Peak sun hours in Colorado
Colorado averages 5.5 peak sun hours a day across the year, 6th 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. Denver, the state's biggest city, sits at 5.5 hours, close enough to the statewide figure to use either, though elevation and distance from water still move the number street by street.
strong sun: 5.5 of a possible ~6.5 hours
Panel counts for Colorado bills
Computed at Colorado'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 | Colorado | 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
Colorado sits in the strong tier of American sun, 6th 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 Colorado year is shaped
The 5.5-hour figure is an annual average, and no month is average. These are the twelve monthly means for Colorado 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 | 55% | 3.0 |
| February | 73% | 4.0 |
| March | 100% | 5.5 |
| April | 120% | 6.6 |
| May | 136% | 7.5 |
| June | 152% | 8.3 |
| July | 140% | 7.7 |
| August | 126% | 6.9 |
| September | 109% | 6.0 |
| October | 82% | 4.5 |
| November | 60% | 3.3 |
| December | 48% | 2.6 |
The gap between Colorado's best month and its worst is 3.2 to one: June at 152% of the annual average, December at 48%, or about 8.3 hours a day against 2.6. Four months carry 46% of the year's light. Note the July step down to 140%. That is the summer storm cycle, not a weaker sun. A grid-tied system rides that out on net metering without anyone noticing.
Half the Colorado 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 6.6 hours a day, so the productive half of the year starts earlier than most people expect.
Colorado homes are light users by national standards, 674 kWh a month on EIA's 2024 average against 863 nationally, 22% below. That is only 14 panels at the annual figure, which is why modest arrays go a long way here. Carrying the same house through December on its own would take 28, 2.0 times more.
The state average also hides a real geographic split. Sampling 20 grid cells across Colorado, the southwest comes out 15% sunnier than the north: call it 5.9 hours against 5.1 once it is scaled to the 5.5-hour statewide figure. That is larger than the gap between many neighbouring states in the ranking.
What that sun is worth on a Colorado bill
| EIA, 2024 residential averages | Colorado | United States |
|---|---|---|
| Average home's monthly use | 674 kWh | 863 kWh |
| Price per kilowatt-hour | 14.92¢ | 16.48¢ |
| Average monthly bill | $100.57 | $142.26 |
| One 400W panel, a year's output | 618 kWh | 506 kWh |
| What that output displaces | $92 | $83 |
Cheap power cuts the other way. Colorado residential electricity averaged 14.92¢ a kilowatt-hour in 2024, 9% under the national 16.48¢ and 27th cheapest in the country, so the same panel that offsets $83 a year at national rates offsets about $92 here. Nothing is wrong with the sun. There is just less money in each kilowatt-hour it makes.
Colorado ranks 6th of fifty for sun but 13th for what a panel is worth, 7 places lower, because the power it displaces is cheap. Hawaii gets more sun (5.6 hours to Colorado's 5.5) and pays 42.86¢ against 14.92¢, so one panel is worth about $178 less a year in Colorado 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; 14.92¢ is every Colorado 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 Colorado?
About 18 400-watt panels (7.2 kW) for the 900 kWh a month an average US home uses, at Colorado's 5.5 peak sun hours. For the average Colorado home specifically, which EIA measured at 674 kWh a month in 2024, it is 14. 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. Colorado ranks 6th 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 Colorado?
About $92. One 400-watt panel at Colorado's 5.5 peak sun hours makes roughly 618 kWh a year after the 0.77 derate, and Colorado residential electricity averaged 14.92¢ a kilowatt-hour in 2024 (EIA), which puts Colorado 13th of the 50 states on this measure against 6th 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 Colorado?
Yes, by a factor of 3.2 here. NASA's 2001-2020 climatology puts Colorado's June at 152% of the annual average and December at 48%, so the 5.5-hour figure on this page is the midpoint of a curve running from roughly 8.3 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 Colorado that means 28 panels for an average local bill instead of 14.