Solar Panel Calculator for Riverside, CA
Estimate the cost, savings and payback of solar panels in Riverside, CA, using local NREL sunshine data, California prices and electricity rates.
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Riverside gets about 6.20 peak sun hours a day on a south-facing roof, so each kW of panels makes about 1,695 kWh a year. That ranks #11 of the 111 cities on this site. Output peaks in Jul and is lowest in Dec.
Sunshine in Riverside by month
What an 8 kW system makes in Riverside
| Month | Sun hours a day | Output | Bill savings |
|---|---|---|---|
| Jan | 4.54 | 880 kWh | $287 |
| Feb | 5.11 | 888 kWh | $289 |
| Mar | 6.05 | 1,144 kWh | $373 |
| Apr | 6.76 | 1,224 kWh | $399 |
| May | 7.03 | 1,296 kWh | $422 |
| Jun | 7.67 | 1,344 kWh | $438 |
| Jul | 7.83 | 1,416 kWh | $461 |
| Aug | 7.61 | 1,360 kWh | $443 |
| Sep | 6.81 | 1,200 kWh | $391 |
| Oct | 5.90 | 1,080 kWh | $352 |
| Nov | 4.93 | 912 kWh | $297 |
| Dec | 4.15 | 824 kWh | $268 |
| Year | 6.20 | 13,560 kWh | $4,418 |
Savings at 32.58¢ per kWh (California average), with every kWh credited at that price.
Cost and payback by system size
At $2.52 per watt, the California average, before incentives.
| System | Cost | Year 1 savings | Payback | 25-yr gain |
|---|---|---|---|---|
| 4 kW | $10,080 | $2,209 | 4.6 yrs | $41,953 |
| 6 kW | $15,120 | $3,313 | 4.6 yrs | $62,930 |
| 8 kW | $20,160 | $4,418 | 4.6 yrs | $83,907 |
| 10 kW | $25,200 | $5,522 | 4.6 yrs | $104,883 |
| 12 kW | $30,240 | $6,627 | 4.6 yrs | $125,860 |
How many panels you need in Riverside
| Monthly use | System | 400 W panels |
|---|---|---|
| 500 kWh | 3.54 kW | 9 |
| 750 kWh | 5.31 kW | 14 |
| 1,000 kWh | 7.08 kW | 18 |
| 1,500 kWh | 10.62 kW | 27 |
| 2,000 kWh | 14.16 kW | 36 |
Covering 100% of a year's use at 1,695 kWh per kW.
Common questions
Is solar worth it in Riverside?
At local averages an 8 kW system costs about $20,160 before incentives, saves about $4,418 in its first year and pays back in about 4.6 years.
How many peak sun hours does Riverside get?
About 6.20 a day over the year on a south-facing roof at 20°, from 4.2 in Dec to 7.8 in Jul, according to NREL's PVWatts model.
How much does a 1 kW solar system produce in Riverside?
About 1,695 kWh a year, or 141 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