How the Eversource geothermal network Framingham expansion works
The Eversource geothermal network Framingham expansion would add 44 buildings to a shared underground heating and cooling loop that already serves 126 customers. The loop carries water through buried pipes between connected buildings and a series of wells drilled deep into the ground, moving heat into the earth in summer and pulling it back out in winter, instead of each building burning natural gas on its own. The Eversource geothermal pilot broke ground in 2023 and began operating the following year. Eversource is the utility that owns and runs the loop, and HEET, short for Home Energy Efficiency Team, is the nonprofit partner that helped design and build it alongside the city of Framingham.
Why the finalized grant is 8.6 million dollars, not 7.8 million
The Department of Energy first selected this project in December 2024 with a grant announced at 7.8 million dollars, a figure that still appears in some coverage from that period. HEET own December 2025 announcement describes the 8.6 million dollars as funding for the continuation of an initial design phase award, language that shows the earlier figure covered only a first design stage and the later figure is the finalized amount for building it. The MetroWest Daily News independently reported the same 8.6 million dollar figure 7 months later, in July 2026, describing it as the federal funding Eversource and HEET received the previous December.
What is already connected, and what 44 more buildings would add
The existing loop already serves 126 customers, made up of 16 residential homes, 2 commercial buildings and 108 Framingham Housing Authority customers who were connected when the first phase opened. Those housing authority customers are not new. The 44 buildings this expansion would add are named individually in Eversource own filing, homes on Flagg Drive, Robertson Road, Normandy Road and Dennison Avenue, plus the Framingham Public Schools welcome center. The expansion would add just over half a mile of new pipe, 0.61 miles by Eversource own measure, and double the capacity of the loop by adding 295 tons. This would be the first geothermal network loop in the state to connect with a neighboring loop, according to information Eversource posted on its own website.
These 126 customers were already connected before this expansion. The 44 buildings the expansion would add are separate and not counted here.
Show the numbers
| Framingham Housing Authority customers | 108 |
| Residential homes | 16 |
| Commercial buildings | 2 |
What Eversource still needs to pay for, and how
The federal grant covers only part of the cost. Eversource states in its filing that the project will need an additional 7 million to 9.7 million dollars beyond the 8.6 million dollar grant. Eversource proposes recovering that gap through its existing Geothermal Energy Provision tariff, the same charge it already uses to recover pilot costs, and is asking state regulators to let new participants pay the same rates as existing pilot customers. Eversource filed its request with the Massachusetts Department of Public Utilities in May 2026. Public comment closed July 17, 2026, and Eversource is targeting approval by September 30, 2026, so design and construction work can begin later this year.
Adding the low end of Eversource own estimate to the grant totals about 15.6 million dollars, and the high end about 18.3 million dollars, a total this article calculated by adding Eversource own 2 figures together, not a number the source states directly.
Show the numbers
| Federal grant | 8.6 |
| Additional needed low estimate | 7 |
| Additional needed high estimate | 9.7 |
Nikki Bruno, an Eversource vice president of thermal solutions and operational services, says connecting loops together lets the utility explore gains in reliability, efficiency and affordability. Zeyneb Magavi, HEET executive director, describes what the utility and the nonprofit hope the bigger loop proves.
This award is an opportunity and a responsibility to clearly demonstrate and quantify the growth potential of geothermal network technology.
Zeyneb Magavi, HEET executive director. Source 2.