Question 1

Is geothermal heating worth the cost?

Accepted Answer

Geothermal heat pumps are worth the cost in climates with extreme winters where ground temperature advantage is large, in homes with high heating loads, and when the 30% federal ITC applies. They are most cost-effective when installed during new construction (cheaper to trench then) or when the existing system needs full replacement. In mild climates, cold-climate air source heat pumps offer similar performance at much lower upfront cost.

Question 2

What is the difference between geothermal and air source heat pumps?

Accepted Answer

Air source heat pumps (ASHPs) extract heat from outdoor air and are simpler, cheaper to install ($6,000–$18,000), and work well down to -13°F with modern cold-climate models. Geothermal heat pumps (GHPs) extract heat from the ground (which stays 50–60°F year-round), achieving higher efficiency (COP 4–5 vs 2–4 for air source) but cost significantly more to install ($15,000–$40,000) due to ground loop drilling or trenching.

Question 3

What is the payback period for a geothermal heat pump?

Accepted Answer

Geothermal heat pumps typically pay back in 8–15 years vs a gas furnace and 10–20 years vs an air source heat pump, based on energy savings alone. After the 30% ITC and any state/utility rebates, net cost is $10,500–$28,000. At $300–$800 in annual savings over an air source heat pump, the payback is long. Geothermal makes the strongest financial case when ground loops can be shared across multiple systems or when heating loads are very high.

Geothermal vs Air Source Heat Pump Calculator