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Get a Free QuoteNH granite bedrock pushes geothermal costs to $18,000–$50,000+. Full cost breakdown, ROI vs oil & propane, NHSaves rebate eligibility, and when air-source is the smarter choice.
Federal Section 25C tax credit expired Dec 31, 2025. Honest ROI analysis below.
Honest Bottom Line Before You Read
Geothermal works exceptionally well in NH from an energy standpoint — stable 50°F ground means consistent efficiency all winter. The problem is cost: NH granite bedrock makes drilling expensive ($15–$25/ft), and most NH homes pay back geothermal systems in 15–25 years. A cold-climate air-source heat pump (Mitsubishi, Fujitsu) costs $12,000–$22,000 and pays back in 6–10 years. Geothermal makes sense in specific situations — we cover exactly when below.
A geothermal (ground-source) heat pump transfers heat between your home and the ground rather than the outdoor air. Underground, NH soil and bedrock maintain a constant temperature of roughly 50°F year-round — much warmer than a January night in Concord (-10°F) and cooler than a July day in Manchester (90°F).
A loop of fluid-filled pipe buried underground absorbs heat from the 50°F ground in winter and delivers it indoors via a heat pump unit. In summer, the process reverses — the system rejects heat from your home into the cooler ground, providing air conditioning.
Because the ground is always closer to a comfortable temperature than the air, geothermal heat pumps achieve higher efficiencies (COP 3.5–5.0) than even the best air-source units (COP 2.5–3.5 in cold conditions).
Which system works in NH depends on your lot size, soil depth, and whether you have an existing well.
Depth / Scope
200–500 ft per bore hole
Drilling/Excavation
$15–$25 per foot
Total Drilling Cost
$9,000–$25,000+ for drilling alone
NH Context: NH granite bedrock is hard but consistent. Drilling is slower and more expensive than in softer soils. Most NH geothermal installs use vertical bore.
Pros
Cons
Depth / Scope
4–6 ft below frost line
Drilling/Excavation
$2,000–$5,000 for excavation
Total Drilling Cost
$15,000–$28,000 total installed
NH Context: NH lots tend to be smaller and NH soil is often rocky and shallow before hitting bedrock. Horizontal loops are rare in southern NH but feasible in rural areas with large flat lots.
Pros
Cons
Depth / Scope
Uses existing or new drilled well
Drilling/Excavation
$8,000–$15,000 if new well needed
Total Drilling Cost
$18,000–$35,000 total installed
NH Context: NH groundwater is stable at roughly 50°F year-round. DES permits required for discharge. Some areas restrict open-loop discharge to surface water. Check with your town and DES.
Pros
Cons
New Hampshire is part of the Appalachian mountain chain, underlain by granite and metamorphic schist from the Acadian orogeny 350–400 million years ago. This geology is beautiful — and expensive to drill through.
New Hampshire
$15–$25/ft
Granite/schist bedrock. Diamond-tipped bits, slow progress.
Massachusetts / RI
$12–$20/ft
Mixed geology. Some areas softer than NH but still challenging.
Midwest / South
$8–$14/ft
Clay, sand, softer limestone. Much faster drilling progress.
Example: A 350 ft vertical bore in NH costs $5,250–$8,750 in drilling alone. A typical NH home needs 2–3 bore holes = $10,500–$26,250 just for the ground loop. Add the heat pump unit, loop pipe, header, pump, and labor: total installed $28,000–$50,000+.
In many southern NH towns (Nashua, Manchester, Salem), you hit granite ledge within 6 inches to 2 feet of the surface. This makes horizontal loops impossible and means vertical bore is the only closed-loop option. Your installer must have a track record drilling in NH ledge conditions — not all geothermal contractors do.
NH has abundant groundwater from fractured granite aquifers. Many NH homes already have drilled wells. If your well yields 3+ GPM sustained and you can manage discharge water (return well, leach field, or surface discharge with DES permit), open-loop geothermal can save $8,000–$15,000 in drilling costs vs. closed loop.
Based on NH fuel prices: heating oil at $3.69/gal, propane at $3.62/gal, electricity at $0.25/kWh (Eversource). All scenarios assume a 2,000 sq ft home with average NH heating loads.
Current Annual Cost
$2,800
Geothermal Annual Cost
$850
Annual Savings
$1,950
Net System Cost
$30,750
750 gal oil/yr at $3.69/gal. Geothermal at COP 4.0, $0.25/kWh.
Current Annual Cost
$2,700
Geothermal Annual Cost
$850
Annual Savings
$1,850
Net System Cost
$30,750
750 gal propane/yr at $3.62/gal. Geothermal at COP 4.0, $0.25/kWh.
Current Annual Cost
$2,800
Geothermal Annual Cost
$850
Annual Savings
$1,950
Net System Cost
$43,750
Hard granite, 400+ ft drilling. Cost escalation common in NH.
Current Annual Cost
$1,050
Geothermal Annual Cost
$850
Annual Savings
$200
Net System Cost
$20,000
Extra $20K for geothermal saves only $200/yr more than air-source. 100-yr payback on incremental cost.
Key takeaway: Even replacing oil at $3.69/gal — the most favorable scenario — geothermal payback in NH is typically 15–25 years. A cold-climate air-source heat pump pays back in 6–10 years replacing oil and provides similar comfort. The geothermal premium rarely makes financial sense unless you are replacing electric resistance heating (Enhanced NHSaves tier).
| System | Upfront Cost | NHSaves Rebate | Annual Heating | Payback |
|---|---|---|---|---|
| Air-Source Heat Pump (whole home) | $12,000–$22,000 | Up to $1,250 | $1,050 | 6–10 yrs |
| Geothermal Heat Pump (vertical bore) | $25,000–$50,000+ | NHSaves: Possibly; Section 25C: Expired | $700–$950 | 15–25 yrs |
| Geothermal Heat Pump (open loop) | $18,000–$35,000 | NHSaves: Possibly | $700–$900 | 12–20 yrs |
| Heating Oil Furnace | $4,000–$8,000 | None | $2,800 | N/A (no fuel savings) |
| Propane Furnace | $4,000–$7,000 | None | $2,700 | N/A |
Assumptions: 2,000 sq ft NH home, Eversource territory ($0.25/kWh), oil at $3.69/gal, propane at $3.62/gal. Geothermal assumes COP 4.0. Air-source assumes COP 3.0.
NHSaves rebates for heat pumps are primarily designed for air-source systems, but ground-source units may qualify. Verify before you commit.
$250/ton, max $1,250
Replacing oil, propane, or gas. ENERGY STAR Cold Climate certified. NHSaves qualified installer.
$1,250/ton, max $6,250
Replacing electric resistance heating. Pre-verification BEFORE installation. Must be approved by NHSaves first.
Federal 25C Tax Credit: EXPIRED
Section 25C federal tax credit: EXPIRED December 31, 2025. $0 credit available for 2026 installs.
NHSaves does have some ground-source heat pump incentives, but qualification rules change. Contact NHSaves (1-855-247-2833) before committing to any geothermal project to confirm current rebate availability and pre-approval requirements.
Geothermal is not right for every NH homeowner. Here is a clear-eyed assessment of when it pencils out.
Building new? Geothermal can be integrated during construction when trenching and drilling disrupt less. Budget flexibility matters most.
If your NH home already has a high-yield drilled well, open-loop geothermal saves $8,000–$15,000 in drilling costs vs. a new vertical bore.
If you heat with baseboard electric at $0.25/kWh, geothermal can cut your heating bill by 60–70%. NHSaves Enhanced tier ($6,250 max) may apply.
Geothermal makes financial sense only with a very long payback. If you plan to sell in 5–10 years, air-source will serve you better.
If you are replacing a recently installed oil or propane system and have a limited budget, air-source delivers 80% of the savings at 30–40% of the cost.
Horizontal loops require space you likely do not have. Vertical bore on a small lot with granite bedrock can push costs above $45,000. Air-source is the practical choice.
How many vertical bore installs have you done in NH granite/ledge conditions specifically?
What drilling rate (ft/hr) do you estimate for my site, and what drives that estimate?
Is my lot a candidate for open-loop? What is the yield test process?
What permits do you pull (DES, local building)? Who is responsible for each?
What is included in the quote — loop, header, heat pump unit, distribution, labor?
What happens if you hit unexpected ledge depth or drilling complications — is there a change order clause?
Are you NHSaves qualified? Will this unit appear on the NHSaves approved equipment list?
What is your warranty on drilling, loop pipe, and the heat pump unit separately?
Geothermal heat pump systems in New Hampshire typically cost $18,000 to $50,000 or more installed. The wide range reflects NH geology: granite bedrock requires diamond-tipped drilling at $15 to $25 per foot, and a typical NH home needs 300 to 400 feet of bore depth per hole. An open-loop system using an existing high-yield well can come in at the lower end ($18,000–$35,000), while vertical closed-loop systems on hard granite lots often reach $35,000–$50,000 or more.
Geothermal is more efficient (COP 3.5–5.0 vs. 2.5–3.5 for air-source), but the cost difference rarely makes financial sense in NH. A geothermal system costs $25,000–$50,000 vs. $12,000–$22,000 for a cold-climate air-source heat pump. The extra $15,000–$30,000 in geothermal cost saves only $100–$300 more per year in energy costs vs. a quality air-source system. Simple payback on the incremental cost can exceed 50 years. For most NH homeowners, cold-climate air-source heat pumps from Mitsubishi, Fujitsu, or LG offer better financial returns.
New Hampshire ground temperature at depth (below the frost line) stays around 50°F year-round. This consistent temperature is the foundation of geothermal efficiency: a heat pump extracts heat from 50°F ground even when outdoor air is -10°F. By contrast, air-source heat pumps extract heat from cold air, which reduces efficiency on the coldest days. Ground temperature in NH is similar across the state (47°F to 53°F), so geothermal performance is consistent from southern to northern NH.
New Hampshire sits on Appalachian granite and schist — some of the hardest bedrock in the Northeast. Drilling through granite requires diamond-tipped rotary bits and significantly more time than drilling through clay, sand, or softer limestone found in southern states. NH drilling rates run $15 to $25 per foot vs. $8 to $15 per foot in softer-soil states. A 350-foot bore hole costs $5,250 to $8,750 in drilling costs alone, and most NH homes need two or more bore holes.
NHSaves has historically offered some rebates for ground-source heat pumps, but qualification requirements and available funding change annually. As of 2026, contact NHSaves directly at 1-855-247-2833 before committing to any project to confirm rebate availability and pre-approval requirements. The federal Section 25C tax credit for geothermal expired December 31, 2025, and provides $0 for 2026 installations.
Vertical closed-loop geothermal systems require a well/boring permit from the NH Department of Environmental Services (DES). Open-loop systems additionally require a groundwater withdrawal permit and a discharge permit if water is returned to a surface water body. Building permits from your town are also required for mechanical work. Permitting timelines vary by municipality — budget 4 to 8 weeks for DES well permits and 2 to 4 weeks for local building permits.
Ground loops (the pipes buried underground) last 50 years or more and are considered essentially permanent. The heat pump unit inside the home lasts 20 to 25 years — about twice the lifespan of an air-source heat pump (10 to 15 years) or a furnace (15 to 20 years). This longer equipment life partially offsets the higher upfront cost over a very long ownership horizon.
Possibly, but your well must meet specific requirements. Open-loop geothermal typically requires 3 to 5 gallons per minute (GPM) of water flow at sustained use. Many NH drilled wells yield 1 to 3 GPM — enough for household use but potentially insufficient for open-loop geothermal. A well yield test is required before committing. You also need a plan for discharge water: returning it to a pond, stream, reinjection well, or leach field, each with different permit requirements from NH DES.
For most NH homeowners, a cold-climate air-source heat pump delivers 85–90% of geothermal's energy savings at 30–40% of the cost. Talk to NuWatt about which system matches your home, lot, and budget.