Mass. drivers will save money charging EVs at night — but when and how much?

Charging electric vehicles in Massachusetts could get less expensive under a pair of utility proposals now under consideration, but advocates are arguing for tweaks they say would make the transition faster and more fair.

A 2022 state climate law requires the state’s two major electric companies, Eversource and National Grid, to submit proposals for so-called time-of-use rates offering lower prices to electric vehicle owners who charge their cars during times of lower demand hours. The utilities did so in August 2023, proposing off-peak rates they say could save users hundreds of dollars a year compared to basic service rates.

“We are very supportive of time-of-use rates, broadly speaking,” said Oliver Tully, director of utility innovation and reform at climate nonprofit the Acadia Center. “We want to make sure these initial plans are as strong as possible.”