Why there is no state credit to fall back on
Washington levies no personal income tax. A state income tax credit is a reduction in state income tax owed, so a state without the tax cannot offer the credit.
This is not a policy gap that might be filled next session. It is structural, and it means the familiar pattern of a federal credit stacked on a state credit has never applied here.
A great deal of national solar material assumes that stack, which is why guides can leave a Washington reader with an inflated sense of what is available. If you read about combining a federal and state credit, you are reading about somewhere else.
What Washington offers instead is a tax exemption at purchase rather than a credit at filing, plus net metering. Those are real, and they are the whole of it at state level.
What ended federally, and what did not
The 30 percent federal Residential Clean Energy Credit under Section 25D expired for property placed in service after December 31, 2025. A cash or loan purchase now receives no federal tax credit.
Section 48E, the commercial credit, survives at 30 percent and is available to third-party owners of residential systems under leases and power purchase agreements. The provider claims it, and whether any value reaches you depends on the rate you are offered.
That is why third-party ownership is being pushed harder in 2026. In a state with no offsetting credit of its own, it is the only route by which a 30 percent federal credit touches a Kent rooftop at all.
Evaluate it as a rate rather than as a credit. Ask for the side-by-side against a cash purchase on the same system over the same term, with the sales tax exemption and net metering treated identically in both.
What is actually left, itemised
The sales and use tax exemption under RCW 82.08.962 and 82.12.962 gives a 100 percent exemption from state and local sales and use tax on residential systems up to 100 kW AC, through December 31, 2029, covering installation labour as well as equipment.
Net metering under RCW 80.60 credits excess kilowatt hours at the retail rate on the following period bill, subject to the April 30 forfeit of unused credit to the utility.
Your own utility may run programmes of its own on top of that, which is worth asking about directly rather than assuming from a statewide guide.
And the electricity you stop buying, which is the largest term and the one that does not depend on any programme staying open. Ask for the projection built from those items alone, each named and itemised.
Rebuilding the Washington arithmetic
Strike the federal residential credit from any quote that shows it, since Section 25D expired for property placed in service after December 31, 2025.
Strike any state tax credit, because Washington does not have one and never has.
Rebuild from the sales and use tax exemption, retail-rate net metering with the April 30 forfeit, any programme your own utility runs, and the electricity you stop buying at your actual rate.
Ask for that version in writing with each line named. An installer working Washington seriously in 2026 will already have it, and a quote that cannot itemise what it is claiming is a quote you cannot check.