Idaho vs Washington Solar Comparison
Idaho gets more sun (4.7 hrs/day) while Idaho has the faster payback (12.5 years).Washington offers higher 20-year savings at $22,800.
Idaho
4.7 hrs
12.5yr payback
$22,400
20yr savings
Washington
3.5 hrs
12.5yr payback
$22,800
20yr savings
Side-by-Side Comparison
| Metric | Idaho | Washington |
|---|---|---|
| Peak Sun Hours | 4.7 hrs | 3.5 hrs |
| Cost per Watt | $3.00 | $3.10 |
| 6kW System Cost | $18,000 | $18,600 |
| Federal Tax Credit | 30% | 30% |
| State Tax Credit | None | None |
| State Rebate | None | None |
| Net Metering | Full Net Metering | Full Net Metering |
| Electricity Rate | 11.15¢/kWh | 11.26¢/kWh |
| Payback Period | 12.5 years | 12.5 years |
| 20-Year Savings | $22,400 | $22,800 |
Verdict
Washington is the better state for solar ROI with $22,800 in 20-year savings and a 12.5-year payback period. Idaho has more sun exposure at 4.7 hrs/day, making it ideal for maximum energy production. Both states qualify for the 30% federal solar tax credit.
Frequently Asked Questions
Is solar better in Idaho or Washington?
Idaho gets more sun (4.7 peak hours/day vs 3.5). Idaho has a faster payback (12.5 years) and Washington offers higher 20-year savings ($22,800).
How do solar costs compare between Idaho and Washington?
A 6kW system costs $18,000 in Idaho vs $18,600 in Washington before incentives. Both qualify for the 30% federal tax credit.
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Data verified March 2026 · Source: NREL, DSIRE, EIA