Solar permitting, licensing & interconnection in Washington
What homeowners and installers need to know about pulling permits, getting interconnected, and working under Washington contractor licensing rules — with direct links to government and utility resources.
License needed
Electrical (state) + General Contractor
Net metering
Full retail net metering
Typical permit
10–25 business days
Avg permit fee
$200–$600 typical residential (including both building and electrical permits)
Going solar in Washington: the process
1. Pick a licensed installer. Washington requires installers to hold a Washington Electrical Contractor License + WA Contractor Registration (Electrical (state) + General Contractor) issued by Washington Department of Labor & Industries (L&I). Always verify your contractor's license is active before signing.
2. Sign the contract and submit permits. Seattle, Tacoma, Spokane, and Bellevue have online permit submission portals. Both city building permits and L&I electrical permits are typically required; some jurisdictions consolidate.
3. Installation. Most residential rooftop installs take 1–3 days of on-site work. Your contractor coordinates the timing and any roof staging.
4. Final inspection. The local AHJ inspects your install. Once passed, your installer submits the interconnection application to your utility.
5. Permission to Operate (PTO). Puget Sound Energy, Seattle City Light, Tacoma Power, Snohomish PUD, and other Washington utilities all handle interconnection. Most residential under-25-kW systems are reviewed within 30–60 days.
Total typical timeline: 6–12 weeks from contract to PTO.
Net metering in Washington
Washington requires investor-owned utilities (Puget Sound Energy, Avista, PacifiCorp) and most public utility districts to offer full retail net metering for residential systems up to 100 kW. Excess credits roll over monthly and reset annually.
Official net metering reference ↗Incentives summary
30% federal Residential Clean Energy Credit (ITC). Washington Solar Plus Production Incentive (paid per kWh produced, currently in transition). Sales tax exemption on solar equipment. Property tax exemption on added home value.
Doing solar work in Washington: licensing & compliance
Required license: Washington Electrical Contractor License + WA Contractor Registration
Issued by: Washington Department of Labor & Industries (L&I)
- •Washington Electrical Contractor (EC) license — required for any electrical work.
- •WA Contractor Registration (general — required for any home improvement work above $500).
- •Workers' compensation and surety bond ($12,000 minimum for general contractor).
- •Optional: solar-specific NABCEP credential recognized by Washington Solar Plus program.
Permitting governance
Municipal — each WA city or county AHJ. Electrical permits are issued by Washington L&I (state) or by local jurisdictions that have been delegated authority (most major cities).
Interconnection process
Typical timeline: 30–60 days for PTO after install completion
Puget Sound Energy, Seattle City Light, Tacoma Power, Snohomish PUD, and other Washington utilities all handle interconnection. Most residential under-25-kW systems are reviewed within 30–60 days.
Installer resources
All Washington resources
This guide was last reviewed 2026-06-03. Permitting, licensing, and incentive rules change. Always verify current requirements with the linked agencies before sizing a project.
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