Is solar worth it in Washington?

Washington gets limited sunshine — about 3.5 peak sun hours a day — and residential electricity runs around $0.11/kWh. For a typical $150-a-month power bill, that points to roughly a 16.0-kW system costing about $48,034 — with no federal tax credit, which ended for installations completed after December 31, 2025 — paying for itself in about 26.7 years and netting on the order of $13,331 over 25 years. Your own numbers will differ — the calculator above uses your real bill.

Washington has the least sun and very cheap hydro electricity, so pure-savings payback is the longest in the country — solar here is more about energy independence than fast returns. The federal credit has ended, though there's a sales-tax exemption.

What changes the math in Washington

• Your electricity rate — the more you pay per kWh, the more each solar kWh saves you. Washington sits at about $0.11.
• Sun hours — more sun means a smaller, cheaper system covers the same usage. Washington averages ~3.5 hours.
• Net metering / buyback — how your utility credits power you export swings the payback; check your specific utility's current terms.
• Install cost — quotes vary by installer and roof; the calculator defaults to a typical $/watt you can override.

Washington: the rules that actually decide your payback

Who your utility is, and why it matters

Puget Sound Energy, Seattle City Light, Tacoma Power, Avista, and Pacific Power split the state, with dozens of public utilities serving the rest. All are bound by the state's net-metering law, which sets a consistent floor that makes Washington's rules unusually uniform for a state this varied.

What your exported power is worth

Washington credits exported solar at the full retail rate (1:1) for systems up to 100 kW, with the net-metering program capped at 4% of each utility's peak demand. Credits roll over month to month on a March-to-February cycle; at the annual true-up, any remaining credits are forfeited without payment — so oversizing past annual usage buys nothing in this state.

The Washington incentive layer

There is no state production incentive for residential solar anymore (the old production-payment program ended) and no state income-tax credit (Washington has no income tax). What remains is a 100% sales-tax exemption on solar equipment and installation labour, available through 2029 — meaningful in a state with a high combined sales-tax rate, and automatic at the point of sale.

Battery and self-consumption

With full-retail export and no state tax structure to optimise, Washington's battery case is almost entirely resilience: windstorm and earthquake preparedness in a state where the grid's seismic vulnerability is a documented fact. The economics of self-consumption versus export are neutral, which is rare — the battery decision here is a household-preparedness decision, full stop.

What to check on a Washington quote

• Confirm the model sizes to 100% of annual usage or less: credits forfeit at the March true-up, so oversizing wastes money by design.
• Ask whether the sales-tax exemption is reflected in the quoted price — it should be, automatically, not as a rebate to file for.
• If you are on a public utility's lines rather than an investor-owned one, confirm their net-metering cap status (the 4% threshold fills on a first-come basis in some territories).
• For battery quotes, ask about the critical-loads panel sizing and whether the inverter supports islanding during an outage.

Programme and tariff detail above is summarised from Washington UTC net metering, plus the WA Dept. of Revenue sales-tax exemption. Last reviewed 20 August 2026 by SolarDime editorial. These rules change — confirm the current terms with your utility and the regulator before you sign.