Energy efficiency has become one of the most effective strategies for cutting costs and carbon emissions. New and effective technologies are always emerging. A recent study highlights the vast potential of geothermal heat pumps (GHPs) to increase energy efficiency in buildings and on the national grid.

The study, “Grid Cost and Total Emissions Reductions Through Mass Deployment of Geothermal Heat Pumps for Building Heating and Cooling Electrification in the United States,” was performed by the Oak Ridge National Laboratory and the National Renewable Energy Laboratory, both of which operate under the federal Department of Energy. Results of the study were published in November 2023.

Although its wordy title certainly lacks efficiency, the study finds that heat pumps have plenty of it. In fact, the study estimates that buildings could save as much as 593 terawatt-hours (TWh) of electricity generation annually with widespread adoption of GHPs. A terawatt is equal to 1 trillion watts of electricity, and 500 TWh is enough to power more than 35 million homes for a year, about 15% of the current annual electricity demand in the United States.

Power is not the only thing heat pumps can save. According to the study, widespread adoption could also avoid seven tons of carbon-equivalent emissions by the year 2050.

The study makes its projections based on an assumption that GHPs will be installed into 68% of existing and new building floor space in the United States by 2050. The overall figure would encompass 78% of residential floor space and 43% of commercial floor space.

As the study notes, “GHPs have traditionally been viewed as a building energy technology” and their ability to lower building energy costs are “well-understood.” However, this analysis also looks at the impact of widespread adoption of the technology on the grid.

The study notes that widespread GHP adoption in the United States could also ease pressure for transmission improvements because they reduce the need for generation capacity, storage and transmission compared to other energy pathways. Specifically, the study projects a reduction in demand for new transmission lines equivalent to 24,500 miles, enough to circle almost the entire globe at the equator.