The longest heat wave recorded in parts of New Hampshire is subsiding. And with the heat dissipating, so is the demand on New England’s energy grid.
On July 23, electricity demand on the grid hit its peak for the year at about 24,300 megawatts. That is slightly lower than the peak demand the grid experiences typically during the summer, which has averaged about 25,600 megawatts since 2000. But it was higher than last year’s peak of about 23,500 megawatts.
Mary Cate Colapietro, a spokesperson for ISO New England, which runs the regional grid, said the grid remained reliable throughout the heat wave, though weather is the biggest driver of energy use.
“Being able to look out and see if there’s going to be a longer stretch of those 90 or 90-plus degree temperatures is really important for us to be able to communicate that to the power producers and the transmission operators to ensure that the power is there when it’s needed,” she said.
Hot, humid weather is a particular concern for grid operators, Colapietro said.
“As those dew points grow higher, those air conditioners are going to have to work a lot harder to keep cool,” she said.
The grid operator released an alert about abnormal conditions about the grid this week, which was meant to let power producers know they should be ready to deliver power, Colapietro said.
During June’s heat wave, ISO-New England declared a “Power Caution” alert and used reserve resources to meet the demand for electricity. That caused the real-time cost of electricity to spike, reaching $757 at 6 p.m. on June 18. That spike is unlikely to affect electric customers because of how prices are set, the grid operator said.
Summer electricity demand peaks are expected to increase about 1% each year through 2033. New England’s electric demand has peaked in the summer since the 1990s, when air conditioning became more common and electric heating systems declined. But demand is expected to begin peaking in winter months again as more efficient electric heating systems are adopted.
This story was originally published by New Hampshire Public Radio. It was shared as part of the New England News Collaborative.
