Simsbury committee hears experts outline thermal energy networks as a local decarbonization option

Peter Millman of People’s Action for Clean Energy and Debbie New of Vermont Community Thermal Networks told the Simsbury Sustainability Committee on Tuesday that thermal energy networks — shared systems that move heat via pipes and heat pumps between buildings, wastewater and geothermal sources — could reduce greenhouse-gas emissions and lower long-term heating costs in town.

"We burn too much gas and oil to heat our homes," Millman said in the presentation, arguing thermal networks are an important tool to cut fossil-fuel use in residential and municipal buildings. He described existing U.S. projects — including a utility-led pilot in Framingham that operates a roughly one-mile loop serving about 140 customers across 37 buildings — as evidence the approach is operational and replicable.

The presentation covered technical varieties (ground-source loops, wastewater heat recovery, ventilation capture), financing trade-offs and policy supports. Millman cited a study example for a 1,100-home development that showed higher upfront geothermal costs but projected an estimated $100 million in savings over 30 years and a roughly 10-year payback, noting federal incentives such as the Investment Tax Credit and IRA-related funding can substantially lower initial capital needs.

Both presenters said Connecticut’s Thermal Energy Grant and Loan Program — authorized by the legislature — is not yet funded. "It was authorized last year by the legislature … but it has not been funded," Millman said, adding that DEEP would administer the program if funds are allocated. He and New described short-term steps Simsbury could take to be competitive for future grant money: form a community working group, inventory local thermal resources (municipal buildings, ice arenas, grocery stores, wastewater infrastructure), and host stakeholder workshops.

Debbie New said workshops should begin by asking residents how they think about heat and what local priorities are, then move to mapping resources and potential customers. "We start with how people think about heat," she said. "We collect people's experiences of how heat can be very costly, but it's also necessary." The presenters suggested such workshops create the social and political basis needed before spending on feasibility or engineering studies.

Committee members asked about technical constraints and finances. One member asked whether networks can mix municipal and residential customers; both presenters said yes, noting that density matters for financial viability. New said, "Generally, we say that more than a quarter of a mile between buildings is too far," because longer distances increase heat loss and pipe costs. Both presenters cautioned that many operational systems are privately owned, limiting the availability of comprehensive public data on costs and performance.

Millman and New offered to return with materials and workshops; Millman also said the advocacy group 10 4 CT convenes regular meetings and can help towns form working groups. The committee did not take formal action beyond asking for the presentation materials and recording; Millman said he would share links and resources discussed during the meeting.

The committee adjourned after subsequent agenda items. The presentation and Q&A are expected to inform any next steps should Simsbury choose to pursue a working group or host a public workshop.