Peak sun hours in Oklahoma
Oklahoma averages 5.1 peak sun hours a day across the year, 11th of the 50 states. At that figure a 400-watt panel produces about 1.57 kWh a day after real-world losses, and covering the 900 kWh average US bill takes about 19 panels. Oklahoma City, the state's biggest city, beats the statewide figure by 0.3 hours at 5.4, which means the rest of Oklahoma pulls the 5.1 average down and a quote written to the state number understates a Oklahoma City roof.
solid mid-pack sun: 5.1 of a possible ~6.5 hours
Panel counts for Oklahoma bills
Computed at Oklahoma's 5.1 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 | Oklahoma | System size | US average |
|---|---|---|---|
| 500 kWh/mo | 11 panels | 4.4 kW | 12 panels |
| 750 kWh/mo | 16 panels | 6.4 kW | 18 panels |
| 900 kWh/mo | 19 panels | 7.6 kW | 22 panels |
| 1,000 kWh/mo | 21 panels | 8.4 kW | 24 panels |
| 1,500 kWh/mo | 32 panels | 12.8 kW | 36 panels |
| 2,000 kWh/mo | 42 panels | 16.8 kW | 48 panels |
What 5.1 hours means in practice
Oklahoma is mid-pack American sun: 11th of 50 at 5.1 peak sun hours, within 13% of the national average. The 900 kWh average bill lands at 19 panels against 22 nationally. At this tier the resource neither makes nor breaks the project, which is what the rate and the seasonal spread below are for.
How a Oklahoma year is shaped
The 5.1-hour figure is an annual average, and no month is average. These are the twelve monthly means for Oklahoma from NASA's 2001-2020 solar climatology, each as a share of the state's own annual mean, with that share applied to the 5.1-hour planning figure. June and December are marked.
| Month | Share of the annual average | Peak sun hours (est.) |
|---|---|---|
| January | 59% | 3.0 |
| February | 72% | 3.7 |
| March | 95% | 4.9 |
| April | 118% | 6.0 |
| May | 129% | 6.6 |
| June | 146% | 7.5 |
| July | 144% | 7.4 |
| August | 130% | 6.6 |
| September | 109% | 5.5 |
| October | 83% | 4.2 |
| November | 63% | 3.2 |
| December | 51% | 2.6 |
The gap between Oklahoma's best month and its worst is 2.9 to one: June at 146% of the annual average, December at 51%, or about 7.5 hours a day against 2.6. Four months carry 46% of the year's light. A grid-tied system rides that out on net metering without anyone noticing.
Half the Oklahoma calendar sits above the annual average and half below: April through September are the six months that beat it, carrying 65% of the year's light. April is already worth about 6.0 hours a day, so the productive half of the year starts earlier than most people expect.
Set that against what Oklahoma homes actually draw. EIA measured 1,079 kWh a month for the average household here in 2024, 25% above the US figure, which is 23 panels at the annual average sun. Hold the same house to a December and the count goes to 45, 2.0 times higher. Net metering is what makes the first number the one that matters.
Oklahoma is one of the states where a statewide number does the most damage: it has the 10th widest internal spread of the fifty. Across the 20 grid cells sampled here the northwest runs 20% sunnier than the southeast. Held against the 5.1-hour statewide figure that is roughly 5.6 hours at one end and 4.6 at the other, which is the difference between two quite different quotes. Nobody should size a Oklahoma roof off the state average without checking which end of the state it sits on.
What that sun is worth on a Oklahoma bill
| EIA, 2024 residential averages | Oklahoma | United States |
|---|---|---|
| Average home's monthly use | 1,079 kWh | 863 kWh |
| Price per kilowatt-hour | 12.24¢ | 16.48¢ |
| Average monthly bill | $132.05 | $142.26 |
| One 400W panel, a year's output | 573 kWh | 506 kWh |
| What that output displaces | $70 | $83 |
Cheap power cuts the other way. Oklahoma residential electricity averaged 12.24¢ a kilowatt-hour in 2024, 26% under the national 16.48¢ and 7th cheapest in the country, so the same panel that offsets $83 a year at national rates offsets about $70 here. Nothing is wrong with the sun. There is just less money in each kilowatt-hour it makes.
Here the sun ranking flatters Oklahoma. 11th of fifty for sunlight, but only 33rd for what a panel earns in a year, a drop of 22 places, and the reason is entirely the price of the electricity being replaced. Kansas gets more sun (5.2 hours to Oklahoma's 5.1) and pays 14.15¢ against 12.24¢, so one panel is worth about $13 less a year in Oklahoma than in Kansas.
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; 12.24¢ is every Oklahoma 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 Oklahoma?
About 19 400-watt panels (7.6 kW) for the 900 kWh a month an average US home uses, at Oklahoma's 5.1 peak sun hours. For the average Oklahoma home specifically, which EIA measured at 1,079 kWh a month in 2024, it is 23. Your own bill is the variable that matters, and the calculator takes any figure.
Is 5.1 peak sun hours good for solar?
It is solidly workable. Oklahoma sits near the national average of 4.5 hours, so panel counts here match the US-typical figures, and project economics turn on your utility's rates and net-metering terms rather than on the sun.
How much is one solar panel worth a year in Oklahoma?
About $70. One 400-watt panel at Oklahoma's 5.1 peak sun hours makes roughly 573 kWh a year after the 0.77 derate, and Oklahoma residential electricity averaged 12.24¢ a kilowatt-hour in 2024 (EIA), which puts Oklahoma 33rd of the 50 states on this measure against 11th 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 Oklahoma?
Yes, by a factor of 2.9 here. NASA's 2001-2020 climatology puts Oklahoma's June at 146% of the annual average and December at 51%, so the 5.1-hour figure on this page is the midpoint of a curve running from roughly 7.5 hours a day down to 2.6. Grid-tied homes bank the summer surplus as credit; off-grid designs have to size for the trough, and in Oklahoma that means 45 panels for an average local bill instead of 23.