
weeks,” he said.
Gledhill said these figures will be variable as more data becomes available and hence should be viewed “as a rough guide.”
Fine-Tuning Models to Isolate COVID-19 Behavior
To isolate the impact of the COVID-19 virus apart from weather, PJM
analyzed recent load patterns adjusted for actual temperature conditions dating
back to early March, when notable impacts began, through March 23, when states
and localities began implementing strict stay-at-home mandates, through April 11.
By inserting actual temperatures retroactively, the models will therefore
predict loads without significant error for weather.
PJM also attempted to account for the impact of behind-the-meter solar –
such as solar-powered homes – that reduce peak demand on sunny days but must
draw from the grid at other times. PJM assumed an average March/April behind-the-meter
solar reduction of around 1,300 MW daily, but the historical range is actually
between 0 MW and 2,400 MW, so the conditions on any given day may provide a
margin of error of about 1 percent, Gledhill said.
For revisions to its load analysis and long-term forecast activity, PJM
is closely monitoring inputs and updates from economic firms, namely Moody
Analytics, as conditions evolve.
Evolving Load and Long-Term Forecasts
PJM will discuss long-term forecasts and evolving load patterns at the May
For that meeting, PJM invited transmission owners and members to share data
and analyses from their experiences reflecting changing peak and energy usage
patterns at the local and regional level. As the economy shifts, new patterns
have emerged including higher residential load, Gledhill said, in addition to
expected decreases in commercial and industrial load.
PJM does not have direct visibility into these changes in electricity
sector consumption but depends on its member utilities and other load serving
entities to describe those changes.
“That kind of information would be useful to PJM and other stakeholders
to try to assess how best to move forward,” Gledhill said.
Original source: PJM