Washington vs Idaho Solar Incentives: Which State Gets the Better Deal?
Side-by-side comparison of Washington and Idaho solar incentive programs in 2026: state tax credits, net metering rules, exemptions, payback period, and projected 25-year savings.
| Metric | WA · Washington | ID · Idaho |
|---|---|---|
| Avg Monthly Bill | $110 | $115 |
| Peak Sun Hours / Day | 3.8 | 5 ◆ |
| Avg $/Watt Installed | $2.85 | $2.8 ◆ |
| State Tax Credit | None | None |
| Net Metering | retail | avoided-cost |
| SREC Market | No | No |
| Property Tax Exempt | No | No |
| Sales Tax Exempt | Yes | No |
| Payback, pre-credit model (yrs) | 9.8 ◆ | 10.2 |
| 25-yr savings, pre-credit model | $26,200 ◆ | $24,800 |
Payback and 25-year savings were modeled while the federal residential credit applied. They are not a 2026 quote. The calculator uses $0 federal credit and state incentives only.
State Tax Credit Comparison
Washington offers no state income tax credit. Idaho offers no state income tax credit.
Net Metering Policies
Washington: retail rate net metering active. Idaho: avoided-cost rate net metering active.
Net metering is often the most economically significant solar policy because it determines how excess production is valued. Retail-rate states (where you receive full retail price for exported energy) have substantially better solar economics than avoided-cost or no-net-metering states.
Average 25-Year Savings
Washington: $26,200 over 25 years (avg payback 9.8 yrs). Idaho: $24,800 over 25 years (avg payback 10.2 yrs).
Verdict: Which State Wins on Solar?
Washington edges out Idaho on lifetime savings primarily due to more favorable net metering rules.
Note: state averages mask significant within-state variation. Your specific utility, roof orientation, and household electricity profile drive your actual numbers — use the calculator to model your home directly.