Forecasting consumer demand during the COVID-19 pandemic

Residents and businesses across New England are changing their behavior in response to the COVID-19 pandemic. Schools and some businesses have closed, while other companies are transitioning to having employees work from home. These collective actions have changed the way New Englanders consume electricity, in terms of how much is being consumed and the timing of that consumption.

In this Q&A, Mike Knowland, ISO New England’s manager of forecasting and scheduling, discusses how the pandemic is changing the way his team forecasts consumer demand in the region.

How has the pandemic changed electricity demand in the region?

As residents and businesses have adjusted their behavior, we have seen a decline in system demand ofMike Knowland, manager of forecasting and scheduling approximately 3% to 5%, compared to what we would expect under weather conditions in the region. These percentages may change over time.

Our forecasters are seeing load patterns that resemble those of snow days, when schools are closed and many are home during the day. These patterns include a slower than normal ramp of usage in the morning, and increased energy use in the afternoon.

This chart shows the differences in demand patterns between mid-week March days in 2019 (blue) and 2020 (red).

Has the pandemic changed the way you put together the region’s forecasts?

A forecast for electricity demand is a combination of many factors. Weather is always the biggest driver of consumer demand, and that hasn’t changed during the pandemic. Other factors that drive demand are the day of the week, the season, holidays, or other special events.

ISO New England also uses historical data of electricity usage to develop the region’s forecasts. For example, if we are forecasting demand for a Monday in March, we look at what demand was like on previous Mondays in March with similar weather. We can use historical data because people have routines and are creatures of habit. In this situation, there are no similar routines or predictable habits to draw from. These are unprecedented conditions.

To address this, our forecasters are putting together forecasts based on what we would expect demand to be without the pandemic-related changes to societal behavior. Then they are adjusting for these changes based on what we’ve observed over the past days and weeks.

Our team continually updates forecasts as new information becomes available, and that will continue during this pandemic. Forecasters will be closely monitoring system conditions, and will adjust the forecasts based on what they are seeing.

Why do the forecasts on ISO Express and the ISO to Go app sometimes change during the day?

Forecasters are always evaluating real-time conditions—like weather and consumer demand—to see if they match up to the most recent forecast. If conditions are significantly different than what was expected, we will update our forecasts to reflect this new information. We make these updates to ensure reliable operation of the power system and efficient dispatch of the wholesale electric markets. If we do have to update the forecast, the entire 24-hour form is updated.

Do the changes to consumer demand threaten grid reliability?

These changes in consumer demand, themselves, do not pose a threat to reliability. New England’s power system is built and operated to handle fluctuations in demand on a daily and seasonal basis. Spring is also a typically a season of lower consumer demand, as mild temperatures lessen the need for heating or air conditioning.

Are other regions seeing similar changes to demand?

Everyone we talk to is seeing changes to their demand patterns, though the degree of change may vary from region to region. We’re communicating regularly with our counterparts across North America and the globe to report what we’re seeing and share best practices. We are all in this together.