Throughout the country, neighbors are getting into a new kind of heated exchange—this one isn’t over HOA rules or parking.
Some communities are sharing thermal energy to moderate temps in homes and businesses…this could moderate their bills, too.
How it works: A growing number of geothermal networks are linking buildings through systems of pipes and heat pumps. These harness the steady year-round temperatures several hundred feet underground to pull or dump heat (depending on the season). This is one flavor of thermal energy network, a system that can also rely on nearby water sources.
Reduce, reuse, recycle: Buildings can send their leftover thermal energy back into this system via another set of pipes (which is buried a few feet below street level). For example, a data center with servers that generate lots of heat could help warm a nearby office.
Why it works: “Every building uses different amounts of heat at different times,” said Tristan Schwartzman, director of energy services at engineering firm Goldman Copeland. “Heat transfer between different building usage types is a really great package to deliver energy efficiency.”
In recent years, more than a dozen states have enacted policies to allow (or even require) utility-scale thermal energy networks—often to support emissions reductions targets and curb heating costs.
Some of the utility pilots that are proposed or currently in the works:
National Grid and Con Edison projects throughout New York
An early-stage CenterPoint Energy pilot in Minnesota
A Philadelphia Gas Works network to serve a PA school and rec center
They’re all following in Eversource’s footsteps: As proposed in a rate case, the New England mega-company launched the country’s first utility-operated networked geothermal pilot in 2024. It’s located in the Boston suburb of Framingham, and it was developed in collaboration with local officials and nonprofit Home Energy Efficiency Team. The network connects more than 30 buildings, including commercial and residential customers, over a mile-long pipe system.
Now, the pioneering pilot could double in size. The project has secured $8.6M in DOE funding to expand, pending approval from the MA Department of Public Utilities. This next step could help Eversource show state regulators it can scale the network while bringing down costs, said Nikki Bruno, Eversource’s VP of thermal solutions and operational services.
What’s in it for customers: For many MA households—roughly half of which rely on utility gas for heating—switching to geothermal could curb energy costs by 15-20%. Zooming out, US utility customer benefits could vary by region (depending on the local energy mix).
So, can we swap gas for geothermal? It depends on factors like:
Upfront costs: Eversource’s pilot reportedly took tens of millions to get off the ground (the company covered the construction and home equipment).
Site suitability: What’s under the hood matters, including the depth of bedrock accessible in different locations. Neighborhoods also need a diversity of loads for these networks to be successful.
Community sign-off: Utilities should consider residents’ openness within a given neighborhood.
The takeaway: “Our energy supply is no different than your 401K. I would not put my money in one stock only,” Bruno told us. “I do hope geothermal takes off. Realistically, I think customer choice is always going to exist...we’re here to provide all the options that they want.”