Solar Payback Period in Washington
Estimated payback, savings, and ROI for a residential solar system in Washington — updated for 2026
Urgent tax credit deadlines
- Section 30D EV credit (up to $7,500) — expires June 30, 2026 (12 days left).
- Section 48E solar ITC safe harbor — construction must start by July 4, 2026 (16 days left).
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Solar ROI Overview for Washington
Based on Washington's average of 3.7 peak sun hours per day and utility rates of $0.188/kWh, a typical 7kW residential solar system in Washington would:
- Cost approximately $21,700 before incentives
- Generate about 7,279 kWh/year
- Save you $1,368/year ($114/month)
- Pay for itself in 15.9 years
- Deliver a 58% ROI over 25 years
Washington has lower sun hours than the national average, but solar can still make financial sense depending on your local utility rates and available incentives.
Payback by System Size in Washington
| System Size | Cost | Production | Annual Savings | Payback | 25yr ROI |
|---|---|---|---|---|---|
| 4 kW | $12,400 | 4,160 kWh | $782 | 15.9 yrs | 58% |
| 5 kW | $15,500 | 5,199 kWh | $977 | 15.9 yrs | 58% |
| 6 kW | $18,600 | 6,239 kWh | $1,173 | 15.9 yrs | 58% |
| 7 kW | $21,700 | 7,279 kWh | $1,368 | 15.9 yrs | 58% |
| 8 kW | $24,800 | 8,319 kWh | $1,564 | 15.9 yrs | 58% |
| 10 kW | $31,000 | 10,399 kWh | $1,955 | 15.9 yrs | 58% |
How Solar Payback Works in Washington
Solar payback period is the time it takes for your cumulative electricity savings to equal the total cost of your solar system. In Washington, the calculation depends on three key factors:
- System cost — $3.10/Watt average in Washington
- Electricity rate — $0.188/kWh average utility rate
- Solar production — 3.7 average peak sun hours/day
After the payback period of 15.9 years, your solar panels continue generating free electricity for 15-20+ more years. With utility rates historically increasing 2-4% annually, your actual savings will likely exceed these estimates.
Washington Solar Data Summary
- Average Cost/Watt
- $3.10
- Average Utility Rate
- $0.188/kWh
- Peak Sun Hours
- 3.7 hrs/day
- Data Coverage
- 5 ZIP codes
Related Tools for Washington
Compare with Fastest Payback States
| State | Payback | Annual Savings | 25yr ROI |
|---|---|---|---|
| Washington (you) | 15.9 yrs | $1,368 | 58% |
| Louisiana | 11.8 yrs | $1,537 | 111% |
| South Dakota | 13.5 yrs | $1,452 | 85% |
| West Virginia | 13.7 yrs | $1,433 | 83% |
| Minnesota | 13.8 yrs | $1,574 | 81% |
| Kentucky | 13.9 yrs | $1,359 | 80% |
📖 Complete Guide to Solar ROI
Want to understand every factor that affects your solar payback period? Read our comprehensive guide covering financing options, NEM policies, and how to maximize your returns.
Read: Complete Guide to Solar ROI in 2026 →