When a neighborhood-scale geothermal network came online in Framingham, Massachusetts, two years ago, it was hailed as groundbreaking.

The first-of-its-kind system, owned by the state’s largest utility, Eversource, delivers warm and cool air to some 140 customers through pipes much like the ones that used to carry natural gas to those homes and businesses. But instead of burning fossil fuels to generate warmth, the network draws on emissions-free thermal energy stored in the ground beneath the community. To deliver cool air, the system returns the heat back into the earth.

Supporters say this approach to climate-friendly heating and cooling — geothermal loops, serving entire neighborhoods, owned and operated by utilities — can deliver clean heat, save consumers money, and provide new business opportunities for natural gas companies in states trying to transition away from fossil fuels.

The idea has advanced in Massachusetts largely through the efforts of clean-heat nonprofit Home Energy Efficiency Team, or HEET, and supportive lawmakers and regulators. The country’s first law enabling these systems was passed in the state in 2021, and the Framingham pilot is the only such network currently up and running in the U.S. Construction is slated to begin on a second network in Massachusetts this summer.

However, as more states look for ways to transition away from natural gas for economic and environmental reasons, the idea is catching on fast: Today, 13 states have laws promoting thermal networks, and 11 utility companies nationwide are developing about 30 projects, according to a crowdsourced map created by the Building Decarbonization Coalition. New York and Colorado, especially, are instituting new laws and mandates to encourage the formation of pilot projects.

With momentum building, HEET and its allies contend that this new form of energy delivery requires a structural rethink. Lawmakers and regulators are currently considering a pair of measures that lay out guidelines for who owns the thermal energy beneath our feet, and how consumers should pay for it.

These proposals aim to seize this moment, when the rules of thermal energy delivery are not yet established, to write a playbook that prioritizes affordable service for consumers and good jobs for utility workers over corporate profits. In the face of volatile and rising natural gas prices, it is a chance to change fundamental assumptions about who should receive the benefits of an energy resource, said Zeyneb Magavi, executive director of HEET.

“This is the beginning of the creation of a new business model,” she said. ​“It’s a once-in-many-lifetimes opportunity to get to reimagine and redesign the energy system.”

In March, the state legislature’s Joint Committee on Telecommunications, Utilities, and Energy advanced a bill, sponsored by Rep. Steve Owens (D) and largely authored by HEET, that would establish the existence of a thermal commons. The ​“commons” is an economics concept that refers to resources that are shared among a community with no exclusive private ownership. Think sheep grazing on the town green in days of yore.

The bill would also create a commission that would hone that definition and answer key questions: Who can access the thermal energy under public lands? Are there places where drilling should be prohibited? Do a private landowner’s thermal rights extend to the edge of their property? The panel would, essentially, come up with a set of rules to make sure everyone knows whose geothermal sheep can graze where.

“This can be the basis for future legal thinking,” Magavi said.

Meanwhile Eversource, has proposed a new framework for setting rates for geothermal service, now awaiting approval from utility regulators.

Most utility rates are volumetric — that is, the more you use, the more you pay. But Eversource wants customers to instead pay a flat monthly fee based on the capacity of their heat pumps. A home with a three-ton heat pump, for example, would pay a fixed charge of $10 per month, plus another $14.95 per ton of capacity, for a monthly total of $54.85.

Running the heat or air conditioning more would still increase a customer’s electricity bill — heat pumps run on electricity — but the cost of the warm or cool air itself would remain stable regardless of usage. This model works because customers aren’t paying any fuel costs for the thermal energy being drawn from the ground, so heating more won’t mean more expense for the forthcoming geothermal utilities.

This is the first time state utility regulators have been asked to consider a rate structure for an entirely new utility service in maybe 120 years, said Eric Bosworth, who oversaw the development of the Framingham pilot in his former position at Eversource.

“It’s great for rate transparency,” he added. ​“It makes the energy calculation on what bills will be very straightforward.”

But before these systemic changes can take root, more thermal networks need to come online to demonstrate the potential widely, Bosworth said.

“We need more people putting more pipe into the ground, because that’s when it becomes visible and it becomes real,” he said.

To that end, HEET is dedicated to learning everything it can from each new project, to analyze how effective the networks are and to find ways to improve them. It founded the research initiative Learning From the Ground Up to collect data from the earliest projects. In Framingham, the organization threaded 14 of the 88 boreholes with fiber optic sensors that collect temperature data from the thermal exchanger in order to confirm and better understand the efficiency of the system.

Building public awareness and support will also be vital for widespread adoption. There needs to be thoughtful education and outreach to convince people that thermal systems can be as good as or better than what they’re used to, said Kristin George Bagdanov, associate director of research at the Building Decarbonization Coalition and the author of the newsletter ​“Cheaper Heat.” Some people might be worried about the consequences of a power outage, or concerned about cooking without a gas stove, she said. Some utilities promoting pilot projects have encountered residents who were sure that the whole thing must be a scam, because it promises so much, said Nicole Abene, the Building Decarbonization Coalition’s associate director for New York.

So far, thermal networks have had bipartisan appeal. The Trump administration retained tax credits for geothermal energy when it gutted incentives for other types of renewable energy, and Republican lawmakers have been supportive of the systems in many states. HEET has worked hard to keep the conversation focused on affordability, jobs, and energy independence, rather than solely on the environmental benefits.

“We have to actually stick to the inclusive language and narrative we’ve been using,” Magavi said. ​“The minute we have some of the powers that be step in and use partisan language we’re risking the whole system.”An update was made on May 28, 2026, to include the name of Rep. Steve Owens, who sponsored the bill advanced by Massachusetts’ Joint Committee on Telecommunications, Utilities, and Energy.

Sarah Shemkus

is a reporter at Canary Media who is based in Gloucester, Massachusetts, and covers New England.