Peak sun hours in Utah
Utah averages 5.5 peak sun hours a day across the year, 7th of the 50 states. At that figure a 400-watt panel produces about 1.69 kWh a day after real-world losses, and covering the 900 kWh average US bill takes about 18 panels. Salt Lake City, the state's biggest city, sits a little under the statewide figure at 5.3 hours, so 5.5 is the midpoint of a spread that leans away from the largest population centre.
strong sun: 5.5 of a possible ~6.5 hours
Panel counts for Utah bills
Computed at Utah's 5.5 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 | Utah | System size | US average |
|---|---|---|---|
| 500 kWh/mo | 10 panels | 4 kW | 12 panels |
| 750 kWh/mo | 15 panels | 6 kW | 18 panels |
| 900 kWh/mo | 18 panels | 7.2 kW | 22 panels |
| 1,000 kWh/mo | 20 panels | 8 kW | 24 panels |
| 1,500 kWh/mo | 30 panels | 12 kW | 36 panels |
| 2,000 kWh/mo | 39 panels | 15.6 kW | 48 panels |
What 5.5 hours means in practice
Utah sits in the strong tier of American sun, 7th of 50 at 5.5 hours, 22% above the national average. In panel terms the 900 kWh average bill needs 18 panels here instead of the US-average 22. Systems this far into the Sun Belt usually pencil on production alone; the variables that actually kill quotes here are shade and roof direction, not the resource.
How a Utah year is shaped
The 5.5-hour figure is an annual average, and no month is average. These are the twelve monthly means for Utah from NASA's 2001-2020 solar climatology, each as a share of the state's own annual mean, with that share applied to the 5.5-hour planning figure. June and December are marked.
| Month | Share of the annual average | Peak sun hours (est.) |
|---|---|---|
| January | 50% | 2.8 |
| February | 68% | 3.8 |
| March | 96% | 5.3 |
| April | 121% | 6.7 |
| May | 140% | 7.7 |
| June | 158% | 8.7 |
| July | 144% | 7.9 |
| August | 129% | 7.1 |
| September | 111% | 6.1 |
| October | 82% | 4.5 |
| November | 57% | 3.1 |
| December | 43% | 2.4 |
Utah's curve tops out in June at 158% of the annual average and bottoms in December at 43%, a 3.7-to-one spread with 48% of the year's light landing in four months. In hours: 8.7 a day at the peak, about 2.4 in December. July gives some of it back, running 144% against June's 158%, which is cloud cover arriving with the heat rather than the sun weakening.
Half the Utah calendar sits above the annual average and half below: April through September are the six months that beat it, carrying 67% of the year's light. April is already worth about 6.7 hours a day, so the productive half of the year starts earlier than most people expect.
Worth pinning to a real bill: EIA's 2024 average for a Utah household was 774 kWh a month, 10% under the national figure, which is 16 panels at Utah's annual sun. Sized instead for December it takes 36 panels, 2.3 times as many. The gap between those two numbers is what a grid connection is worth.
Utah is one of the states where a statewide number does the most damage: it has the 7th widest internal spread of the fifty. Across the 20 grid cells sampled here the southeast runs 23% sunnier than the northwest. Held against the 5.5-hour statewide figure that is roughly 6.1 hours at one end and 4.9 at the other, which is the difference between two quite different quotes. Nobody should size a Utah roof off the state average without checking which end of the state it sits on.
What that sun is worth on a Utah bill
| EIA, 2024 residential averages | Utah | United States |
|---|---|---|
| Average home's monthly use | 774 kWh | 863 kWh |
| Price per kilowatt-hour | 12.22¢ | 16.48¢ |
| Average monthly bill | $94.57 | $142.26 |
| One 400W panel, a year's output | 618 kWh | 506 kWh |
| What that output displaces | $76 | $83 |
Cheap power cuts the other way. Utah residential electricity averaged 12.22¢ a kilowatt-hour in 2024, 26% under the national 16.48¢ and 6th cheapest in the country, so the same panel that offsets $83 a year at national rates offsets about $76 here. Nothing is wrong with the sun. There is just less money in each kilowatt-hour it makes.
Here the sun ranking flatters Utah. 7th of fifty for sunlight, but only 27th for what a panel earns in a year, a drop of 20 places, and the reason is entirely the price of the electricity being replaced. Hawaii gets more sun (5.6 hours to Utah's 5.5) and pays 42.86¢ against 12.22¢, so one panel is worth about $194 less a year in Utah than in Hawaii.
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; 12.22¢ is every Utah 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 Utah?
About 18 400-watt panels (7.2 kW) for the 900 kWh a month an average US home uses, at Utah's 5.5 peak sun hours. For the average Utah home specifically, which EIA measured at 774 kWh a month in 2024, it is 16. Your own bill is the variable that matters, and the calculator takes any figure.
Is 5.5 peak sun hours good for solar?
Yes, comfortably. Utah ranks 7th of the 50 states, 22% above the national average, which means fewer panels per kWh of bill than almost anywhere else in the country.
How much is one solar panel worth a year in Utah?
About $76. One 400-watt panel at Utah's 5.5 peak sun hours makes roughly 618 kWh a year after the 0.77 derate, and Utah residential electricity averaged 12.22¢ a kilowatt-hour in 2024 (EIA), which puts Utah 27th of the 50 states on this measure against 7th 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 Utah?
Yes, by a factor of 3.7 here. NASA's 2001-2020 climatology puts Utah's June at 158% of the annual average and December at 43%, so the 5.5-hour figure on this page is the midpoint of a curve running from roughly 8.7 hours a day down to 2.4. Grid-tied homes bank the summer surplus as credit; off-grid designs have to size for the trough, and in Utah that means 36 panels for an average local bill instead of 16.