Ground source heat pumps could bring geothermal heating and cooling to millions of homes in the coming decade, a federal report concludes.
Key Points at a Glance
- Ground source heat pumps harness stable underground temperatures for heating and cooling, outperforming traditional systems.
- Adoption could grow to serve 7 million homes by 2035, easing grid demand and reducing emissions.
- High upfront installation costs remain a significant hurdle despite long-term savings.
- Shared systems for multiple buildings offer a scalable path forward, as seen in pilot projects like the one in Framingham, Massachusetts.
The U.S. Department of Energy (DOE) has released an illuminating report on the potential of ground source heat pumps (GHPs) to transform energy consumption across the United States. These efficient systems, which utilize geothermal energy to heat and cool buildings, could expand from their current presence in just over one million homes to seven million by 2035. Such growth would drastically reduce the strain on the electrical grid, cutting peak demand by 12 gigawatts in the summer and 40 gigawatts in the winter—equivalent to the output of dozens of coal or gas-fired power plants.
Ground source heat pumps differ from the more common air source heat pumps in their ability to tap into consistent underground temperatures. These systems use wells drilled hundreds of feet into the earth or pipes buried near the surface to exchange heat, maintaining year-round efficiency regardless of external weather conditions. This stability allows them to operate at significantly higher efficiency levels than traditional HVAC systems, even during extreme temperature swings.
“They essentially offer this cost-effective solution for heating and cooling,” said Lauren Boyd, head of the DOE’s Geothermal Technologies Office. With heating and cooling accounting for a substantial portion of global energy consumption, this technology presents an opportunity to make meaningful reductions in energy use and emissions.
Despite their benefits, GHPs face a significant barrier in their upfront costs. Residential systems average $19,000 after federal tax incentives. However, these expenses are mitigated over time through energy savings, with many homeowners recouping their investment in a decade or less. Federal tax credits currently offset 30% or more of installation costs, providing a critical boost to adoption.
Expanding the technology to include thermal energy networks—where multiple buildings share a heating and cooling system—could further drive cost reductions. Universities and other large institutions have already successfully implemented such systems, and utility companies like Eversource Energy are piloting neighborhood-scale projects. These collaborative systems also align with decarbonization goals and could offer a scalable model for future growth.
The DOE’s report is part of its Liftoff series, an initiative aimed at accelerating clean energy technologies to widespread commercialization. Ground source heat pumps join other highlighted innovations like offshore wind energy and clean hydrogen. The report emphasizes that achieving widespread adoption will require not only financial incentives but also public awareness and skilled labor development.
William Hinkle, a spokesperson for Eversource, praised the report’s projections, noting that the geothermal industry’s maturity will likely lead to reduced costs. “Geothermal is still a relatively small industry with significant room for growth,” he said, adding that lessons learned from pilot projects could help achieve the annual growth rate of 10% needed to meet the report’s goals.
Advocates like Zeyneb Magavi, executive director of HEET, believe the current momentum could lead to adoption rates surpassing the DOE’s projections. The report, she said, “makes the potential of this market visible,” potentially marking a tipping point for the technology.
Thermal energy networks could also be instrumental in achieving these goals. These systems—already under exploration by utility companies—offer significant decarbonization potential while benefiting the electrical grid with their low energy demands.
Ground source heat pumps present a viable path toward a cleaner, more energy-efficient future. As the DOE’s report highlights, addressing challenges like high installation costs and limited public awareness could unlock the potential of this transformative technology. With a combination of policy support, technological innovation, and collaborative projects, GHPs could play a vital role in meeting global climate goals.
