Solar Panel Calculator for Des Moines, IA
Estimate the cost, savings and payback of solar panels in Des Moines, IA, using local NREL sunshine data, Iowa prices and electricity rates.
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Des Moines gets about 4.80 peak sun hours a day on a south-facing roof, so each kW of panels makes about 1,381 kWh a year. That ranks #68 of the 111 cities on this site. Output peaks in Jul and is lowest in Dec.
Sunshine in Des Moines by month
What an 8 kW system makes in Des Moines
| Month | Sun hours a day | Output | Bill savings |
|---|---|---|---|
| Jan | 3.02 | 656 kWh | $95 |
| Feb | 3.93 | 760 kWh | $111 |
| Mar | 4.73 | 968 kWh | $141 |
| Apr | 5.16 | 968 kWh | $141 |
| May | 5.78 | 1,104 kWh | $161 |
| Jun | 6.37 | 1,144 kWh | $166 |
| Jul | 6.71 | 1,224 kWh | $178 |
| Aug | 6.08 | 1,128 kWh | $164 |
| Sep | 5.75 | 1,056 kWh | $154 |
| Oct | 4.23 | 840 kWh | $122 |
| Nov | 3.19 | 632 kWh | $92 |
| Dec | 2.67 | 568 kWh | $83 |
| Year | 4.80 | 11,048 kWh | $1,607 |
Savings at 14.55¢ per kWh (Iowa average), with every kWh credited at that price.
Cost and payback by system size
At $3.26 per watt, the Iowa average, before incentives.
| System | Cost | Year 1 savings | Payback | 25-yr gain |
|---|---|---|---|---|
| 4 kW | $13,040 | $804 | 16.9 yrs | $5,893 |
| 6 kW | $19,560 | $1,206 | 16.9 yrs | $8,839 |
| 8 kW | $26,080 | $1,607 | 16.9 yrs | $11,786 |
| 10 kW | $32,600 | $2,009 | 16.9 yrs | $14,732 |
| 12 kW | $39,120 | $2,411 | 16.9 yrs | $17,679 |
How many panels you need in Des Moines
| Monthly use | System | 400 W panels |
|---|---|---|
| 500 kWh | 4.34 kW | 11 |
| 750 kWh | 6.52 kW | 17 |
| 1,000 kWh | 8.69 kW | 22 |
| 1,500 kWh | 13.03 kW | 33 |
| 2,000 kWh | 17.38 kW | 44 |
Covering 100% of a year's use at 1,381 kWh per kW.
Common questions
Is solar worth it in Des Moines?
At local averages an 8 kW system costs about $26,080 before incentives, saves about $1,607 in its first year and pays back in about 16.9 years.
How many peak sun hours does Des Moines get?
About 4.80 a day over the year on a south-facing roof at 20°, from 2.7 in Dec to 6.7 in Jul, according to NREL's PVWatts model.
How much does a 1 kW solar system produce in Des Moines?
About 1,381 kWh a year, or 115 kWh a month on average.
Is there a federal solar tax credit?
Not for homeowners who buy their system. The 30% Residential Clean Energy Credit ended for systems installed after December 31, 2025.
Sources
- NREL PVWatts V8 API (south-facing, 20° tilt, 14% losses, typical-year weather): https://developer.nlr.gov/docs/solar/pvwatts/v8/
- EnergySage, Solar panel cost by state (updated November 6, 2026): https://www.energysage.com/local-data/solar-panel-cost/
- U.S. EIA, Electric Power Monthly, Table 5.6.B (residential price, Jan–Aug 2026): https://www.eia.gov/electricity/monthly/epm_table_grapher.php?t=epmt_5_6_b