Solar panels cost thousands up front and save money every month for 25 years or more. Whether they're worth it comes down to one number: how many years the savings take to cover the cost. We worked that out for every US state, Washington DC and seven UK regions, using 2026 electricity prices, typical installed costs and modelled sunshine for each place.
Want your own figure? The solar panel calculator does the same sums for your bill, roof and quote.
The short answer
- US: payback runs from 3.3 years in Hawaii to 14.6 in Washington state. The middle state takes about 10 years, and a system typically saves 2 to 6 times its cost over 25 years.
- UK: a typical 3 kW system pays back in about 8.5 years in southern England and Wales and about 10 years in northern England and Scotland.
- What matters most: your electricity price, then how much of the solar you use yourself (or how well exports are paid), then sunshine and installed cost.
How we worked it out
- US home: uses 860 kWh a month (10,320 a year). The system is sized to cover all of it, in 430 W panels.
- UK home: uses 2,700 kWh a year, Ofgem's figure for a typical household.
- Sunshine: the yearly output of 1 kW of panels, modelled with the European Commission's PVGIS for each state's largest city and one city per UK region (south-facing, 30° tilt in the US and 35° in the UK, 14% system losses, 2005–2023 weather).
- Electricity prices: US state averages from the Energy Information Administration (January–July 2026). UK: the Ofgem price cap for October–December 2026, 26.32p per kWh.
- Installed cost: $2.60 a watt in the US (EnergySage marketplace average, before incentives). £1,820 a kW in the UK (DESNZ figures for domestic retrofits, April 2025–March 2026).
- Incentives: none assumed (see below).
- Over time: electricity prices rise 2% a year, and panels lose 0.5% of their output a year.
- US exports: every kWh is worth the full retail price, as with full net metering.
- UK exports: half the output is used at home; the other half is exported at 15p under the Smart Export Guarantee.
Solar payback by US state (2026)
Sorted from fastest to slowest payback. "Net gain" is 25 years of savings minus the cost.
| State | Price per kWh | kWh per kW a year | System | Cost | Year-1 savings | Payback | 25-year net gain |
|---|---|---|---|---|---|---|---|
| Hawaii | 46.28¢ | 1,698 | 6.5 kW | $16,770 | $5,069 | 3.3 yrs | $135,417 |
| California | 33.25¢ | 1,700 | 6.5 kW | $16,770 | $3,646 | 4.5 yrs | $92,698 |
| Maine | 29.99¢ | 1,368 | 7.7 kW | $20,124 | $3,175 | 6.1 yrs | $75,219 |
| Massachusetts | 30.14¢ | 1,323 | 8.2 kW | $21,242 | $3,258 | 6.3 yrs | $76,574 |
| New York | 29.38¢ | 1,341 | 7.7 kW | $20,124 | $3,049 | 6.3 yrs | $71,436 |
| Connecticut | 27.97¢ | 1,396 | 7.7 kW | $20,124 | $3,022 | 6.4 yrs | $70,617 |
| Rhode Island | 29.22¢ | 1,312 | 8.2 kW | $21,242 | $3,132 | 6.5 yrs | $72,800 |
| New Hampshire | 26.79¢ | 1,308 | 8.2 kW | $21,242 | $2,863 | 7.1 yrs | $64,716 |
| District of Columbia | 24.66¢ | 1,352 | 7.7 kW | $20,124 | $2,581 | 7.4 yrs | $57,357 |
| New Jersey | 23.98¢ | 1,337 | 7.7 kW | $20,124 | $2,482 | 7.7 yrs | $54,385 |
| Vermont | 23.95¢ | 1,232 | 8.6 kW | $22,360 | $2,538 | 8.3 yrs | $53,831 |
| Michigan | 21.53¢ | 1,358 | 7.7 kW | $20,124 | $2,263 | 8.4 yrs | $47,823 |
| Colorado | 16.72¢ | 1,724 | 6.0 kW | $15,652 | $1,735 | 8.5 yrs | $36,450 |
| Maryland | 21.30¢ | 1,341 | 7.7 kW | $20,124 | $2,211 | 8.6 yrs | $46,256 |
| Pennsylvania | 21.04¢ | 1,349 | 7.7 kW | $20,124 | $2,197 | 8.6 yrs | $45,837 |
| New Mexico | 15.08¢ | 1,826 | 6.0 kW | $15,652 | $1,658 | 8.9 yrs | $34,120 |
| Arizona | 15.44¢ | 1,739 | 6.0 kW | $15,652 | $1,616 | 9.1 yrs | $32,880 |
| Wisconsin | 19.00¢ | 1,380 | 7.7 kW | $20,124 | $2,029 | 9.3 yrs | $40,810 |
| Alaska | 27.09¢ | 934 | 11.2 kW | $29,068 | $2,829 | 9.6 yrs | $55,866 |
| Illinois | 19.22¢ | 1,297 | 8.2 kW | $21,242 | $2,037 | 9.8 yrs | $39,909 |
| Ohio | 18.70¢ | 1,318 | 8.2 kW | $21,242 | $2,014 | 9.9 yrs | $39,218 |
| Virginia | 16.83¢ | 1,467 | 7.3 kW | $19,006 | $1,805 | 9.9 yrs | $35,184 |
| Delaware | 17.86¢ | 1,360 | 7.7 kW | $20,124 | $1,880 | 10 yrs | $36,324 |
| Nevada | 13.53¢ | 1,798 | 6.0 kW | $15,652 | $1,464 | 10 yrs | $28,319 |
| Wyoming | 13.95¢ | 1,738 | 6.0 kW | $15,652 | $1,460 | 10 yrs | $28,171 |
| Kansas | 15.21¢ | 1,550 | 6.9 kW | $17,888 | $1,622 | 10.3 yrs | $30,813 |
| South Carolina | 15.93¢ | 1,467 | 7.3 kW | $19,006 | $1,708 | 10.4 yrs | $32,286 |
| Alabama | 16.54¢ | 1,373 | 7.7 kW | $20,124 | $1,758 | 10.6 yrs | $32,652 |
| Indiana | 17.04¢ | 1,334 | 7.7 kW | $20,124 | $1,759 | 10.6 yrs | $32,703 |
| Utah | 13.16¢ | 1,718 | 6.0 kW | $15,652 | $1,361 | 10.7 yrs | $25,214 |
| Minnesota | 16.25¢ | 1,363 | 7.7 kW | $20,124 | $1,714 | 10.9 yrs | $31,349 |
| Florida | 15.30¢ | 1,417 | 7.3 kW | $19,006 | $1,585 | 11.1 yrs | $28,578 |
| Montana | 13.95¢ | 1,552 | 6.9 kW | $17,888 | $1,490 | 11.1 yrs | $26,836 |
| Texas | 16.06¢ | 1,348 | 7.7 kW | $20,124 | $1,676 | 11.1 yrs | $30,187 |
| South Dakota | 14.50¢ | 1,479 | 7.3 kW | $19,006 | $1,568 | 11.2 yrs | $28,064 |
| Georgia | 15.40¢ | 1,387 | 7.7 kW | $20,124 | $1,653 | 11.3 yrs | $29,515 |
| Mississippi | 15.19¢ | 1,385 | 7.7 kW | $20,124 | $1,628 | 11.4 yrs | $28,768 |
| Idaho | 12.96¢ | 1,617 | 6.5 kW | $16,770 | $1,352 | 11.5 yrs | $23,815 |
| Oklahoma | 13.58¢ | 1,529 | 6.9 kW | $17,888 | $1,429 | 11.6 yrs | $25,005 |
| North Carolina | 14.94¢ | 1,376 | 7.7 kW | $20,124 | $1,591 | 11.7 yrs | $27,651 |
| Iowa | 14.20¢ | 1,437 | 7.3 kW | $19,006 | $1,492 | 11.8 yrs | $25,781 |
| Missouri | 13.96¢ | 1,430 | 7.3 kW | $19,006 | $1,459 | 12 yrs | $24,809 |
| West Virginia | 15.47¢ | 1,284 | 8.2 kW | $21,242 | $1,623 | 12 yrs | $27,484 |
| Kentucky | 14.27¢ | 1,333 | 8.2 kW | $21,242 | $1,554 | 12.5 yrs | $25,420 |
| Louisiana | 13.35¢ | 1,424 | 7.3 kW | $19,006 | $1,390 | 12.5 yrs | $22,719 |
| Nebraska | 12.90¢ | 1,484 | 7.3 kW | $19,006 | $1,399 | 12.5 yrs | $23,011 |
| Arkansas | 13.61¢ | 1,388 | 7.7 kW | $20,124 | $1,462 | 12.6 yrs | $23,777 |
| Tennessee | 13.87¢ | 1,339 | 7.7 kW | $20,124 | $1,437 | 12.8 yrs | $23,036 |
| Oregon | 15.40¢ | 1,198 | 9.0 kW | $23,478 | $1,666 | 12.9 yrs | $26,543 |
| North Dakota | 12.36¢ | 1,382 | 7.7 kW | $20,124 | $1,322 | 13.8 yrs | $19,573 |
| Washington | 14.40¢ | 1,113 | 9.5 kW | $24,596 | $1,516 | 14.6 yrs | $20,927 |
Two things stand out:
- Price beats sunshine. Arizona and New Mexico get the most sun, but the fastest paybacks are where power is expensive: Hawaii, California and New England. Massachusetts gets about 24% less sunshine than Arizona, yet pays back nearly 3 years sooner, because each kWh saved is worth nearly twice as much.
- The cost is a national average. Prices differ by state and installer, so use your own quote for a real answer.
Solar payback by UK region (2026)
| Region | kWh per kW a year | System | Cost | Year-1 savings | Payback | 25-year net gain |
|---|---|---|---|---|---|---|
| London and South East England (London) | 988 | 3.0 kW | £5,478 | £614 | 8.7 yrs | £11,526 |
| South West England (Exeter) | 1,020 | 3.0 kW | £5,478 | £634 | 8.4 yrs | £12,077 |
| Midlands (Birmingham) | 940 | 3.0 kW | £5,478 | £585 | 9.1 yrs | £10,700 |
| North of England (Manchester) | 861 | 3.4 kW | £6,261 | £612 | 9.9 yrs | £10,675 |
| Wales (Cardiff) | 1,009 | 3.0 kW | £5,478 | £627 | 8.5 yrs | £11,888 |
| Scotland (Glasgow) | 835 | 3.4 kW | £6,261 | £593 | 10.2 yrs | £10,164 |
| Northern Ireland (Belfast) | 893 | 3.4 kW | £6,261 | £635 | 9.5 yrs | £11,304 |
Northern Ireland isn't covered by Ofgem's price cap, so its row uses the GB price for illustration. Check your own tariff.
The south-west gets about a fifth more sunshine than Glasgow. That's why the same home needs a slightly larger system in the north. UK payback is less sensitive to region than to how you use the power: exported electricity earns 15p but saves you 26.32p when used at home. In London, using 80% of the output yourself instead of 50% cuts payback from 8.7 years to 7.4 (before the cost of any battery). If your export tariff paid only 4p, payback would stretch to 11.4 years.
What changes the answer
Every figure above moves with your own situation. Using our Texas example (11.1 years):
- Net billing instead of net metering: if half the output is exported at 5¢ a kWh, payback stretches to 16.8 years. California's NEM 3.0 and a growing number of utilities pay much less for exports than for imports.
- A cheaper quote: at $2.20 a watt instead of $2.60, payback falls to 9.5 years. Getting three quotes is the easiest way to improve the numbers.
- Flat electricity prices: if prices don't rise at all, payback is 12.4 years instead of 11.1.
- Shade and roof direction: an east- or west-facing roof produces roughly 10–20% less than a south-facing one, and shade can cut a whole string of panels. A good installer models this for your roof.
- Financing: a solar loan's interest adds to the cost, and a lease or power-purchase agreement changes the deal entirely. Compare the total you'd pay, not the monthly payment.
Incentives in 2026
US. The 30% federal Residential Clean Energy Credit doesn't apply to systems whose installation is finished after 31 December 2025, according to the IRS. That's why none of the figures above include it. Many states, utilities and cities still offer rebates, tax credits, property-tax exemptions or performance payments. Check your state's energy office and your utility before you buy, and enter any confirmed rebate in the calculator.
UK. Solar panels installed on homes in Great Britain have 0% VAT until 31 March 2027; the DESNZ cost figures already reflect it. The Smart Export Guarantee requires larger suppliers to pay for exported power, but the rate is up to each supplier, so it's worth shopping around.
Is solar worth it for you?
Solar is most likely to be worth it if:
- you pay more than about 20¢ (US) or 25p (UK) per kWh;
- you have an unshaded roof facing roughly south;
- your utility credits exports fairly, or you use a lot of power during the day;
- you plan to stay in the home for at least the payback period.
It's weakest where electricity is cheap, the roof is shaded or due for replacement, or exports earn little.
Run your own numbers in the solar panel calculator. Enter your bill or appliances, your state or region and your installer's quote, and it shows the system size, savings, payback and a year-by-year table. To see which appliances drive your bill first, try the electricity cost calculator.
Figures are estimates for planning, not financial advice. Last reviewed October 2026.