Solar in Iowa: payback, sun by city and utility-scale capacity
Across 5 Iowa cities, yearly output runs from 1,324 kWh per kW in Waterloo to 1,403 in Sioux City. Jul is the best month at 157 kWh per kW and Dec the worst at 63. Iowa pays back in 15.9 years at $3.00 a watt (rank 38 of 51), 2.4 years longer than the middle state. 1,373 kWh per kW (rank 25) at 13.72 ¢ (rank 36 from the top): sunshine drives it. Utility-scale solar in Iowa: 701 MW in 37 plants, 1.7% of 2025 generation; 776 MW more under construction or planned.
Best and worst month in Iowa: Jul 157, Dec 63 kWh per kW
| Iowa month | kWh per kW | Price ¢ | Value per kW | kWh per kW per sun unit |
|---|---|---|---|---|
| Jan | 69.5 | 11.99 | $8.33 | 0.87 |
| Feb | 89.6 | 12.14 | $10.88 | 0.84 |
| Mar | 115.2 | 12.48 | $14.38 | 0.82 |
| Apr | 128.3 | 13.34 | $17.12 | 0.79 |
| May | 148.3 | 14.16 | $21.00 | 0.77 |
| Jun | 150.0 | 15.33 | $23.00 | 0.75 |
| Jul | 156.9 | 15.31 | $24.02 | 0.74 |
| Aug | 140.2 | 15.58 | $21.84 | 0.75 |
| Sep | 129.2 | 14.79 | $19.11 | 0.77 |
| Oct | 102.8 | 13.48 | $13.86 | 0.81 |
| Nov | 79.1 | 13.55 | $10.72 | 0.83 |
| Dec | 63.4 | 12.60 | $7.99 | 0.86 |
Iowa: December to February give 16% of a year (rank 13 of 51, 1 = most winter); the best month is 2.5 times the worst. Output per unit of sun is highest in Jan (0.87) and lowest in Jul (0.74); PVWatts lowers cell output when the panel is hot, and the sun angle changes with the season. Our runs use one fixed 14% loss figure for every place, so snow or soiling in Iowa is not modelled separately.
Sun inside Iowa: 5 cities, 6% apart
| Iowa city | kWh per kW a year | Against state point | Sun, kWh/m2 a day | Payback at $3.00 | Residents |
|---|---|---|---|---|---|
| Des Moines | 1,367 | -0.4% | 4.75 | 16.0 | 212,464 |
| Cedar Rapids | 1,360 | -0.9% | 4.70 | 16.1 | 136,859 |
| Davenport | 1,371 | -0.1% | 4.78 | 16.0 | 101,083 |
| Sioux City | 1,403 | +2.2% | 4.88 | 15.6 | 85,651 |
| Waterloo | 1,324 | -3.5% | 4.58 | 16.5 | 66,947 |
Iowa state point 41.92, -93.04; city points Des Moines 41.57, -93.61; Cedar Rapids 41.97, -91.68; Davenport 41.56, -90.60; Sioux City 42.49, -96.39; Waterloo 42.49, -92.35. Panel and method: solar method.
Output by month in Iowa cities: 12 rows
| Iowa month | Des Moines | Cedar Rapids | Davenport | Sioux City | Waterloo |
|---|---|---|---|---|---|
| Jan | 80.0 | 78.6 | 73.3 | 74.0 | 71.7 |
| Feb | 89.9 | 91.9 | 91.9 | 100.8 | 82.2 |
| Mar | 119.7 | 121.9 | 116.3 | 121.7 | 119.5 |
| Apr | 126.2 | 123.7 | 119.0 | 126.2 | 124.5 |
| May | 140.9 | 140.3 | 138.0 | 147.9 | 143.0 |
| Jun | 149.7 | 145.4 | 151.4 | 145.7 | 138.2 |
| Jul | 148.8 | 150.3 | 152.5 | 156.2 | 152.8 |
| Aug | 135.8 | 139.4 | 148.7 | 143.2 | 137.0 |
| Sep | 120.9 | 122.0 | 127.3 | 125.7 | 127.0 |
| Oct | 105.1 | 100.3 | 106.3 | 108.9 | 92.5 |
| Nov | 79.3 | 79.8 | 73.3 | 82.7 | 73.3 |
| Dec | 70.7 | 66.4 | 72.7 | 70.1 | 62.5 |
Iowa: 5 cities, best month 156 and worst 62 kWh per kW across them.
CSVIowa: payback 15.9 years, rank 38 of 51
| Measure | Value | Rank of 51 | Median state |
|---|---|---|---|
| Output of 1 kW a year, kWh | 1,373 | 25 | 1,372 |
| Home price, ¢ per kWh | 13.72 | 36 | 15.37 |
| Value of 1 kW a year | $188 | 38 | $222 |
| Payback at $3.00 a watt | 15.9 years | 38 | 13.5 years |
EIA-861 (2024): 18,108 home net-metered systems in Iowa, 12.5 per 1,000 accounts (rank 27), average 7.4 kW.
Sizes and prices per watt in Iowa
| Iowa kW | kWh a year | Value a year | Cost at $2.50 | At $3.00 | At $3.50 | t CO2 |
|---|---|---|---|---|---|---|
| 4 | 5,490 | $753 | $10,000 | $12,000 | $14,000 | 1.6 |
| 6 | 8,236 | $1,130 | $15,000 | $18,000 | $21,000 | 2.4 |
| 8 | 10,981 | $1,507 | $20,000 | $24,000 | $28,000 | 3.1 |
| 10 | 13,726 | $1,883 | $25,000 | $30,000 | $35,000 | 3.9 |
| 12 | 16,471 | $2,260 | $30,000 | $36,000 | $42,000 | 4.7 |
| Iowa $ per watt | 100% retail | 75% | 50% | 25% |
|---|---|---|---|---|
| $2.00 | 10.6 | 14.2 | 21.2 | 42.5 |
| $2.50 | 13.3 | 17.7 | 26.6 | 53.1 |
| $3.00 | 15.9 | 21.2 | 31.9 | 63.7 |
| $3.50 | 18.6 | 24.8 | 37.2 | 74.3 |
| $4.00 | 21.2 | 28.3 | 42.5 | 85.0 |
Iowa: 1,373 kWh/kW × 13.72 ¢ = 188 a year per kW; the 30% column (11.2 years at $3.00) is arithmetic only.
CSVUtility-scale solar in Iowa: 701 MW
Iowa: 701 MW of operable utility-scale solar in 37 plants across 27 counties (EIA-860, 2025), rank 34 of 51; 219 W per resident, rank 31. Solar made 1.7% of Iowa's net generation in 2025 (EIA-923), rank 37, -5.1 points against the national share. Biggest plants: Pleasant Creek Unit 2 in Linn County, 150 MW (2024); Wever Solar (150MW) in Lee County, 150 MW (2024); Holliday Creek Solar in Webster County, 100 MW (2022). By county: Linn 204 MW, Lee 150 MW, Louisa 100 MW, Webster 100 MW. Proposed: 250 MW under construction (2 plants) and 526 MW planned (5 plants); batteries 11 MW running and 99 MW proposed.
| Iowa year | MW added | Cumulative share of today's MW |
|---|---|---|
| 2019 | 6 | 1% |
| 2020 | 5 | 2% |
| 2021 | 100 | 16% |
| 2022 | 144 | 36% |
| 2023 | 0 | 36% |
| 2024 | 417 | 96% |
| 2025 | 20 | 99% |
Net metering and CO2 in Iowa
EIA-861 (2024): 18,108 home net-metered systems in Iowa, 12.5 per 1,000 accounts (rank 27), average 7.4 kW.
6 kW in Iowa: 8,236 kWh a year displaces 2.4 t CO2 at 0.286 kg per kWh, -0.7 t against the average state.
Iowa utilities and solar payback
| Iowa utility | Homes | Price ¢ | Value of 1 kW | Payback at $3.00 |
|---|---|---|---|---|
| MidAmerican Energy Co | 632,436 | 11.01 | $151 | 19.8 yr |
| Interstate Power and Light Co | 417,153 | 17.90 | $246 | 12.2 yr |
| Linn County REC | 30,323 | 14.23 | $195 | 15.4 yr |
| City of Ames | 24,979 | 12.10 | $166 | 18.1 yr |
| Eastern Iowa Light & Power Coop | 20,749 | 13.56 | $186 | 16.1 yr |
| Cedar Falls Utilities | 17,772 | 10.42 | $143 | 21.0 yr |
| Midland Power Coop | 11,939 | 13.60 | $187 | 16.1 yr |
| Maquoketa Valley Rrl Elec Coop | 11,051 | 13.76 | $189 | 15.9 yr |
| Board of Water Electric & Communications | 10,123 | 12.63 | $173 | 17.3 yr |
| Iowa Lakes Electric Coop | 9,714 | 13.78 | $189 | 15.9 yr |
| North West Rural Electric Coop | 9,400 | 9.26 | $127 | 23.6 yr |
| Access Energy Coop | 8,850 | 14.95 | $205 | 14.6 yr |
Iowa among its neighbours
| Closest to Iowa | Payback, years | kWh per kW | Price, ¢ | Utility-scale solar, points of generation | Miles away |
|---|---|---|---|---|---|
| Iowa (this page) | 15.9 | 1,373 | 13.72 | 1.7 | - |
| Nebraska | +1.0 | +67 | -1.38 | -1.1 | 219 |
| Minnesota | -1.9 | -20 | +2.10 | +3.3 | 220 |
| Missouri | +0.1 | +14 | -0.23 | +0.5 | 237 |
| Wisconsin | -3.5 | -48 | +4.44 | +4.3 | 241 |
Iowa against its neighbours in the payback ranking
- -1 places, Oklahoma -0.6 years against Iowa
- +0 places, Mississippi -0.3 years against Iowa
- Iowa, rank 38: 15.9 years
- +2 places, South Dakota +0.1 years against Iowa
- +3 places, Missouri +0.1 years against Iowa
Your numbers for Iowa
Limits in Iowa
Iowa: with the old 30% credit (IRS, ended 2025) payback would be 11.2 years instead of 15.9, so the calculator starts at 0%. No Iowa export rates in our data: output counts at 13.72 ¢. All limits.
Sources for Iowa
- PVWatts v8 (NLR), 5 Iowa cities and one state point: 1,373 kWh per kW
- EIA-860 2025 and EIA-923 2025: 701 MW of solar in Iowa
- EIA-861 2024: 18,108 net-metered systems in Iowa
- EIA retail sales 2025: 13.72 ¢ per kWh in Iowa
- IRS 25D (ended 2025): 11.2 years in Iowa with it; licences and periods for Iowa
More about Iowa
Iowa electricity hub, Iowa EV charging: 482 stations, where Iowa ranks for rooftop solar, 15.9 years against 51 states, Iowa calculators.
Questions
Winter cut in Iowa solar output?
December to February give 16% of the year; Jul makes 157 kWh per kW and Dec 63.
Solar payback in Iowa?
15.9 years at $3.00 a watt; 13.3 at $2.50; 18.6 at $3.50; 1,373 kWh per kW at 13.72 ¢.
Iowa electricity from solar, what share?
1.7% of 2025 net generation, rank 37 of 51, -5.1 points against the nation.
Where in Iowa is solar best?
Yes: 6% between Waterloo and Sioux City in yearly output.
Iowa utility-scale solar capacity?
701 MW in 37 plants (EIA-860), 219 W per resident, rank 31; 776 MW proposed.
Iowa sunshine for solar panels?
1,373 kWh per kW a year at the state point, rank 25 of 51; from 1,324 in Waterloo to 1,403 in Sioux City.
Net metering in Iowa?
18,108 systems, 12.5 per 1,000 accounts, rank 27.
Iowa pays half price for exports?
Payback 31.9 years at a 50% retail share.
CO2 displaced in Iowa?
2.4 t a year on 6 kW at 0.286 kg per kWh.
Federal solar credit in Iowa: still available?
Ended 2025 (IRS 25D); with it Iowa payback would be 11.2 years, not 15.9.