Solar Panel Cost & Savings in Washington (June 2026)
A typical 6.0 kW rooftop solar system in Washington costs about $18,000 gross ($3.00/W installed), or $12,600 after the 30% federal tax credit. It produces 6,150 kWh/year, saving about $917/year, with payback in about 13.7 years.
Washington installed cost: $3.00/watt (state avg, 2026). 20-year net savings after install cost: $5,738.
Production & savings breakdown
| Annual production | 6,150 kWh |
| Annual electricity savings | $917 |
| Peak sun hours in Washington | 3.6 hours/day |
| Electricity rate (June 2026) | 14.91¢/kWh |
| 20-year net savings (savings − net install cost) | $5,738 |
Solar incentives available in Washington
- Federal ITC: 30% of gross install cost ($5,400 on this system), valid through 2032.
- State tax credit: None (production incentive expired 2020)
- Net metering: Yes, 1:1
- Property tax exemption: No.
- Sales tax exemption: Yes — no sales tax on solar equipment.
Sales tax exemption 100%. Low electricity rates ($0.14/kWh) make solar payback slower.
Customize for your home
Plug in your own system size and the electricity rate you actually pay. Calculations update instantly.
Formula: annual_kWh = system_kW × peak_sun_hours × 365 × 0.78 · annual_savings = annual_kWh × rate
About solar in Washington
Washington averages 3.6 peak sun hours per day, derived from NREL’s solar resource data. Combined with the Washington residential electricity rate of 14.91¢/kWh (EIA, June 2026), this gives a typical 6.0-kW system the production and savings figures above. Compared to the U.S. average, Washington’s sun resource is 20% below the national mean.
Estimates assume a roof-mounted system with the PVWatts default performance ratio (0.78), $3.00/watt installed (national average), and the U.S. federal Investment Tax Credit at 30% (in effect through 2032).
Solar savings across other states (same 6.0-kW system)
| State | Peak sun hrs | Annual savings |
|---|---|---|
| Hawaii | 5.7 | |
| California | 5.6 | |
| Rhode Island | 4.0 | |
| Massachusetts | 3.9 | |
| Maine | 3.9 | |
| New York | 3.8 | |
| New Hampshire | 3.9 | |
| District of Columbia | 4.3 | |
| New Jersey | 4.2 | |
| Arizona | 6.5 | |
| Connecticut | 4.0 | |
| Washington | 3.6 |
Solar & energy gear
Affiliate links — we may earn a small commission at no cost to you.
- 100W portable solar panel — DIY / RV starter
- EcoFlow / Jackery portable power station
- Solar production monitor
- Sense Solar energy monitor — track produced vs. consumed
FAQ
Are these savings guaranteed?
No estimate is — your actual savings depend on roof orientation, shading, your specific utility plan, and how much of the solar production you self-consume versus export. The numbers here represent a well-sited, unshaded south-facing roof.
What does “peak sun hours” mean?
One peak sun hour = the energy equivalent of 1 hour at 1,000 W/m² irradiance. A 3.6-PSH location delivers, on an annual average, the same total energy each day as 3.6 hours of full-strength sunlight.
Do these numbers include net metering?
The savings calculation assumes you offset retail electricity at the displayed rate. In states with full retail net metering, this is accurate. In states with reduced export rates, savings on grid-exported kWh will be lower — check your utility’s policy.
What if I am in Washington but my utility charges a different rate?
Use the customization box above to enter your actual rate. The math is yours, so the result will match your bill.