A landmark project with major implications for how Americans could cleanly heat and cool their homes broke ground in Framingham, Massachusetts, on Monday.
Eversource, the largest gas and electric utility in New England, began construction on its first “networked geothermal” system. The company will connect 32 residential and five commercial buildings in a single neighborhood to underground water pipes, which will draw on the steady temperature of the ground beneath the earth’s surface to air condition and heat the buildings without fossil fuels.
Clean energy advocates across the country are looking to the demonstration as a test of the idea that natural gas utilities can remain in business in a decarbonized world by managing a network of pipes filled with water instead of climate-warming gas.
“I would say it's not just being watched nationally, it's being watched globally,” Zeyneb Magavi, the co-executive director of the Massachusetts-based clean energy nonprofit HEET, told me. Magavi and her partner, Audrey Schulman, dreamed up the idea of transforming gas utilities into geothermal utilities several years ago, and were instrumental in getting Eversource to consider the project.
“If they succeed enough, and I have no doubt they will, they're gonna be the founding install of a new utility that's going to be the foundation of our future energy system,” she said. “It's not that often that you get to give birth to a new utility.”
Geothermal heating systems have been around for nearly a century, and are known for being incredibly efficient. You may have heard of air-source heat pumps, commonly referred to simply as heat pumps, which function like an air conditioner in the summer and a furnace in the winter by transferring heat inside and outside the building. Geothermal heat pumps work similarly, but they use the ground as a source and sink for heat, rather than the ambient air. (They are different, but related to geothermal power plants, which tap into much hotter reservoirs underground to generate electricity.) Since the ground is a more stable temperature than the air, geothermal heat pumps require less energy. Networked geothermal systems have the potential to reduce energy use even more.
Many individual homes and buildings run on geothermal heating systems today, but all the drilling and piping translates into big upfront costs. Magavi told me the spark of HEET’s idea for a neighborhood-wide system dates back to 2008, when she wanted to install geothermal at her own home, but couldn’t afford it. Later, when she joined HEET and began thinking about what a future without gas could look like, she and Schulman discovered geothermal projects elsewhere in the country, such as a small town in Iowa, and a college campus in Colorado, where multiple buildings were linked to the same pipes. The systems didn’t seem all that different from the gas distribution networks they were looking to replace.
The project in Framingham involves building a new set of pipelines alongside the gas system. Each participating building will get a service pipe connecting it to a main horizontal line that runs through the neighborhood, which is in turn connected to a series of vertical lines that go about 500 feet deep. Water runs through the system, bringing heat up from the ground and delivering it to heat pumps inside the buildings in the winter, or absorbing heat from the homes and dumping it back underground in the summer.
Illustration of a networked geothermal systemAnara Magavi/HEET
The whole system is expected to be up and running by the fall. Eversource estimates the project will cost $14.7 million, and has received approval from regulators to pay for it with ratepayer funds, spread across its entire customer base. Participants will not pay any additional fees on top of the cost to run the heat pump equipment on their electricity bill. They will retain their existing heating and cooling systems, and will have the option to go back to them after the two-year pilot period.
Residents could see a 20% reduction in energy costs, according to Eversource, and around a 60% decrease in carbon emissions, taking into account the current electricity supply. The company will be gathering data throughout the pilot to confirm the actual cost, energy, and carbon savings of the project. “We also want to make a strong business case for why this should be done by the utility and why it makes sense for us to be building out systems like this,” said Eric Bosworth, the senior program manager for clean technologies at Eversource.
Magavi and Schulman see networked geothermal as an elegant solution to one of the biggest challenges of tackling climate change: avoiding what’s known as the utility death-spiral. If people begin swapping out their natural gas heaters for electric heat pumps, they will drive up costs for remaining gas customers, which will motivate more people to go electric, and inflate gas bills even more.
Geothermal presents a path for utilities to retain their customers. They already have the expertise to build and manage underground pipelines and heating equipment. And Magavi argues that if utilities take on the up front costs, it would give people more equitable access to clean energy. “You can just sign up with the utility — you don't have to have upfront capital, knowledge, or time,” she said. “That equity of access is something that is necessary for a just transition.”
If geothermal heating and cooling were to really take off, it could also help with another major climate challenge — the electric grid. The switch to electric vehicles and heat pumps is going to require a massive expansion of clean electricity resources and transmission and distribution wires. Widespread adoption of geothermal heat pumps could minimize that buildout. Boswoth told me that geothermal networks could be strategically deployed in areas that are electrically constrained.
Many climate advocates also like the idea because it presents a clear transition opportunity for natural gas workers, like those in the Plumbers and Pipefitters Union that build and maintain gas pipelines. “Networked geothermal systems could be a promising option for providing high road job opportunities to these workers,” Jenna Tatum of the Building Electrification Institute told me.
But that’s one aspect of the promise of networked geothermal that the Framingham project won’t be demonstrating. Eversource hired a third party construction company and hasn’t entered an agreement with any unions yet, although Bosworth said the company was actively engaged with the Pipefitters Union regarding longer-term geothermal plans.
The pilot in Framingham will be the first networked geothermal system operated by a utility, but it definitely won’t be the last. Massachusetts regulators have approved a handful of additional networked geothermal projects to be owned and operated by Eversource and another gas utility, National Grid. New York State is also moving forward on a number of utility-owned pilots. Several other states, like Minnesota, have also passed laws that encourage gas utilities to pursue geothermal.
“We expect that we're going to see a pretty significant pilot proposal in [utility] plans modeled after the work that's been done out East,” Joe Dammel, managing director of buildings for Fresh Energy, a Minnesota-based clean energy nonprofit, told me.
One challenge that’s come up as the idea has taken off is that no one can seem to agree about what it should be called. While the term is “networked geothermal” in Massachusetts, New York is using “thermal energy network.” Magavi said it’s also been referred to as “community geothermal,” a “thermal highway,” an ATL or “ambient temperature loop,” a “heatnet” and a “5G” network. All of this is further complicated by the fact that the terms “geothermal energy,” “heat pumps,” and “district energy,” can all refer to fundamentally different technologies.
“It’s a nightmare,” she told me. She said she’s initiated a campaign with the National Renewable Energy Laboratory and the Department of Energy to set language standards. “There’s a survey currently going out to everyone to ask them what they think about all the different names.”
The Framingham pilot could be significantly expanded if all goes well. HEET collaborated with Eversource to apply for funding from the Department of Energy for a second networked geothermal system in the city that would be connected to the first one, and was recently awarded a $717,000 grant.
Advocates like Magavi hope these projects will turn into a full-on transition strategy for utilities to move away from a business model based on gas or other fuels. At the groundbreaking on Monday, Eversource chairman, president, and CEO Joe Nolan made a bold statement that seemed to support that notion. “As we transition to a carbon-free future, this is going to be the answer for everybody,” he said. “And it’s all starting right here.”
But when I talked to Bosworth, he qualified that at this point the company sees geothermal as one “tool in the proverbial toolbelt.” Like many utilities, Eversource is also exploring the potential to deliver lower-carbon fuels like biogas and hydrogen through its gas lines.
“We want to take a look at any and all potential pathways and really vet them for what is viable, and what works where,” Bosworth told me. “We will use a combined approach to get to our carbon neutrality goals.”
