Solar panels in Spokane, WA: cost and payback (2026)
Solar panels in Spokane 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 Avista Utilities, which serves most of Spokane, credits what you export.
Cost, rate and sun hours are Washington statewide figures from EIA and NREL — we do not publish a separate Spokane rate or sun-hour value we cannot source.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.
Avista Utilities: what it means for solar in Spokane
Avista Utilities serves most of Spokane. It is investor-owned utility — regulated by the state public utility commission, so the statewide net metering or net billing rule below is the one that applies to you, and any change to it goes through a public docket you can read.
Because Avista Utilities answers to the state commission, the Washington rule is the one that governs your exports: Washington guarantees retail-rate net metering through at least 2029, and solar equipment is exempt from state sales tax.
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 Spokane
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 Spokane
Two approvals, two bodies. The Spokane building department issues the electrical and structural permit. Avista Utilities issues permission to operate once the work is inspected and, where required, the meter is swapped. Nothing generates a single legal kWh until the second one lands, and the two queues do not move at the same speed.
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 Spokane
How much do solar panels cost in Spokane?
A 8 kW system in Spokane 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 Spokane?
Avista Utilities serves most of Spokane. It is investor-owned utility — regulated by the state public utility commission, so the statewide net metering or net billing rule below is the one that applies to you, and any change to it goes through a public docket you can read. 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.
Do I need Avista Utilities's permission to install solar in Spokane?
Yes, and it is separate from the building permit. Avista Utilities has to approve the interconnection application and then issue permission to operate after inspection. Until that lands, the system does not legally run. The Spokane building department handles the electrical and structural permit in parallel. A competent installer files both and can tell you the current turnaround on each without being asked.
Should I add a battery in Spokane?
It depends entirely on what Avista Utilities 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 Avista Utilities pay for solar you send back to the grid?
Avista Utilities is an investor-owned utility, so the Washington rule applies to it: Washington guarantees retail-rate net metering through at least 2029, and solar equipment is exempt from state sales tax. Ask for the specific rider name and the credit rate in writing before you sign — it is a tariff, and tariffs get refiled.
Where to look next
Incentives, electricity rates, net metering rules and the full Washington picture live on the state page: solar panels in Washington.