In New Hampshire, a 4.4-kW system for an average home costs about $12,672 after incentives in 2026, saves about $1,267 in the first year and pays back in 9 years.
| Item | Amount |
|---|---|
| Solar, 4.4 kW × $2.88/W | $12,672 |
| Federal credit (0%) | $0 |
| Net cost | $12,672 |
| Scenario | Net cost | Year-1 savings | Payback | 25-yr net |
|---|---|---|---|---|
| State averages (above) | $12,672 | $1,267 | 9 yr | $30,525 |
| Rates rise 5.6%/yr (2020–25 pace) | $12,672 | $1,267 | 8.3 yr | $47,989 |
| Rates stay flat | $12,672 | $1,267 | 10.2 yr | $17,176 |
| Survey price $3.7/W (LBNL) | $16,280 | $1,267 | 11.3 yr | $26,917 |
| Add 13.5-kWh battery | $27,374 | $1,401 | 16.1 yr | $20,398 |
| Size to 100% of use instead | $17,741 | $1,774 | 9 yr | $42,735 |
Verdict: at average New Hampshire numbers, solar is a solid investment in 2026 — payback takes 9 years, leaving you $30,525 ahead after 25 years. The main reasons: electricity that costs more than in all but 8 states; weak sun (the 6th-lowest yield of 51); export credits below retail (exports earn ~75% of retail), so only the solar you use yourself earns full value. Pay cash if you can: Berkeley Lab found loan-financed systems priced about $1.50/W above cash installs in 2025, which can add years to the payback.
Net metering and exports in New Hampshire: Net metering credits ~25% below retail, carried forward indefinitely; program extended through 2040.
Battery: a 13.5-kWh battery at the New Hampshire average of $1,089/kWh adds $14,702 and shifts about 2,991 kWh a year from low-paid exports to your own use; payback becomes 16.1 years.
EnergySage's New Hampshire page lists a 9.9-year payback. Its method is not fully published; ours uses EIA's Jan–Aug 2026 price, 40% self-use and the state's export credit, 3%/yr rate growth and 0.5%/yr panel aging, with no federal credit.
The full method, material data and tips are on the main solar payback calculator page.