Eversource Energy, the utility that supplies natural gas to much of Central and Eastern Massachusetts, has proposed cutting customers’ gas bills an average of $20 a month for March and April.
The company, formerly known as NStar and Northeast Utilities, said Monday that it has sought Department of Public Utilities approval to adjust costs downward for its 300,000 gas customers, based on lower-than-expected costs.
Electricity rates would not change for the utility’s 1.3 million power customers in Massachusetts, however.
Michael Durand, a spokesman, said Eversource cannot change its electricity rates, which are locked in place for six months by state law. It frequently seeks adjustments to its natural gas rates, however, which the utility sets partly according to long-term contracts and partly by the volatile futures market, Durand said.
By one measure, natural gas futures prices have recently fallen to a five-month low.
Eversource raised electricity rates 29 percent this winter because of higher costs from generators. At the time, the company cited expected price surges for natural gas, which many power plants in New England burn to generate electricity.
For the average customer who uses gas for home heating, Eversource said bills would drop from $171 per month to $151, nearly a 12 percent cut. The company said “fluctuations in wholesale market prices” had led it to seek permission to cut the rate it charged customers for gas from 74 to around 60 cents per therm. Households with gas hook-ups that use oil or other fuels to heat their homes would not benefit as much.
A spokeswoman for Attorney General Maura Healey, whose office contested the winter electricity rate increases proposed by National Grid and Eversource, welcomed Eversource’s announcement. “This is positive news for ratepayers, especially considering the winter that we are currently having. It is also a further reminder of the work we must all do to keep rates as low as possible for ratepayers in the future,” said Jillian Fennimore.
The move comes on the heels of cuts by National Grid, which serves Boston and Northeastern Massachusetts. Jake Navarro, a spokesman for the company, said it had cut rates by 5 percent in January and 6 percent in February, saving a typical household $20 a month over the rates it would have paid.
“We’re pleased to be passing along this price cut to our customers during what has so far been a very difficult winter for everyone,” Bill Akley, Eversource’s president of gas operations, said in a statement.
Jack Newsham can be reached at jack.newsham @globe.com. Follow him on Twitter @TheNewsHam.