U.S. DOE Publishes Five New Ground-Source Heating and Cooling Case Studies Showing Large Cost and Energy Gains

The Department of Energy’s geothermal program has expanded its public catalogue of ground-source heating and cooling deployments with five new, independently documented case studies prepared by the National Laboratory of the Rockies. The additions span diverse building types — a large residential development, K–12 schools, a college campus, a commercial grocery store, and a major airport terminal — showing the technology’s adaptability beyond single-family homes. In one residential community outside Fayetteville, geothermal systems serve roughly 750 homes, offering a model for scaled neighborhood-level adoption. A school district deployment in West Virginia, aggregated across ten upgraded schools, reports an approximately 75% reduction in energy use after switching to ground-source systems, illustrating how school portfolios can drive deep operational savings. At Louisville’s main passenger terminal, a field of boreholes reaching about 500 feet supplies heating and cooling for the terminal; the operators estimate roughly $400,000 in annual energy cost avoidance from the system. A community college campus in New Mexico has cut utility expenditures nearly in half for three campus buildings following installation, while a grocery store in Oklahoma City built with a ground-source system records about one-third lower utility bills than the chain’s earlier location without such technology. Though these projects were not financed by the DOE geothermal office, the documented performance outcomes provide practical data points for facilities managers, procurement teams, and policymakers assessing lifecycle costs and payback timelines. The case studies add to an existing national collection of ground-source project profiles, giving engineers and decision-makers clear comparisons of realized savings, installation scales, and site types. Taken together, the new entries reinforce that ground-source systems can be cost-effective across both small and large facilities when designed and operated to match local loads. The DOE’s expanded database aims to reduce informational friction for organizations weighing decarbonization and resilience investments by offering measured performance rather than modeled projections. For stakeholders focused on municipal or institutional retrofits, these documented outcomes lower uncertainty around expected operational savings and can accelerate project approvals. The body of evidence also highlights the importance of site-specific design — borefield sizing, system integration, and load management — in achieving the reported results.