Building electrification is becoming a major approach in fighting climate change and reducing emissions. As electrical generation becomes cleaner with wind, solar, and hydro, building electrification makes sense. Concurrently, the air-source heat pump market has been on a steady rise with the adoption of inverter-based technology. Though the newer air-to-air heat pumps can keep heating with the refrigeration cycle down to lower outdoor air temperatures there are inefficiencies at these lower temperatures trying to absorb heat from 0°F air.
Geothermal units, or ground-source heat pumps (GSHP), solve the low-temperature issue as the ground is at a constant 50°-60° temperature, providing much better efficiencies during heating and cooling. The largest obstacle to geothermal heat pump adoption has always been the wells and their associated costs. Closed GSHP wells do not require environmental permitting are not that dependent on ground water flow but do not have efficient heat transfer with the ground and, as such, require a lot of well per ton. Many vertical wells would be required for even a modest commercial building. Open-loop GHSP wells provide better heat transfer efficiency but are dependent on considerable local ground water flow, reinjection is very difficult, and they usually require extensive environmental permitting.