A worked example: 8 kW in Spokane
An 8 kW system — about 19 × 425-watt panels — at Spokane's assumed installed cost of $2.60–$3.40 per watt runs roughly $20,800–$27,200 before incentives. At about 1,200 kWh per installed kW, it would generate around 9,600 kWh per year. Valuing self-consumed electricity at the assumed $0.11/kWh retail rate and exports conservatively, first-year savings land near $870 — a simple payback of roughly 24–31 years.
No federal tax credit is included: the Section 25D residential credit ended for systems installed after December 31, 2025.
Average cost of solar panels in Spokane by system size
At the Spokane market rate of $2.60–$3.40 per watt, using the local production factor rather than the Washington average:
| System size | Panels | Installed cost | Annual production | Est. payback |
|---|---|---|---|---|
| 6 kW | 15 | $15,600–$20,400 | 7,200 kWh | 24–31 yrs |
| 8 kW | 19 | $20,800–$27,200 | 9,600 kWh | 24–31 yrs |
| 10 kW | 24 | $26,000–$34,000 | 12,000 kWh | 24–31 yrs |
| 12 kW | 29 | $31,200–$40,800 | 14,400 kWh | 24–31 yrs |
Over a 25-year life, solar electricity in Spokane comes to roughly 9.2¢–12.0¢ per kilowatt-hour, against a local retail rate assumed at 11.0¢.
How Spokane differs from the Washington average
Statewide averages blend climates, utilities and installer markets that can differ sharply within a single state — which is why a Spokane estimate is not simply the Washington number.
| Assumption | Spokane | Washington average |
|---|---|---|
| Electricity rate | $0.11/kWh | $0.12/kWh |
| Production (kWh/kW/yr) | 1,200 | 1,050 |
| Installed cost per watt | $2.60–$3.40 | $2.60–$3.40 |
| 8 kW system cost | $20,800–$27,200 | $20,800–$27,200 |
| Estimated payback | 24–31 yrs | 25–33 yrs |
Avista and solar exports
Avista offers retail-rate net metering with credits that roll over monthly and zero out each March. Avista's residential rates are among the lowest in the country, which is the central fact of solar economics in Spokane.
Statewide, washington requires retail-rate net metering with annual true-up (credits zeroed each spring) for systems up to 100 kW at most utilities.
Local factors that change a Spokane solar quote
Washington exempts qualifying residential solar from sales tax, which is worth real money in a state with no income tax and a high sales tax rate. Snow load matters in Spokane in a way it does not elsewhere in Washington — racking must be rated for it, and winter snow cover costs some production.
Beyond location, equipment, roof condition, electrical upgrades, permitting, labor, system size, batteries and financing all move the installed price.
Solar incentives available in Spokane
Washington exempts qualifying residential solar systems from sales tax — significant given the rate — but offers no current state production incentive for new customers.
There is no federal residential credit for systems installed in 2026, so state, local and utility programs are now the entire incentive picture for a purchased system. See the full Washington solar incentives guide.
Frequently asked questions
What is the average cost of solar panels in Spokane?
Averaging the Spokane market at $2.60–$3.40 per watt installed, a 6 kW system runs $15,600–$20,400, an 8 kW $20,800–$27,200, and a 10 kW $26,000–$34,000, all before incentives. Over a 25-year life that is roughly 9.2¢–12.0¢ per kilowatt-hour, against a local retail rate assumed at 11.0¢.
How much does it cost to install solar panels in Spokane?
The per-watt figures above are turnkey: panels, inverter, racking, labor, permitting and interconnection. What moves a Spokane quote away from them is local: Washington exempts qualifying residential solar from sales tax, which is worth real money in a state with no income tax and a high sales tax rate. Snow load matters in Spokane in a way it does not elsewhere in Washington — racking must be rated for it, and winter snow cover costs some production. Roof complexity and a main-panel upgrade are the other two big swings, and only a site visit settles either.
How much do solar panels cost in Spokane, WA?
At an assumed installed cost of $2.60–$3.40 per watt for the Spokane market, a typical 8 kW home system runs roughly $20,800–$27,200 before incentives — about 19 panels at 425 watts each. That is in line with the Washington statewide assumption, reflecting local installer competition.
How much electricity does a solar system produce in Spokane?
We assume about 1,200 kWh per installed kW per year in Spokane — so an 8 kW system generates roughly 9,600 kWh annually. That is 14% above the Washington average, because statewide figures blend climates that can differ sharply within one state.
Is solar worth it in Spokane?
With electricity around $0.11/kWh and 1,200 kWh/kW of annual production, an 8 kW system in Spokane could save roughly $870 in year one — a simple payback of about 24–31 years with no federal tax credit. Whether that clears your bar depends on your rate plan, how much of the output you use on site, your roof, and how long you plan to stay.
Who is the electric utility in Spokane and how does it pay for solar exports?
Avista. Avista offers retail-rate net metering with credits that roll over monthly and zero out each March. Avista's residential rates are among the lowest in the country, which is the central fact of solar economics in Spokane.
Is there still a federal solar tax credit in Spokane?
No — the 30% federal residential clean energy credit (Section 25D) ended for systems installed after December 31, 2025 under the One Big Beautiful Bill Act. None of the figures on this page include it. Leased or PPA systems may still benefit indirectly, because the system owner can claim the commercial 48E credit through 2027.
Use this as a starting point
These are broad local assumptions, not a market survey of Spokane installers or a binding quote. Before purchasing, verify applicable incentives, your specific utility tariff, installer licensing, warranties and financing terms.
Where these numbers come from
Local assumptions are informed by public data and reviewed periodically (September 2026):