New England hits a record low in electricity demand thanks to distributed solar
Energize Weekly, June 8, 2022
It was a typical spring Sunday afternoon – sunny with temperatures in the 50’s and 60’s – but May 1 was also historic as the demand for electricity in New England dropped to a record low 7,580 megawatts (MW).
That is the lowest demand since ISO New England, the region’s grid operator, set up shop in 1997.
Sunday typically has a lower demand than the other days of the week, and the weather accommodated by requiring neither home heating or cooling.
It was, however, the sun that made a big difference as distributed solar generation, such as rooftop solar on homes and businesses, accounted for 4,000 MW of electricity.
“New England’s power system is changing right in front of our eyes,” Vamsi Chadalavada, ISO New England’s chief operating officer, said in a statement. “While these changes haven’t happened overnight, a day like May 1 is a good reminder of the progress New England has made in its transition to the future grid.”
What happened May 1 is part of a trend in which solar connected to the distribution network – so called behind-the-meter solar – is dampening demand during the midday and pushing the peak demand on the grid into the evening.
“The ISO first spotted this particular ‘duck curve’ indicating grid demand was lower in the afternoon than overnight, on April 21, 2018,” the operator said. “Since then, solar power has reduced grid demand enough to produce the same-shaped curve 26 additional times.”
“These trends are expected to accelerate over the coming years as behind-the-meter solar continues to grow in New England,” according to the ISO’s 10-year solar forecast.
At the end of 2021, the ISO New England grid had 4,767 MW of distributed solar capacity led by Massachusetts with 2,593 MW. Connecticut with 809 MW, and Vermont with 434 MW, were second and third for distributed capacity.
While on a megawatt basis, Vermont is third in New England, its 434 MW represents about 43 percent of the state’s peak demand.
“Almost every school in the state of Vermont has solar on it,” Chris Root, COO for Vermont Electric Power Co. in Rutland, Vt., said in a presentation to an industry conference in April. “We don’t have large solar. This isn’t like Arizona, where you go in the desert and put 300 MW… We’re talking about distributed resources – this is the model of distributed resources. They’re on houses. They’re on fields. They’re on businesses.”
In 2020, Vermont generated 100 percent of its electricity from renewable resources – a larger share than any other state, according to the U.S. Energy Information Administration.
An average of 30 MW a year of new distributed solar is forecast for Vermont and in Connecticut solar programs are promoting the development of as much as 51 MW a year through 2031, according to an ISO New England survey.