A worked example: 8 kW in Washington
An 8 kW system — about 19 × 425-watt panels — at Washington's assumed installed cost of $2.60–$3.40 per watt runs roughly $20,800–$27,200 before incentives. At about 1,050 kWh of production per installed kW, it would generate around 8,400 kWh per year. Valuing self-consumed electricity at the assumed $0.12/kWh retail rate and exports conservatively, first-year savings land near $831 — a simple payback of roughly 25–33 years.
There is no federal tax credit in that math: the Section 25D residential credit ended for systems installed after December 31, 2025. State or utility incentives, where they exist, would shorten payback from here.
Net metering in Washington
Washington requires retail-rate net metering with annual true-up (credits zeroed each spring) for systems up to 100 kW at most utilities.
Washington solar incentives
Washington exempts qualifying residential solar systems from sales tax — significant given the rate — but offers no current state production incentive for new customers.
What changes a Washington solar quote?
Equipment, roof condition, electrical upgrades, permitting, labor, system size, batteries and financing can all change the installed price. Savings also depend on the specific utility rate, how much solar electricity the home uses directly, and what the utility pays for exports.
Frequently asked questions
How much do solar panels cost in Washington?
Using an assumed installed cost of $2.60–$3.40 per watt, a typical 8 kW home system in Washington costs roughly $20,800–$27,200 before incentives. Smaller and larger systems scale roughly with size, though small systems cost more per watt.
Is solar worth it in Washington?
With Washington electricity around $0.12/kWh and production around 1,050 kWh per installed kW per year, an 8 kW system could save roughly $831 in year one, for a simple payback of about 25–33 years with no federal credit. Whether that is "worth it" depends on your rate plan, export compensation, roof, and how long you plan to stay in the home.
Does Washington have net metering?
Washington requires retail-rate net metering with annual true-up (credits zeroed each spring) for systems up to 100 kW at most utilities.
What solar incentives does Washington offer in 2026?
Washington exempts qualifying residential solar systems from sales tax — significant given the rate — but offers no current state production incentive for new customers. Note that the federal Section 25D residential credit ended for systems installed after December 31, 2025, so state, local and utility programs are now the main incentives for purchased systems.
Is there still a federal solar tax credit in Washington?
No — the 30% federal residential clean energy credit (Section 25D) ended for systems installed after December 31, 2025 under the One Big Beautiful Bill Act. Leased or PPA systems may still benefit indirectly because the system owner can claim the commercial 48E credit through 2027.
Use this as a starting point
This page provides broad state assumptions, not a current market survey or binding quote. Before purchasing, verify applicable incentives, utility rules, installer licensing, warranties and financing terms.
Where these numbers come from
State assumptions are informed by public data and reviewed periodically (September 2026):