Vermont’s natural gas utility is teaming up with two local affordable housing developers to experiment with using geothermal energy to heat a new neighborhood in Hinesburg without fossil fuels.
Champlain Housing Trust and the developer Evernorth expect to break ground on the 44-unit Riggs Meadow development this summer. The buildings will use ground-source heat pumps, which extract warmth from the ground for heating. Vermont Gas Systems says this will be the first neighborhood-scale geothermal project in the state.
Geothermal energy requires a big upfront investment to drill into the ground and build out “loops” of circulating fluid, but after that, the only ongoing costs are for maintenance. The upfront cost has historically kept affordable housing developers from leveraging the technology.
Plus, natural gas has typically been more affordable in Chittenden County, though heating with fossil fuels can leave tenants vulnerable to price volatility. Amy Demtrowitz, chief operating officer for Champlain Housing Trust, said the geothermal proposal provides a more stable alternative.
“The efficiency of the geothermal system allows us to stabilize that energy cost that we’re including in the rent, so we won’t need to be looking at larger rent increases,” Demetrowitz said.
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Under Champlain Housing Trust’s agreement with Vermont Gas Systems, the utility will drill the loops at Riggs Meadows, install them, maintain them and essentially sell heat to the nonprofit like it sells gas at other properties.
Vermont Gas Systems says the geothermal technology works particularly well for new construction and fits well with the skills a gas utility already has in-house.
“There’s a lot of similarity between geothermal and gas,” said Vermont Gas Systems CEO Neale Lunderville. “We literally use the same pipes under the ground. Different things are running through those pipes… but it’s something our teams are very well versed in.”
Vermont’s Public Utility Commission authorized the utility to use special funds set aside in its budget for experimenting with new technologies that reduce emissions to meet state energy and climate goals.
Documents filed with the commission last year estimate using ground source heat pumps in lieu of natural gas at the development will save almost 30 metric tons of carbon dioxide emissions each year.
The same filings estimate that ground-source heat pumps are roughly 30% more efficient than conventional air-source heat pumps, which are less effective in extreme cold.
The Riggs Meadows development will feature 36 one-, two- and three-bedroom apartments for low- and moderate-income renters, along with a child care center and conserved land with public trails.
Green Mountain Habitat for Humanity plans to build several townhomes for purchase through CHT’s shared equity program, most likely in 2027.
The housing project is poised to cost roughly $20 million, funded through a mix of federal and state grants and housing tax credits. NRG co-founder Jan Blomstrann donated the land.
Vermont Gas Systems estimates drilling and installing the geothermal infrastructure for the initial phase of the project will cost roughly $275,000.
