Vermont Gas and Champlain Housing Trust pilot geothermal system at Hinesburg affordable housing site

Vermont Gas Services and Champlain Housing Trust on May 7 briefed the House Energy and Digital Infrastructure committee on a pilot community‑scale geothermal project at the Windy Ridge development in Hinesburg.

The pilot will serve a Rigs Meadow phase that includes a 36‑unit affordable rental development with Evernorth and eight permanently affordable shared‑equity homes built with Green Mountain Habitat for Humanity. Champlain Housing Trust said the property donation included an expectation to incorporate alternative energy, and the organizations plan a utility‑owned, ground‑loop approach in which Vermont Gas owns the inground thermal asset and the housing partners own interior heat‑pump equipment.

The partners said the model reduces the high upfront capital burden for affordable‑housing providers by shifting much of the well‑drilling and loop installation costs to the utility. "We won't bear that high upfront capital cost, but instead we'll pay an access fee to VGS to connect to their geothermal loop system, much like right now we pay VGS for our natural gas connection," Amy Metroitz of Champlain Housing Trust said. Metroitz added that Champlain Housing Trust will also pay an ongoing maintenance fee so a single qualified operator provides emergency and routine service for residents.

Vermont Gas Services described the project as part of the utility's broader effort to offer decarbonization options and new customer products. "We're the state's only natural gas utility. We serve about 56,000 commercial, industrial, and residential customers," Morgan Hood, director of product management at Vermont Gas Services, said, outlining the utility's history with efficiency programs and initial heat‑pump offerings. Hood said VGS began exploring utility geothermal in 2022 and is piloting both independent building loops and networked systems in different contexts.

Committee members pressed the witnesses on cost, payback and regulatory treatment. Witnesses said Champlain Housing Trust generally includes utility costs in rent, so any operational electricity savings would improve tenant affordability. Hood said VGS is pursuing a business model that avoids negative impacts on ratepayers, funding pilots in part from an innovation fund and charging access and maintenance fees to recover property tax and operating costs. On the project payback, Hood said the partners were "saying it's around the seven‑year mark," but cautioned the estimate is simplified and depends on detailed modeling.

The witnesses also described lifespan and durability. Hood said interior geothermal equipment typically lasts 20–30 years with proper maintenance and that inground loop components are expected to have life cycles of 50 years or more; she cited examples of long‑running systems and a Utility Network Geothermal Collaborative convening dozens of utilities to share best practices.

Technical choices discussed included closed‑loop systems filled with glycol (the project's current approach) and siting options such as placing loops under foundations in new construction. The two larger multifamily buildings in Rigs Meadow are expected to use four wells feeding a shared loop; townhome units are expected to have one loop per unit.

Funding history shaped the project's design. The team said the work began with a federal feasibility grant and a national partnership including Gas Technologies Institute, the National Renewable Energy Laboratory and Frontier Energy. Phase two of that grant was awarded in December 2024 but later frozen under a new administration, prompting the team to pivot from a larger networked plan to a lower‑cost configuration with Dandelion Energy to meet Champlain Housing Trust's budget expectations.

On regulatory scope, Hood said Vermont Gas currently has approval to operate within approximately five miles of its service lines and would need regulator conversations to pursue projects outside that footprint. The panel said the pilot is fully funded for the summer construction start and encouraged legislators and local stakeholders to visit the site once drilling begins.

The committee did not take formal action at the briefing; witnesses offered follow‑up technical meetings and said they will return with modeling comparing geothermal operational costs to air‑source heat‑pump alternatives.