Average Solar Panel Installation Cost in Washington
$21,580
Low End
$14,813
Average
$21,580
High End
$28,225
Want a more precise estimate?
Use our free Solar calculatorHere's how solar panel installation costs typically break down in Washington:
Solar Panel Installation in Washington is 2% below the national average of $22,085. This is primarily due to higher labor costs and stronger demand in Washington.
Washington experiences a mild marine climate west of the Cascades with wet, cool winters and dry summers, shifting to a cold semi-arid continental climate east of the mountains in the Columbia Basin and Palouse. Persistent rain from October through May compresses exterior windows west of the crest, while Spokane and eastern Washington face real snow and freeze loads. For solar panel installation projects specifically, this means timing and material selection are key factors in both cost and quality.
Stricter building codes and inspection requirements in this state contribute to higher permit and compliance costs.
Washington State L&I requires all contractors to be registered (General or Specialty), verify active registration and bond at lni.wa.gov before any contract
The 2021 Washington State Energy Code (WSEC-R), effective March 2024, is among the most stringent in the country, plan for 5-9 energy credits on new construction
Puget Sound Energy, Seattle City Light, and Snohomish PUD run active 2026 rebates for heat pumps, weatherization, and smart thermostats
West-of-Cascades projects are largely October-through-April weather-limited for exteriors, schedule dry-season trades (siding, roofing, painting) in May-September slots
Most solar panel installation projects in Washington require a building permit, especially if structural changes are involved. Estimated permit cost: $468.
View full permit guide for WashingtonShare your project once and we'll send it to up to 3 verified solar-panel-installation pros in your area. Free for you, free for them. Never shared with more than 3, and never with anyone we have not verified.
Solar Panel Installation in Washington typically costs between $14,813 and $28,225, with an average of $21,580 for a typical project in 2026.
No, solar panel installation in Washington is about 2% below the national average, making it more affordable than many other states.
Permit requirements vary by city and county in Washington. Most solar panel installation projects that involve structural changes require a building permit. Check our permit guide for Washington for specific requirements.
A typical solar panel installation project takes 2-7 days depending on the scope, weather conditions, and contractor availability in your area.
Get at least 3 quotes from licensed contractors, consider scheduling during off-peak seasons (fall/winter), ask about financing options, and make sure to compare material options as they significantly affect the total cost.
Cost estimates are based on publicly available data and industry averages for Washington. Actual costs vary significantly based on project specifics, contractor pricing, material choices, and local market conditions. These estimates are for informational purposes only. Always get multiple quotes from licensed contractors.