Peak sun hours in Ohio
Ohio averages 3.9 peak sun hours a day across the year, 44th of the 50 states. At that figure a 400-watt panel produces about 1.20 kWh a day after real-world losses, and covering the 900 kWh average US bill takes about 25 panels. Columbus, the state's biggest city, runs slightly ahead of the statewide figure at 4 hours; treat 3.9 as the midpoint of a real spread rather than a local reading.
modest sun: 3.9 of a possible ~6.5 hours
Panel counts for Ohio bills
Computed at Ohio's 3.9 hours with 400W panels and the 0.77 derate; the US-average column shows what the same bill takes at 4.5 hours, so you can see what your state's sun is worth in hardware.
| Monthly usage | Ohio | System size | US average |
|---|---|---|---|
| 500 kWh/mo | 14 panels | 5.6 kW | 12 panels |
| 750 kWh/mo | 21 panels | 8.4 kW | 18 panels |
| 900 kWh/mo | 25 panels | 10 kW | 22 panels |
| 1,000 kWh/mo | 28 panels | 11.2 kW | 24 panels |
| 1,500 kWh/mo | 42 panels | 16.8 kW | 36 panels |
| 2,000 kWh/mo | 55 panels | 22 kW | 48 panels |
What 3.9 hours means in practice
Ohio runs 13% below the national solar average, 44th of 50 at 3.9 hours. That is workable sun, not bad sun: the 900 kWh bill takes 25 panels here versus 22 nationally, 3 more. Germany built the world's densest solar fleet on worse.
How a Ohio year is shaped
The 3.9-hour figure is an annual average, and no month is average. These are the twelve monthly means for Ohio from NASA's 2001-2020 solar climatology, each as a share of the state's own annual mean, with that share applied to the 3.9-hour planning figure. June and December are marked.
| Month | Share of the annual average | Peak sun hours (est.) |
|---|---|---|
| January | 43% | 1.7 |
| February | 64% | 2.5 |
| March | 90% | 3.5 |
| April | 123% | 4.8 |
| May | 142% | 5.5 |
| June | 158% | 6.2 |
| July | 157% | 6.1 |
| August | 141% | 5.5 |
| September | 115% | 4.5 |
| October | 78% | 3.0 |
| November | 53% | 2.1 |
| December | 36% | 1.4 |
Ohio spans 4.4 to one across the year, June at 158% of the annual average and December at 36%, which is 6.2 hours a day against 1.4. The four best months carry 50% of the light. Wide enough to matter to a battery, routine for anything grid-tied.
Half the Ohio calendar sits above the annual average and half below: April through September are the six months that beat it, carrying 70% of the year's light. April is already worth about 4.8 hours a day, so the productive half of the year starts earlier than most people expect.
Ohio's average home used 846 kWh a month in 2024 by EIA's count, within a few percent of the national 863, so the national panel counts on this page transfer here better than they do in most states. That average bill needs 24 panels across the year and 64 to be carried by December sun alone, a factor of 2.7.
Ohio is more uniform than most. The 11 grid cells sampled across the state span 10%, sunniest in the south and dimmest in the northeast, which scales to about 4.1 hours against 3.7. Enough to notice on a production estimate, not enough to change which system you buy. Columbus sits inside that band, not at the edge of it.
What that sun is worth on a Ohio bill
| EIA, 2024 residential averages | Ohio | United States |
|---|---|---|
| Average home's monthly use | 846 kWh | 863 kWh |
| Price per kilowatt-hour | 15.99¢ | 16.48¢ |
| Average monthly bill | $135.16 | $142.26 |
| One 400W panel, a year's output | 438 kWh | 506 kWh |
| What that output displaces | $70 | $83 |
At 15.99¢ a kilowatt-hour Ohio sits 3% below the national 16.48¢, 17th of the fifty states on price. One 400-watt panel offsets roughly $70 of Ohio power a year. Mid-table on rates means the project lives or dies on the quote and the net-metering terms rather than on either the sun or the tariff.
Rank Ohio by what a panel earns rather than by sunlight and it moves up 10 places, from 44th to 34th. Rates do that. Rhode Island gets more sun (4.1 hours to Ohio's 3.9) and pays 28.65¢ against 15.99¢, so one panel is worth about $62 less a year in Ohio than in Rhode Island.
Two warnings on those dollar figures. They are displaced electricity and nothing else: no install cost, no incentive, no financing, and no assumption about how your utility settles a surplus, which is the single biggest unknown in the sum. And a state average hides the utility you are actually on; 15.99¢ is every Ohio residential customer averaged together, and neighbouring territories can differ by more than the gap between two states in the ranking.
Getting a number for your address
For a location-exact figure, run your address through NREL's free PVWatts; it uses measured weather for your grid cell and will also model roof tilt and direction, which statewide numbers cannot. Then compare its annual kWh against a quote's promise before you sign anything.
Questions people ask
How many solar panels do I need in Ohio?
About 25 400-watt panels (10 kW) for the 900 kWh a month an average US home uses, at Ohio's 3.9 peak sun hours. For the average Ohio home specifically, which EIA measured at 846 kWh a month in 2024, it is 24. Your own bill is the variable that matters, and the calculator takes any figure.
Is 3.9 peak sun hours good for solar?
It is below the 4.5-hour national average but far from disqualifying. Panel counts run about 15% higher here for the same bill, and the December trough measured above deserves respect in any off-grid plan. Grid-tied systems ride through it on net metering.
How much is one solar panel worth a year in Ohio?
About $70. One 400-watt panel at Ohio's 3.9 peak sun hours makes roughly 438 kWh a year after the 0.77 derate, and Ohio residential electricity averaged 15.99¢ a kilowatt-hour in 2024 (EIA), which puts Ohio 34th of the 50 states on this measure against 44th on sunlight alone. That figure is displaced electricity only. It says nothing about install cost, incentives, or how your utility settles a surplus.
Do peak sun hours change with the seasons in Ohio?
Yes, by a factor of 4.4 here. NASA's 2001-2020 climatology puts Ohio's June at 158% of the annual average and December at 36%, so the 3.9-hour figure on this page is the midpoint of a curve running from roughly 6.2 hours a day down to 1.4. Grid-tied homes bank the summer surplus as credit; off-grid designs have to size for the trough, and in Ohio that means 64 panels for an average local bill instead of 24.