Peak sun hours in Indiana
Indiana averages 4.2 peak sun hours a day across the year, 32nd of the 50 states. At that figure a 400-watt panel produces about 1.29 kWh a day after real-world losses, and covering the 900 kWh average US bill takes about 23 panels. Indianapolis, the state's biggest city, sits at 4.2 hours, close enough to the statewide figure to use either, though elevation and distance from water still move the number street by street.
modest sun: 4.2 of a possible ~6.5 hours
Panel counts for Indiana bills
Computed at Indiana's 4.2 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 | Indiana | System size | US average |
|---|---|---|---|
| 500 kWh/mo | 13 panels | 5.2 kW | 12 panels |
| 750 kWh/mo | 20 panels | 8 kW | 18 panels |
| 900 kWh/mo | 23 panels | 9.2 kW | 22 panels |
| 1,000 kWh/mo | 26 panels | 10.4 kW | 24 panels |
| 1,500 kWh/mo | 39 panels | 15.6 kW | 36 panels |
| 2,000 kWh/mo | 51 panels | 20.4 kW | 48 panels |
What 4.2 hours means in practice
Indiana runs 7% below the national solar average, 32nd of 50 at 4.2 hours. That is workable sun, not bad sun: the 900 kWh bill takes 23 panels here versus 22 nationally, 1 more. Germany built the world's densest solar fleet on worse.
How a Indiana year is shaped
The 4.2-hour figure is an annual average, and no month is average. These are the twelve monthly means for Indiana from NASA's 2001-2020 solar climatology, each as a share of the state's own annual mean, with that share applied to the 4.2-hour planning figure. June and December are marked.
| Month | Share of the annual average | Peak sun hours (est.) |
|---|---|---|
| January | 45% | 1.9 |
| February | 65% | 2.7 |
| March | 91% | 3.8 |
| April | 122% | 5.1 |
| May | 138% | 5.8 |
| June | 157% | 6.6 |
| July | 155% | 6.5 |
| August | 139% | 5.8 |
| September | 114% | 4.8 |
| October | 79% | 3.3 |
| November | 54% | 2.3 |
| December | 38% | 1.6 |
Indiana spans 4.1 to one across the year, June at 157% of the annual average and December at 38%, which is 6.6 hours a day against 1.6. The four best months carry 49% of the light. Wide enough to matter to a battery, routine for anything grid-tied.
Half the Indiana calendar sits above the annual average and half below: April through September are the six months that beat it, carrying 69% of the year's light. April is already worth about 5.1 hours a day, so the productive half of the year starts earlier than most people expect.
Indiana's average home used 901 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 23 panels across the year and 60 to be carried by December sun alone, a factor of 2.6.
Indiana is more uniform than most. The 11 grid cells sampled across the state span 8%, sunniest in the southwest and dimmest in the north, which scales to about 4.4 hours against 4.0. Enough to notice on a production estimate, not enough to change which system you buy. Indianapolis sits inside that band, not at the edge of it.
What that sun is worth on a Indiana bill
| EIA, 2024 residential averages | Indiana | United States |
|---|---|---|
| Average home's monthly use | 901 kWh | 863 kWh |
| Price per kilowatt-hour | 14.77¢ | 16.48¢ |
| Average monthly bill | $133.06 | $142.26 |
| One 400W panel, a year's output | 472 kWh | 506 kWh |
| What that output displaces | $70 | $83 |
Cheap power cuts the other way. Indiana residential electricity averaged 14.77¢ a kilowatt-hour in 2024, 10% under the national 16.48¢ and 25th 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.
Indiana ranks 32nd of fifty for sun but 36th for what a panel is worth, 4 places lower, because the power it displaces is cheap. Rhode Island gets less sun (4.1 hours to Indiana's 4.2) and pays 28.65¢ against 14.77¢, so one panel is worth about $62 less a year in Indiana 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; 14.77¢ is every Indiana 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 Indiana?
About 23 400-watt panels (9.2 kW) for the 900 kWh a month an average US home uses, at Indiana's 4.2 peak sun hours. For the average Indiana home specifically, which EIA measured at 901 kWh a month in 2024, it is 23. Your own bill is the variable that matters, and the calculator takes any figure.
Is 4.2 peak sun hours good for solar?
It is below the 4.5-hour national average but far from disqualifying. Panel counts run about 7% 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 Indiana?
About $70. One 400-watt panel at Indiana's 4.2 peak sun hours makes roughly 472 kWh a year after the 0.77 derate, and Indiana residential electricity averaged 14.77¢ a kilowatt-hour in 2024 (EIA), which puts Indiana 36th of the 50 states on this measure against 32nd 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 Indiana?
Yes, by a factor of 4.1 here. NASA's 2001-2020 climatology puts Indiana's June at 157% of the annual average and December at 38%, so the 4.2-hour figure on this page is the midpoint of a curve running from roughly 6.6 hours a day down to 1.6. Grid-tied homes bank the summer surplus as credit; off-grid designs have to size for the trough, and in Indiana that means 60 panels for an average local bill instead of 23.