Solar panels in Seattle, WA: cost and payback (2026)
Solar panels in Seattle cost about $23,200 installed for an 8 kW system, and $23,200 net. There is no federal homeowner credit in that figure — the 30% credit ended for systems placed in service after December 31, 2025. At 11.5¢ per kWh that system offsets roughly $83 a month and pays itself back in 23.3 years — assuming Seattle City Light, which serves most of Seattle, credits what you export.
Cost, rate and sun hours are Washington statewide figures from EIA and NREL — we do not publish a separate Seattle rate or sun-hour value we cannot source. The utility is the part that is genuinely local, and it is the part that changes the answer most. Incentives are modelled for today’s date, so nothing expired is counted.
Seattle City Light: what it means for solar in Seattle
Seattle City Light serves most of Seattle. It is municipal / public power utility — owned by the city or a public district and governed by its own board or council rather than the state commission — which means the statewide net metering rule generally does not bind it, and its export credit is set locally and can be changed locally.
Because Seattle City Light is municipal / public power utility, the Washington rule below usually does not bind it, and its own board sets the terms. For reference, the statewide position is: Washington guarantees retail-rate net metering through at least 2029, and solar equipment is exempt from state sales tax. Treat that as context, not as your contract.
Whichever it is, this is the first question to settle and the one installers are least specific about. Ask for the rider or tariff name, the per-kWh export credit, how long that credit is locked for, and the current interconnection turnaround — in the written quote, not in conversation. Service territories cut across city limits, so confirm against the name at the top of your own bill.
Cost by system size in Seattle
Within one city, quotes still spread. A steep or cut-up roof costs more in labour than a simple south-facing plane. A main service panel at capacity adds a four-figure upgrade before a single module goes up. Two storeys costs more than one. None of that shows up in a per-watt average, which is why the table below is a starting point rather than a quote.
| System | Panels | Gross cost | Net cost | Yr 1 savings | Payback |
|---|---|---|---|---|---|
| 6 kW | 15 | $17,400 | $17,400 | $745 | 23.3 yrs |
| 8 kW | 20 | $23,200 | $23,200 | $994 | 23.3 yrs |
| 10 kW | 25 | $29,000 | $29,000 | $1,242 | 23.3 yrs |
Modelled, not quoted. Production is system size × 3.7 peak sun hours × 365 days × 0.8 for inverter, wiring, soiling and heat losses. Savings value that production at 11.5¢ per kWh and hold the rate flat for year one. Panel count assumes 400 W modules. Your roof, your shade and your usage move all of it.
No federal credit is in these numbers. The 30% homeowner credit (IRC Sec. 25D) ended for systems placed in service after December 31, 2025. Net cost above is gross cost minus whatever state or local money is still open — nothing else. If a quote knocks 30% off and calls it a federal credit, ask which statute they are citing.
Permits and approvals in Seattle
Two approvals, one landlord. The Seattle building department issues the electrical and structural permit, and Seattle City Light — which the city also owns — issues permission to operate. That is usually a shorter path than it is in an investor-owned territory, because both desks answer to the same government. It also means there is no state commission to appeal to if you do not like the answer; the recourse is the council or the utility board, in public, at a meeting.
Permit fees and turnaround vary by jurisdiction and we do not track them, so we are not going to print a number we cannot source. Make the installer put the permit cost and the expected wait for both approvals in the written quote instead of leaving them as a line you discover afterwards.
Incentives and the full state picture: solar panels in Washington.
Questions from Seattle
How much do solar panels cost in Seattle?
A 8 kW system in Seattle models at $23,200 installed and $23,200 net, at the Washington average of $2.90 per watt. There is no federal homeowner credit in that — the 30% credit ended for property placed in service after December 31, 2025. Quotes inside one city still vary by several thousand dollars depending on roof pitch, panel choice and whether the main service panel needs upgrading.
Who is the electric utility in Seattle?
Seattle City Light serves most of Seattle. It is municipal / public power utility — owned by the city or a public district and governed by its own board or council rather than the state commission — which means the statewide net metering rule generally does not bind it, and its export credit is set locally and can be changed locally. That matters more than it sounds: your utility, not your installer and not the state, sets what an exported kWh is worth and how long permission to operate takes. Service territories cut across city limits, so check the name at the top of your own bill.
Should I add a battery in Seattle?
It depends entirely on what Seattle City Light pays for exports. Where exports are credited at or near the full retail rate, the grid is already a free battery and a real one rarely pays for itself. Where exports are credited well below retail — which is the direction most tariffs have moved — storing your own afternoon production and using it at night is worth more than selling it. Get the export credit in writing first, then price the battery against it.
Does Seattle City Light pay for solar you send back to the grid?
Seattle City Light is municipal / public power utility, which generally puts it outside the state rule — Washington guarantees retail-rate net metering through at least 2029, and solar equipment is exempt from state sales tax. That is the statewide position, but a municipal utility sets its own export credit. Get Seattle City Light's current residential solar tariff in writing rather than assuming the state rule covers you.
Is solar still worth it in Seattle now the federal tax credit is gone?
On these numbers it pays back in about 23.3 years with no federal credit at all — $23,200 net against roughly $994 of electricity offset a year. Washington runs no state rebate either, so $23,200 is the whole price. What decides it in Seattle is the 11.5¢ per kWh you pay now and what Seattle City Light credits your exports at, not the subsidy that ended.
Where to look next
Incentives, electricity rates, net metering rules and the full Washington picture live on the state page: solar panels in Washington.