Geothermal heating and cooling technologies can reduce peak electricity demand, increase resilience, and lower ratepayer energy bills. By 2050, the technical potentiali for geothermal heating and cooling systems equates to up to ~80 million homes (~200 million refrigeration tonsii) across residential and commercial buildings in the United States; however, actual adoption will likely be lower. At full deployment, summer and winter peak demand could be hundreds of gigawatts (GW) lower than for a scenario with less efficient building electrification at similar levels. The peak demand reduction could potentially lower energy payments by tens of billions of dollars nationally due to grid system cost savings, with average annual savings in the hundreds of dollars for homeowners and renters (ES Figure 2).
Geothermal heat pumps (GHPs) operate similarly to air-source heat pumps (ASHPs)—using a refrigeration cycle to move heat for heating or cooling—but use the ground as a source and sink of heat, rather than outdoor air. In many cases or regions, GHPs are more efficient, have lower operating costs, and confer greater grid benefits than traditional heating and cooling alternatives. The GHP market share currently represents just 1 percent of installed residential heating compared to 13 percent for ASHPs (see Executive Summary (ES) Figure 1). While the thermodynamic principles of GHPs and ASHPs are the same, the ground provides a more constant temperature for heat exchange than outdoor air, increasing the efficiency of GHPs.
Deployment of GHPs with ASHPs and other energy efficiency measures can achieve key energy resilience, energy affordability, and national decarbonization goals. This Liftoff Report focuses on geothermal heating and cooling that employs heat pumps, rather than direct heat, and the potential to broaden consumer adoption, accelerate installation rates, and substantially improve market depth in the United States. Widespread deployment of GHPs and integration with smart, grid-connected grid-edge technologies also provides peak load reduction, load shifting, load shaping, and demand flexibility benefits that help avoid distribution and bulk system upgrades, with savings that accrue to both utilities and ratepayers. GHPs also help meet national energy efficiency goals as set forth in the DOE’s National Blueprint for the Buildings Sector, including a threefold increase in demand flexibility and a doubling of energy efficiency, particularly for buildings such as large commercial buildings, campuses and multifamily buildings.
