State solar guide
Washington solar economics in 2026 depend entirely on your utility rate, available state incentives, and net-metering rules. The federal residential credit expired December 31, 2025. We present the honest picture for your location.
Sources: ElectricChoice June 2026 | NREL PVWatts (Seattle averages 3.5 to 4.0 peak sun hours per day; Eastern Washington averages 4.5 to 5.5 hours per day in Spokane, Yakima, and Tri-Cities) | EnergySage May 2026 | Federal residential credit: Section 25D expired December 31, 2025, H.R.1 (One Big Beautiful Bill Act).
Net metering
Washington state law requires electric utilities to offer net metering for residential systems up to 100 kW AC. The major utilities - Puget Sound Energy (PSE), Seattle City Light, Snohomish County PUD, and Avista - all offer 1:1 full retail-rate net metering. Monthly credits roll over and are cleared annually on March 31; excess credits at the annual settlement are cleared (not paid out). Grays Harbor PUD is an exception: it compensates at 50% of the retail rate, which significantly reduces economics for customers in that service territory. Washington has no state income tax and therefore no income-tax-based solar credits are possible.
Grays Harbor PUD's 50% retail compensation is a meaningful outlier in an otherwise full-retail state. PSE and Seattle City Light serve most of Western Washington - both offer full retail. Avista serves much of Eastern Washington (Spokane metro) with full retail metering. Snohomish County PUD covers the Snohomish and Island County areas with full retail metering. Annual credit clearing on March 31 makes system right-sizing important - overproduction that is not consumed locally by March 31 is forfeited.
Program: NM1_full_retail. Last verified: June 1, 2026. DSIRE source (opens in new tab).
Verify with your utility
Net-metering rules change by utility and program cycle. Confirm current export credit rates and eligibility with your specific Washington utility before contracting. Current program details at DSIRE (opens in new tab).
State incentive stack
The federal residential credit expired December 31, 2025. The programs below are what remains for Washington homeowners. Amounts and availability change; every program is date-stamped and linked to its DSIRE source.
Federal residential solar credit (Section 25D): expired. The Section 25D residential investment tax credit expired December 31, 2025. The residential credit rate is 0%. State and local incentives below may still significantly reduce your net system cost. Commercial systems still qualify for Section 48E (30%).
| Program | Benefit | Eligibility | Status | Source |
|---|---|---|---|---|
| Washington Solar and Wind Energy Sales Tax Exemption Sales and use tax exemption Exemption is set to expire December 2029 under current law. Confirm that your contractor properly codes the sale as exempt. Local rates vary - the savings amount is higher in high-tax jurisdictions like King County and Snohomish County. | Typically $2,800 to $3,575 on a typical $35,000 residential installation (varies by county rate) Solar energy systems under 100 kW AC are exempt from Washington state and local retail sales tax and use tax through December 2029. Saves 8.6% to 10.25%+ depending on county. | Purchases of qualifying solar energy systems under 100 kW AC for installation in Washington state, through December 2029. | Active | DSIRE (opens in new tab) |
| Washington Solar Property Tax Exemption Property tax exemption Confirm exemption filing requirements with your county assessor. | Exemption on solar-added home value (amount varies by local tax rate and system size) Washington's property tax treatment of solar is contested among sources. Residential property owners should verify with their specific county assessor before relying on any property tax exclusion. The sales tax exemption is the unambiguous incentive. | Washington residential property owners with qualifying solar installations. | Active | DSIRE (opens in new tab) |
Data last verified June 1, 2026. Incentive programs change; verify current amounts and availability at dsireusa.org (opens in new tab) before committing to a project.
Savings example
This example uses real Washington market data. No federal residential credit is applied. Figures are illustrative; your in-home assessment uses your actual utility bills and the current rate schedule for your specific utility.
System size 14 kW at market average of $2.68 per watt. Annual production estimated at 14,000 kWh based on Seattle at 3.5 to 4.0 peak sun hours per day (NREL PVWatts, lower end due to Western Washington cloud cover). Assumes 75% self-consumption at $0.1411 per kWh retail value; 25% exported at full retail rate via PSE net metering. Annual credit clearing March 31. Utility rate escalation at 3% annually. Federal residential credit: $0 (expired). State credit: $0 (none available). Eastern Washington customers on Avista territory with 4.5 to 5.5 peak sun hours see materially better economics (9 to 12 year payback range). Figures are illustrative; your in-home assessment will use your actual bills.
Washington PSE customer - Western WA (illustrative)
Illustrative example. Federal residential credit: $0 (Section 25D expired December 31, 2025). Your estimate will use your actual utility bills and current rate schedule.
Permitting
Washington does not have a statewide residential solar permit fee cap. Permit fees and timelines vary significantly by jurisdiction. King County (Seattle metro) permit processes are among the more established in the state - City of Seattle and unincorporated King County have streamlined solar permit workflows. Spokane and Eastern Washington jurisdictions tend to have faster processing due to lower volume. The Washington State Building Code Council has adopted solar-friendly provisions that standardize some permit requirements. PSE and Seattle City Light interconnection reviews add 4 to 10 weeks after permit issuance. Total contract-to-energization time in Western Washington typically runs 10 to 18 weeks; Eastern Washington 8 to 14 weeks.
Washington's dramatic regional variation in sun resource (Seattle 3.5 to 4.0 hours vs Spokane 4.5 to 5.5 hours) is more significant than permit timeline differences. Eastern Washington's better sun and potentially faster permits combine to create meaningfully better solar economics than Western Washington. Pierce County, Thurston County, and Clark County each have separate permit processes.
Commercial solar in Washington
The commercial solar credit (Section 48E, 30 percent) remains available for qualifying commercial projects. Construction must begin by July 4, 2026 to qualify for the full placed-in-service window. Combined with MACRS accelerated depreciation and 100 percent first-year bonus depreciation, the combined first-year federal benefit can reach 45 to 55 percent of project cost for many Washington business owners. Direct Pay is also available for nonprofits, municipalities, and other tax-exempt entities.
Commercial solar overviewCommercial solar projects must begin construction by July 4, 2026 to qualify for the 30 percent Section 48E federal tax credit. After that date, the system must be placed in service by December 31, 2027.
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Frequently asked
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