Enrolled heat pump homes pay 9.3 cents less a kilowatt-hour for National Grid delivery starting Nov. 1, 7.8 cents less at Eversource

SOUTH COAST South Coast homes that heat with a heat pump pay less to have their electricity delivered from Sunday, Nov. 1, through April 30, if they are enrolled in the seasonal heat pump rates National Grid and Eversource offer. This winter National Grid's heat pump rate cuts the transmission charge as well as the distribution charge, as Eversource's already did, under a state order issued in June.

Under the summary of rates the Department of Public Utilities approved Oct. 30, a regular National Grid home pays 24.405 cents a kilowatt-hour for delivery starting Nov. 1. A home on the heat pump rate pays 15.117 cents, 9.288 cents less, or about 38%. For every 1,000 kilowatt-hours the house uses in a winter month, that is $92.88 less on the delivery side of the bill.

Eversource's posted delivery rates for eastern Massachusetts, in effect Sept. 1 through Dec. 31, show its heat pump rate cutting 7.828 cents a kilowatt-hour from November through April, or $78.28 for every 1,000 kilowatt-hours. Added together, those posted delivery charges for a New Bedford area home come to 18.635 cents a kilowatt-hour on Eversource's standard residential rate and 10.807 cents on its heat pump rate, lower than National Grid's on both. Each company also bills a $10 monthly customer charge. The company says customers on the rate paid about $430 less last winter, about $72 a month.

What changes on the bill

At National Grid, the heat pump rate lowers two charges. The distribution charge drops from 12.5 cents to 8.199 cents a kilowatt-hour, and the transmission charge drops from 5.464 cents to 0.477 cent. The tariff applies the heat pump charges to the home's kilowatt-hour use in those months, not only to the heat pump, and the cut is the same 9.288 cents for households on National Grid's income-eligible rate before their percentage discount comes off the bill.

Eversource's heat pump rate lowers its winter distribution charge from 9.837 cents to 5.286 cents a kilowatt-hour and its winter transmission charge from 4.673 cents to 1.492 cents, with a slightly lower revenue decoupling charge as well. From May through October, heat pump customers pay the standard residential rate, the company says.

Neither discount touches the price of the electricity itself. Eversource says the rate is on the delivery side of the bill, so homes that buy power through a town electricity program or another supplier qualify too.

National Grid's filing gives an example of a home using 1,652 kilowatt-hours in November, an average 600 kilowatt-hour house plus a 3-ton heat pump. At the rates now in effect, the heat pump rate takes $153.44 off that home's National Grid delivery charges for the month, and at the same use Eversource's posted rates come to $129.32 less.

What is new at National Grid

On June 1 the department ordered National Grid to propose winter transmission charges for its heat pump customers for the 2026 to 2027 heating season, modeled on the ones it approved for Eversource's heat pump rate in 2025. National Grid filed the plan June 15, and the department stamp-approved it July 29.

The 0.477 cent transmission charge covers only November through February, because the company's transmission cost year runs March to February and the discount starts partway through it, the filing says. From March 1 the charge will be recalculated over a full six-month winter, and the company's bill examples used a full-season figure of 1.998 cents. National Grid's June filing says that from March 2027, the heat pump transmission rate combined with a heat pump distribution rate the company proposed in a separate case, D.P.U. 26-84, would save customers about 20% compared with standard rates.

WBUR reported in April that about 140,000 households statewide had enrolled in the three utilities' heat pump rates, according to the companies, and that state officials had predicted an average household would save $540 in the first winter.

Who gets which rate

National Grid delivers electricity in Fall River, Somerset, Swansea, Rehoboth and parts of Dighton and Westport. Eversource delivers it in New Bedford, Dartmouth, Fairhaven, Acushnet, Freetown, Marion, Mattapoisett, Rochester, Wareham and part of Westport, according to the state's Energy Switch lookup by ZIP code.

Homes on the Taunton Municipal Lighting Plant, in Taunton, Berkley, Raynham and part of Dighton, and homes on the Middleborough Gas and Electric Department get their power from those town-owned utilities, so neither company's heat pump rate applies to them. Our story A Taunton light plant home using 600 kilowatt-hours pays about half what Eversource and National Grid customers nearby pay compares those bills.

How to sign up

Both companies require enrollment, and National Grid's tariff opens the rate to residential customers with a device that heats all or part of the home in winter, or supplements another heat source, by moving heat in from outside the way a heat pump does. The company has to confirm the device, and the rate starts with the first bill after enrollment. A customer who joins can return to the standard rate after 12 billing cycles but then has to wait 12 more before switching back. The tariff points customers to enrollment rules on National Grid's website, and Mass Save's heat pump rate page links to National Grid's heat pump rate page at nationalgridus.com.

Eversource says customers who received a Mass Save rebate through their Eversource account for a heat pump installed after Jan. 1, 2019, are enrolled automatically and notified. Others apply online by uploading one document, such as a receipt for the equipment, a contractor's invoice, a Mass Save rebate confirmation or a photo of the outdoor unit showing its model and serial number. Applications can also go by mail to Abode, c/o Eversource Energy, 555 Virginia Road, Concord, MA 01742.

Homes heated with electric resistance heat, such as baseboards, space heaters or furnaces, do not qualify, Eversource says. Customers on its R-2 discount rate can move to an R-2 heat pump rate and keep their discount, and homes with solar panels can join, though the company says their savings may be smaller.

The heat pump rates run alongside the other winter changes that began Nov. 1, including National Grid's higher assistance charge and the new income-based discounts in our story Typical National Grid electric bill rises $9.46 a month in the Fall River area as bigger income discounts begin Nov. 1.

Label: Reported by us, from the town's posted records.