Peak sun hours/day and estimated payback (simple payback, 6 kW system at 2.75$/W installed, 80% system efficiency).
| State | Sun Hours | 6 kW Payback |
|---|---|---|
| Alaska | 3.0 | 11.5 years |
| Alabama | 4.6 | 11.8 years |
| Arkansas | 4.7 | 14.1 years |
| Arizona | 6.5 | 9.4 years |
| California | 5.8 | 4.6 years |
| Colorado | 5.5 | 10.3 years |
| Connecticut | 4.2 | 7.0 years |
| District of Columbia | 4.5 | 8.2 years |
| Delaware | 4.5 | 11.1 years |
| Florida | 5.4 | 11.3 years |
| Georgia | 5.0 | 12.2 years |
| Hawaii | 5.6 | 3.6 years |
| Iowa | 4.5 | 15.1 years |
| Idaho | 4.6 | 16.1 years |
| Illinois | 4.5 | 10.2 years |
| Indiana | 4.4 | 11.9 years |
| Kansas | 5.6 | 10.7 years |
| Kentucky | 4.4 | 14.2 years |
| Louisiana | 4.9 | 13.3 years |
| Massachusetts | 4.2 | 7.6 years |
| Maryland | 4.5 | 9.5 years |
| Maine | 4.2 | 7.9 years |
| Michigan | 4.1 | 10.7 years |
| Minnesota | 4.4 | 13.1 years |
| Missouri | 4.7 | 14.3 years |
| Mississippi | 4.8 | 11.7 years |
| Montana | 4.3 | 15.7 years |
| North Carolina | 4.9 | 11.8 years |
| North Dakota | 4.6 | 16.6 years |
| Nebraska | 5.0 | 14.2 years |
| New Hampshire | 4.1 | 8.4 years |
| New Jersey | 4.4 | 9.1 years |
| New Mexico | 6.2 | 10.0 years |
| Nevada | 6.4 | 10.3 years |
| New York | 4.0 | 8.0 years |
| Ohio | 4.1 | 11.8 years |
| Oklahoma | 5.6 | 12.6 years |
| Oregon | 3.7 | 16.1 years |
| Pennsylvania | 4.1 | 10.7 years |
| Rhode Island | 4.3 | 7.7 years |
| South Carolina | 5.0 | 11.0 years |
| South Dakota | 4.8 | 13.5 years |
| Tennessee | 4.5 | 14.0 years |
| Texas | 5.3 | 10.5 years |
| Utah | 5.3 | 13.4 years |
| Virginia | 4.6 | 11.8 years |
| Vermont | 4.0 | 9.6 years |
| Washington | 3.6 | 18.2 years |
| Wisconsin | 4.3 | 11.4 years |
| West Virginia | 4.0 | 14.7 years |
| Wyoming | 5.0 | 12.8 years |