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by Ben Perry
How Is Winter Demand for Electricity Different from Summer Demand?
Winter isn’t coming – it’s here. And with cold temps, winter storms, and decreased sunshine come changes to power demand across the US.
The Yes Energy team creates power demand forecasts globally, and we can see that winter peak loads and summer peak loads differ significantly – we’ll show you how.
Let’s explore what winter peak demand often looks like and how that can vary by region.
Why Is Predicting Winter Peak Electricity Demand Important?
Just as in the summer, predicting peak power demand is important because power prices tend to spike when demand does.
Here are a few important characteristics of winter electricity demand to keep in mind.
Electric Demand Summer Vs. Winter
Trend 1: Double Daily Demand Peaks in the Winter
There are typically two daily peaks in the winter, compared to just one peak in the summer.
Summer demand follows the regular patterns of human behavior and temperature. Overnight, businesses are closed and temperatures are typically in a mild range in which very little heating or cooling load occurs.
As people wake up in the morning and begin using power in their homes, temperatures begin to ramp up. Through the day, temperatures continue to rise as businesses and schools are open and consuming power. The temperature peaks in the late afternoon between 2-4 p.m. and demand peaks an hour or two later as there is typically a delayed impact of temperature on power demand. This is also the time of day in which businesses and schools are still consuming power, but people have begun to commute home and will be using more residential power than during the day.
As temperatures drop into the night, so does power demand associated with residential and commercial uses as businesses close and people go to bed.
In the winter, commercial and residential demand ramps up as people wake up and heating demand is at its highest with the coldest temperatures of the day. After the first peak around 7-10 a.m., demand drops due to lower residential consumption, higher temperatures reducing heating demand, and increased behind-the-meter solar generation dropping net load demand. From 5-9 p.m., heating demand rises as temperatures begin to drop, and residential demand rises as people return from work and school, but commercial demand stays high until businesses close later in the evening.
Part of the summer peak is the combination of commercial, industrial, and residential demand spiking in the evening hours when people commute home from work and school. Businesses are still open, but residential consumption also ramps up as people arrive home.
In contrast to the summer, winter peak demand times occur in the morning instead of the evening since the high demand is caused by cold temperatures that occur overnight and into the morning.
You can see an example of this in the Dominion Zone of the Pennsylvania-New Jersey Maryland Interconnection (PJM).
Source: Yes Energy’s Demand Forecasts
Trend 2: Less Solar Generation
In the summer, while demand can spike during high temperatures, sunny weather usually accompanies these, leading to plenty of solar generation.
The winter months see fewer hours of sunlight each day to generate solar power, and even during daylight hours winter storms can bring clouds.
This can cause big events like Winter Storm Elliot hitting Texas in 2021.
Trend 3: Winter Peak Loads Can Vary by Region
In addition, winter peak electricity loads are higher in places with plenty of electric heat relative to other sources of heat, such as gas or steam.
For example, the Southeast US has a much higher proportion of electric heat than the Northeast. This means that although winter temperatures fall much lower in the Northeast, winter peaks in the Southeast are higher relative to the summer peaks than in the Northeast.
Virginia exemplifies this because even though it’s warmer there than in some parts of the country, historically there are peak loads in the winter in Dominion Zone. (Data center load growth also contributes).
Virginia sees high electricity demand in summer, but because of electric heat, there’s a bigger peak in the winter than in the summer.
Source: Yes Energy Demand Forecasts
Source: Yes Energy’s Demand Forecasts
Another trend that affects winter peak demand is that different parts of the US and the world tend to use different fuels for heating. This is in contrast to summer peaks, when nearly all air-conditioning uses electricity as a power source.
Source: Center for Data Innovation. Map shows the dominant fuel for heating.
Stay Ahead of the Competition with Yes Energy Demand Forecasts
You need to be able to trust your electricity demand forecast. That’s why our team is here to explain the reasons behind our forecast.
Unlike many AI-generated demand forecasts, our forecasts are backed by an expert team of analysts and engineers who review and maintain every model, ensuring the most accurate and reliable forecasting in the industry.
Our solution is an advanced regression model that uses detailed demand and weather observation history and incorporates the latest near-term data to respond to changing weather patterns, extreme weather events, and holidays that might impact energy demand.
You need to be able to make the most informed decisions when participating in energy markets around the world, so our forecasts can serve as another tool in your kit to help you predict electricity demand.
Have a question? Ask our team, or request a demo.
About the author: Ben Perry is the senior product manager of forecasting at Yes Energy. Ben brings 10 years of experience as a power demand forecast analyst to the Yes Energy product team. He's now focused on applying that experience to steering the Yes Energy forecasting product roadmap to best serve the industry through the energy transition.
