Maine has 24 verified geothermal contractors and is one of the strongest heating-dominated geothermal markets in the country — Efficiency Maine's rebate framework rivals Massachusetts' Mass Save in residential heat pump support. Federal §25D was terminated by the One Big Beautiful Bill Act (P.L. 119-21) on December 31, 2025, but Central Maine Power (CMP) + Versant Power rebates and the §48 commercial credit keep ground-source competitive.
- 24 listed contractors
- 21 cities covered
- ★ 3.7 avg rating (274 reviews)
- 2 WaterFurnace dealers
- 1 IGSHPA-certified
Top Maine cities for geothermal contractors
Coverage spans Portland, Bangor, Augusta, Lewiston-Auburn. Browse contractors by city below.
Featured Maine geothermal contractors
Maine geothermal incentives in 2026
The federal §25D Residential Clean Energy Credit was terminated for new residential expenditures completed after December 31, 2025 by the One Big Beautiful Bill Act (P.L. 119-21). 2025 installations carry forward via IRS Form 5695. Maine homeowners benefit from:
- Central Maine Power (CMP) + Versant Power — Efficiency Maine — independent state-level energy efficiency program with significant rebates for ground-source heat pump installations.
- Efficiency Maine heat pump rebates — among the most generous in New England. Verify current per-ton rates with Efficiency Maine before signing.
- Federal §48 commercial credit remains active through 2034 with phase-down; widely used in third-party-owned residential leases.
For state-by-state matrix see geothermal rebates by state, and use our geothermal tax credit calculator.
Maine climate, ground conditions, and permits
Maine climate is humid continental (Dfb). Ground temperatures at typical loop depth stay around 44–48°F. glacial drift over granite and schist bedrock. Drilling encounters bedrock relatively shallowly across most of the state.
Closed-loop installations require a Maine DEP (Department of Environmental Protection)-licensed well driller, a Maine mechanical contractor licensing (handled at municipal level), and a local building permit covering the indoor unit and electrical service. For permit specifics see our geothermal permit lookup.
Frequently asked questions
How much does geothermal cost in Maine?
A typical 3-ton residential system in Maine runs $20,000 to $34,000 installed depending on loop type, soil conditions, and location. Utility rebates from Central Maine Power (CMP) + Versant Power reduce out-of-pocket cost. Federal §25D no longer applies to 2026 residential installations.
Do I need a permit for geothermal in Maine?
Yes. Closed-loop installations require a Maine DEP (Department of Environmental Protection)-certified well driller, a state-licensed mechanical contractor, and a local building permit covering the indoor unit and electrical service. Reputable Maine contractors handle the full permit pull.
Vertical or horizontal loops in Maine?
Lot size and soil determine loop type. Vertical bores dominate dense suburbs; horizontal loops are cost-competitive on rural lots with adequate land area (1,500–3,000 sq ft per ton). Pond loops work where adequate water access exists. An IGSHPA-trained designer matches loop type to your specific lot, soil, and load.