Description: The implementation of networked geothermal, also referred to as community geothermal and geothermal districts, began in the United States on college campuses such as Ball State University in Muncie, Indiana in 2009. The concept has grown in popularity as communities across the world seek solutions to rapidly decarbonize existing buildings and facilitate heating of new buildings without use of fossil fuels. Individual communities are moving forward with their own programs supported by utility partnerships, state legislation, and federal grants.

Geothermal or ground-source heat pumps utilize the relatively constant temperatures beneath Earth’s surface to heat and cool buildings, transferring heat from buildings into the ground during the summer and from the ground into buildings in winter. The district-wide scale of geothermal network systems enables the ‘trading’ of energy from one building to another, enhancing the system’s overall performance. Geothermal systems are one of the most viable means of reducing or eliminating the need for fossil fuel combustion in buildings or campuses as well as reducing overall energy requirements for heating and cooling buildings. Additionally, such systems demand lower water consumption and reduce operating and maintenance costs, especially the costs of handling coal and disposing of coal ash in cases where coal-fired boilers are decommissioned.

Many college campuses throughout the U.S. have implemented their own variations on the Ball State University geothermal heat pump system ranging in scope from just a few buildings to nearly all buildings on campus. Geothermal heat pump systems are also increasingly being implemented in private sector developments, with proponents of the technology advocating for the growth of community heat pump networks to utilize geothermal energy to its fullest potential.

In June of 2023, the city of Framingham, Massachusetts worked in partnership with the investor owned utility Eversource to begin construction of a networked system supporting 40 buildings including residences, businesses, and the local fire station, with construction concluding in the winter of 2023. The concept originated with the nonprofit organization Home Energy Efficiency Team [HEET], who pitched the idea to Everource in 2017 with the reasoning that centralized utility providers are better able to shoulder the cost burden of switching to geothermal than individual homeowners. The Framingham project is expected to cost $14.7 million and will leverage the infrastructure model native to utility projects where costs are distributed to ratepayers over time rather than as a one-time bill. While this is currently the first utility-backed networked geothermal pilot, the model is readily expanding. Nearby in Lowell, MA, the utility National Grid broke ground on a geothermal project at the University of Massachusetts in April 2023; in January 2024 plans were announced for a similar geothermal pilot project in a Boston affordable housing community of 346 households.

At the state level, Massachusetts is pushing for the utility-driven model of networked geothermal through their landmark 20-80 Department of Public Utilities order, which formalizes the need to transition away from gas and requires utilities to begin pilot projects accordingly, including networked geothermal. “By 2026, each gas utility company must also propose at least one pilot to decommission an area of its system with pressure/reliability issues, leak-prone pipe, and/or environmental justice populations.” Similar legislative actions encouraging district heating systems have been passed in New York (requiring utility pilots) and Illinois (district energy zoning).

Additionally, in July of 2022, the federal Energy Efficiency and Renewable Energy Office under the Department of Energy made $13 million available for community geothermal heating and cooling projects, supporting eleven communities across ten states: Ann Arbor, MI, Chicago, IL, Duluth, MN, Framingham, MA, New York City, NY, Wallingford, CT, Carbondale, CO, Middlebury, VT, Seward, AK, Shawnee, OK, and Nome, AK. These communities will all complete phase one to design appropriate systems before a sub-group is selected for phase two, deployment. The proposed programs vary in their specific approach, but tend to include a range of residential and municipal buildings. All proposed projects are aligned with the federal Justice 40 initiative.

According to the National Renewable Energy Laboratory (NREL) the proposed Carbondale, CO project will install a geothermal heat pump system that will “support a net-zero district and will heat and cool several key buildings in the community, including school district offices, a library, 20 affordable housing units, a high school, a center for nonprofits, and townhomes. In addition, the project team is also taking into consideration what this transition will mean for the local workforce.”

As one of the first projects of its kind, Ball State University has demonstrated the benefits of networked geothermal. The university successfully replaced four aging coal-fired boilers with a campus-wide geothermal heat pump heating and cooling system. Built in two phases from 2009 to 2014, Ball State’s district-scale geothermal heat pump system heats and cools 47 buildings, amounting to an impressive 7.5 million square feet of coverage. The project reduced campus-wide carbon emissions by approximately 50%, and continues to save over $2 million annually on operation costs. Emissions attributed to the campus are expected to be further reduced as Ball State explores opportunities for virtual power purchase agreements with developers of solar or wind projects both nearby and in other parts of the country.

Goal: 

• Reduce carbon dioxide (CO₂) emissions.
• Reduce energy consumption.
• Transition away from fossil fuels for heating and cooling buildings.