June 25, 2024
Government officials from Michigan to Mongolia have made pilgrimages to a Boston suburb for a firsthand look at an underground geothermal energy project aimed at lowering utility bills and meeting decarbonization goals.
Examining a geothermal network of pipes and pumps in Framingham, Massachusetts — identified by purple markings on the street in contrast to the blue of water pipes and yellow of gas — has been high on the list for the dozens of state legislators, mayors, labor unions, and activists since April 2023. That was when the U.S. Department of Energy awarded funds to communities in 10 states to design or expand networks that deploy ground-based geothermal energy to heat and cool residential and commercial buildings in entire neighborhoods.
It's such a steady stream of people that Zeyneb Magavi, co-executive director of HEET, a nonprofit climate solutions incubator, jokes that "we're going to put down purple bricks on the route that they walk," evoking Boston's redbrick Freedom Trail that links historical sites for tourists.
Networked geothermal is an efficient renewable energy source that uses the ground's constant temperature of 55 degrees to provide low-cost, carbon-free heating and cooling to buildings through an underground network of water pipes. The underground temperature serves as a heat source during winter and transfers indoor heat to the ground for cooling during the summer. Ground-source heat pumps in buildings circulate warm and cool air as needed.
A 3D model of a geothermal energy system, like this one created by University of Michigan students for Ann Arbor, is one way to help communities visualize how the process works. Photo by Dave Brenner/University of Michigan School for Environment and Sustainability.
The Framingham tours have enabled people from other states — like Missy Stults, the director of sustainability and innovations in Ann Arbor, Michigan — to explore the viability, utility, and practical realities of a networked geothermal system. "It really galvanized a lot of our current thinking and strategy in Ann Arbor," she says.
The project is also poised to expand. Framingham is among 11 urban and rural communities from Alaska to Vermont that are sharing $13 million in Energy Department funding to extend, update, or design geothermal for community heating and cooling. The projects are part of President Biden's Justice40 initiative, which seeks to have 40 percent of the benefits from these kinds of investments flow to disadvantaged communities, particularly those overburdened by pollution. The DOE will select a subset of projects later this year.
Exploring U.S. geothermal energy use
While some cities are getting their first look at how to tap into geothermal heat, the technology has been in use for over a century. In 1892, as Boise, Idaho, diversified beyond gold mining, it pioneered the use of geothermal energy to heat homes and the recreation center. Today, Boise officials claim to operate the largest municipal geothermal system in the country, heating more than 90 downtown buildings.
Another early adopter was the Citizen Potawatomi Nation (CPN) in Shawnee, Oklahoma, which received an Energy Department grant last year to update its existing system with a hybrid solar-geothermal design. The CPN has been using geothermal since 2005 when it converted its 30,000-square-foot cultural heritage center from natural gas, says James C. Collard, CPN's director of strategic and economic development.
"If you look at it historically, Indigenous people[s] have been environmentalists forever. It's part of the culture to care for the environment. It is really not unusual for tribal governments to explore these kinds of avenues."—James C. Collard, Director of Strategic and Economic Development, Citizen Potawatomi Nation
Using geothermal energy in Shawnee fits into the philosophy of tribal cultures that take a holistic approach to how they use the land and protect it for future generations. "If you look at it historically, Indigenous people[s] have been environmentalists forever," Collard says. "It's part of the culture to care for the environment. It is really not unusual for tribal governments to explore these kinds of avenues, including solar and wind. It's part of the development philosophy in the nation."
The system that CPN is designing now will serve 37 tribal residential units and three large-scale commercial buildings: a health clinic, a recreational center, and an after-school learning center. "The system will provide 100 percent of the heating and cooling for these buildings," according to Li Song, the project manager, and a professor of aerospace and mechanical engineering at Oklahoma University, one of the project's partners. The team is adding a solar farm into the design to determine if that can be an electricity source to run the required heat pumps inside the buildings.
Two towns in Alaska — Nome and Seward — also are designing geothermal systems with federal funding.
In Nome, Kawerak, a nonprofit tribal consortium serving the Inupiaq and Yupik peoples, among others, is designing a district-wide system to provide space heating and domestic hot water to buildings and cooling for food storage in this remote northwestern part of the state.
Seward's city officials are working to harness the thermal potential of Resurrection Bay's shoreline to heat public buildings downtown. In its Energy Department proposal, Seward officials said they hope to reduce dependency on heating oil and lower carbon dioxide emissions while providing more than 90 percent of the heat needed for half of the city's public buildings, including city hall, an annex, the library, and a museum. In a presentation to town officials, civil engineer Andy Baker, the project designer, says, "Seward has enough heat in the bay to heat the whole town easily."
Community engagement is essential to their success. Seward has held regular public forums to describe the city's approach to renewable energy. Besides providing heat to buildings, Seward also has plans to heat the sidewalks in winter to make them safer, says Mary Tougas, a volunteer on the city's heat loop project.
Other ways to explain the concept to the public — particularly for those who can't make the trek to Boston, Boise, or Shawnee — include a 3D model, like one built by students at the University of Michigan's Center for Sustainable Systems, to help visualize how geothermal works. The model can sit on the kitchen table in someone's home to provide "upfront transparency" in lower-income neighborhoods about the design and the new appliances needed to transition to thermal energy, Stults says. "We tried to be very intentional by having conversations earlier rather than later to avoid surprises." For example, if a homeowner finds out later they need to purchase an air handler and they refuse, "your project is dead."
A crew ties loops together at a manifold vault beneath the Farley lot pump house location in Framingham, Massachusetts. Images courtesy of Eversource Energy.
The May 2024 geothermal energy neighborhood pilot project map. The second phase includes more than three dozen buildings with economic and ethnic diversity.
Planning for what's next
In June, Eversource, a utility company in Massachusetts, expects to begin providing emissions-free heating and cooling for 140 customers in an environmental justice community that includes multi- and single-family low-income housing and commercial buildings. The pilot project — which has involved the Framingham and HEET — was approved by the Massachusetts Department of Public Utilities in late 2020.
For Framingham's second-phase design funded by the Energy Department, Eversource plans to expand the pilot project to more than three dozen buildings in an adjacent neighborhood with both economic and ethnic diversity. "For the second phase, there really was a focus on the municipal buildings and making sure we understood the heating and cooling loads very carefully," said Eric Bosworth, a project manager at Eversource.
In general, he notes that a major consideration for cities planning to install networked geothermal in residential neighborhoods is the wide variety of heating and cooling systems in the housing stock. "We see multiple different types of systems in buildings," Bosworth says. "Some folks have hydraulic baseboards, some have forced air, some have steam systems. That becomes one of the biggest challenges and a cost driver, figuring out how are we going to convert all of these various systems of various ages over to ground-source heat pumps on the inside. Each building is like its own little puzzle to solve."
As Framingham gets set to turn on the geothermal tap, it expects to continue receiving visitors from groups like The World Bank, International Finance Corporation, Harvard University, and elsewhere that want to see the reality of the planet's natural ability to heat and cool buildings in whole neighborhoods.
"The overwhelming feedback that we get from seeing it is that it's real and doable," Magavi says. "It's just pipes and pumps and suddenly this whole community can be combustion-free with zero emissions and lower cost."
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