ISO New England is reporting that for the first time in a single year, it has recorded over 100 days in which energy demand actually went down in the middle of the day due to solar use.
In 2024, 106 days were characterized as “duck curve days,” named after a curve in the energy usage graph that loosely resembles waterfowl in profile. These are times in which energy demand dips in the middle of the day.
“Typically, in years past, we would think that the overnights would be when we would see less energy demand, right? Because most folks in New England are sleeping at that time,” said Mary Cate Colapietro, a spokesperson for ISO New England.
Colapietro said these instances are a direct result of increased solar usage.
“Midday energy demand was lower than it was overnight,” she said. “And this is happening because of the adoption of what’s called behind the meter solar, which are these smaller scale systems that often are on folks as rooftops, or sometimes you’ll see them on top of commercial buildings or by parking lots.”
Duck days have been on the rise since ISO New England first started tracking ‘duck days’ about six years ago. In 2022, there were 45, and in 2023, there were 73 duck days. Colapietro said the trend is expected to continue in the coming decade.
Maine Public’s Climate Desk is made possible by Androscoggin bank, with additional support from Evergreen Home Performance, Bigelow Laboratory, & Lee Auto Malls.
This story was originally published by Maine Public. It was shared as part of the New England News Collaborative.
