A geothermal (ground-source) heat pump does what an ordinary heat pump does — moves heat in and out of your home — but instead of exchanging that heat with the outdoor air, it exchanges it with the ground, through fluid circulating in buried loops. Because the earth a few feet down stays at a nearly constant temperature year-round (roughly the mid-50s to low 60s °F across North Carolina), the system never fights a 95°F afternoon or a 20°F night the way an air-source unit does. The result is the most efficient heating and cooling available. The catch is cost — and, as of 2026, the loss of the federal credit that used to soften it. Here’s the honest picture.
How it works
The heart of the system is a loop of pipe buried in the yard (horizontal trenches) or in deep boreholes (vertical), or laid in a pond, filled with water or antifreeze. In summer, the indoor heat pump pulls heat from the house and dumps it into the cooler ground through the loop; in winter it pulls heat out of the ground and brings it inside. Because the ground temperature is so stable, the heat pump works with a small, constant temperature difference instead of a large, swinging one — which is why its coefficient of performance stays high in exactly the conditions where an air-source heat pump strains.
Indoors, a geothermal system looks much like a conventional one — an indoor unit connected to your ductwork — and it can also provide some free water heating as a byproduct in cooling season.
Cost in North Carolina
Geothermal’s price is dominated by the ground loop. Installed systems for a typical home commonly run several times the cost of a comparable air-source heat pump, with vertical (drilled) loops costing more than horizontal (trenched) ones. Soil, rock, lot size and drilling access all move the number, which is why quotes vary so widely and why you should get a site-specific assessment rather than trusting a national average.
The offset used to be the federal 25D Residential Clean Energy Credit, worth 30% of the full geothermal cost with no cap. That credit expired December 31, 2025 and, as of this writing, has not been reinstated. This is the single most important fact for anyone considering geothermal in NC in 2026: the biggest incentive is gone. What remains are utility programs — some electric cooperatives (Blue Ridge Energy, for example) offer modest geothermal rebates — and general efficiency programs. Check how NC incentives stack for the current landscape, and confirm anything before you sign.
When it makes sense — and when it doesn’t
Geothermal is worth a serious look if: you plan to stay in the home for decades (the payback is long but the loop lasts 25–50+ years); your energy use is high; you have land suitable for a loop; you’re building new construction where trenching is cheap; or you place a high value on the quiet, the durability and the very low operating cost.
An air-source heat pump is probably the better call if: you’re cost-sensitive on the upfront number; you may move within 10–15 years; you’re on a small lot; or you simply want the best value for a standard NC home. Modern variable-speed air-source heat pumps have narrowed the efficiency gap in a mild climate like ours, and they qualify for the Energy Saver NC rebates that make them dramatically cheaper for eligible households.
Choosing a contractor
Geothermal is specialized. The heat pump itself is Heating Group 3 (H-3) work, but the loop field involves excavation or well drilling and system design that a general HVAC contractor may not do. Look for a contractor with specific geothermal experience (the International Ground Source Heat Pump Association accredits installers), ask how many loop fields they’ve installed, and get the Manual J load calculation — sizing matters even more when the loop is sized to match. Then verify the license as you would for any system.