Solar · New Hampshire
How many solar panels do I need in New Hampshire?
For the average New Hampshire home, which uses 619 kWh a month (EIA, 2024), about 14 × 400 W solar panels (5.21 kW) facing south at the best tilt. One kW of panels in New Hampshire makes about 1,426 kWh a year, 4.5 kWh a day in July and 2.7 in December, the 39th sunniest of 51.
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Solar output by month in New Hampshire
Output falls to 60% of the July level in December. Grid-tied homes are sized on the year; anything off-grid has to be sized for December.
| Month | kWh per kW | Per day | 200 W panel, Wh/day into a battery |
|---|---|---|---|
| January | 99 | 3.21 | 546 |
| February | 112 | 4.00 | 679 |
| March | 135 | 4.35 | 739 |
| April | 130 | 4.34 | 738 |
| May | 134 | 4.32 | 735 |
| June | 128 | 4.27 | 726 |
| July | 138 | 4.46 | 758 |
| August | 137 | 4.43 | 753 |
| September | 127 | 4.24 | 721 |
| October | 108 | 3.49 | 593 |
| November | 93 | 3.11 | 528 |
| December | 83 | 2.68 | 456 |
Charging a power station in New Hampshire
A 200 W panel propped up facing south refills a 1,000 Wh power station in about 1.3 days in July and 2.2 days in December. To refill it in one day you’d need about 270 W of panels in July and 440 W in December. Check your station and panel →
A balcony or plug-in panel in New Hampshire
A 400 W panel hanging upright on a south-facing railing makes about 399 kWh a year, worth about $110 at New Hampshire’s average rate (27.64¢/kWh, August 2026), if you use the power as it’s made. Shade and the rules where you live matter more than anything here. Try your kit →
The rules in New Hampshire: New Hampshire law (SB 540, Chapter 262, 2026; signed July 2, 2026, takes effect January 1, 2027) on plug-in solar says: “Each metered customer shall be allowed a maximum of one plug-in solar generation system with a maximum inverter output of 1,200 watts AC.” … “Obtain electric distribution utility approval before installing or using the system”. Check with your utility before connecting. Official source: New Hampshire General Court, SB 540 chaptered text; checked November 5, 2026. Every state we track →
Across New Hampshire
New Hampshire’s figure is the population-weighted average of Manchester, Nashua and Concord, its three largest cities; across them, a kW makes 1,403 to 1,431 kWh a year.
| City | Population (2024) | kWh per kW a year |
|---|---|---|
| Manchester | 116,386 | 1,430 |
| Nashua | 91,851 | 1,431 |
| Concord | 44,674 | 1,403 |
Cross-check: an estimate from NASA POWER sunshine came out at 1,260 kWh per kW, 13% below the Global Solar Atlas figure. That’s more than our 12% review threshold, so we checked it by hand: both sources agree on the sunshine itself; the gap comes from the cross-check’s simpler tilt model and its fixed losses, which understate output in cool climates. We use the Global Solar Atlas figure.
Electricity rates and appliance costs in New Hampshire →
FAQ
How many solar panels do I need in New Hampshire?
For the average New Hampshire home, which uses 619 kWh a month (EIA, 2024), about 14 × 400 W solar panels (5.21 kW) facing south at the best tilt. One kW of panels in New Hampshire makes about 1,426 kWh a year, 4.5 kWh a day in July and 2.7 in December, the 39th sunniest of 51.
How much does a solar panel produce in New Hampshire?
A 400 W panel facing south at the best tilt makes about 570 kWh a year in New Hampshire: about 55 kWh in July and 33 kWh in December (Global Solar Atlas).
How long does a 200 W solar panel take to charge a 1,000 Wh power station in New Hampshire?
About 1.3 days in July and 2.2 days in December, propped up facing south, at 85% charging efficiency. Lying flat, about 4.3 days in December.
How many solar panels for the U.S. average home in New Hampshire?
The U.S. average home uses 863 kWh a month (EIA, 2024). In New Hampshire that takes about 7.26 kW: 19 × 400 W panels.
Is there still a federal solar tax credit?
Not under the residential credit for systems installed after 2025: the IRS says the section 25D credit will not be allowed for any expenditures made after December 31, 2025, and an expenditure counts as made when installation is completed.
Sources and assumptions
- Solar output (kWh per kW of panels, by month): Global Solar Atlas 2.0, long-term averages to 2025 (data version 2.2.68, updated 2026-04-01), for crystalline-silicon panels facing south at the best fixed tilt, after typical system losses. Data obtained from the “Global Solar Atlas 2.0, a free, web-based application is developed and operated by the company Solargis s.r.o. on behalf of the World Bank Group, utilizing Solargis data, with funding provided by the Energy Sector Management Assistance Program (ESMAP). For additional information: https://globalsolaratlas.info” Licensed CC BY 4.0; we rounded and combined it as described here. Not affiliated with or endorsed by Solargis or the World Bank Group.
- State figure: population-weighted average of the state’s three largest cities (U.S. Census Bureau Vintage 2024 population estimates; coordinates from the 2020 Census Gazetteer). Hawaii and DC use one city.
- Cross-check: NASA POWER sunshine climatology (2001–2025), tilted with a standard isotropic-sky model × 0.80. States more than 12% apart were reviewed by hand; the gaps are explained on our methodology page.
- Home use: EIA Table 5A, 2024 average monthly residential kWh by state. Rates: EIA Electric Power Monthly, August 2026.
- Tax credit: IRS FAQ on the One, Big, Beautiful Bill (FS-2025-05, Aug. 21, 2025).
- Assumptions: 85% charging efficiency into a battery, 85% from battery to appliance, panel counts rounded up, off-grid sizing for the worst month.