Solar panels in Spokane, WA: payback and output
A kW of south-facing panels in Spokane produces about 1,257 kWh a year, 15% more than Seattle, the Washington reference city. Summer months produce 3.3× what winter does. To cover a typical 10,500 kWh/yr home on paper you'd need roughly 8.4 kW.
Output by month in Spokane (kWh per kW)
Best: Jul · weakest: Dec.
Example 7 kW system in Spokane
- Installed cost (example)
- $21,000
- Production, year 1
- 8,796 kWh
- Savings, year 1
- $1,294
- Payback
- 15.1 years
- 25-year net gain
- $17,879
Uses the Washington average price (14.71¢/kWh, EIA July 2026), full net metering and no incentives. Your utility's rate and export credit may differ — change them below.
Roof direction in Spokane
Yearly output per kW of panels at a 20° pitch, and how it compares with a south-facing roof.
| Roof faces | kWh per kW/yr | vs. south |
|---|---|---|
| South | 1,257 | — |
| Southeast | 1,191 | −5% |
| Southwest | 1,216 | −3% |
| East | 1,052 | −16% |
| West | 1,087 | −14% |
| East-west (split) | 1,069 | −15% |
Calculate your home in Spokane
Estimated payback
15.1 years
A slow payback: size, price and export credit matter a lot here.
≈ $108/month off your bill in year 1
- Year-1 savings
- $1,294
- 25-yr net gain
- $17,879
- Return (IRR)
- 4.9%
- Net cost
- $21,000
Cumulative savings minus cost
Production vs. use by month
8,796 kWh/yr
Covers 38% of your use directly; 46% of the output is used on the spot.
Which size pays off best?
Same usage and prices, only size changes. Best 25-year gain: 8 kW.
| Size | Cost | Year-1 savings | Payback | 25-yr gain |
|---|---|---|---|---|
| 3 kW | $9,000 | $555 | 16.4 years | $6,234 |
| 4 kW | $12,000 | $739 | 15.8 years | $9,145 |
| 5 kW | $15,000 | $924 | 15.5 years | $12,056 |
| 6 kW | $18,000 | $1,109 | 15.2 years | $14,967 |
| 7 kW | $21,000 | $1,294 | 15.1 years | $17,879 |
| 8 kW | $24,000 | $1,479 | 15.0 years | $20,790 |
| 10 kW | $30,000 | $1,545 | 16.8 years | $20,258 |
| 12 kW | $36,000 | $1,545 | 19.4 years | $14,258 |
Read the full Washington solar guide for net metering, orientation and price trends.
Other cities in Washington
Cities with similar sunshine
Solar in Spokane: common questions
Are solar panels worth it in Spokane, WA?
For an example 7 kW system costing $21,000 on a home using 10,500 kWh a year, payback in Spokane is 15.1 years with full net metering and 19.9 years if exports earn half the retail rate, at the Washington average price of 14.71¢/kWh (EIA, July 2026).
How much electricity do solar panels produce in Spokane?
About 1,257 kWh per year for each kW of south-facing panels at a 20° pitch (NLR PVWatts, typical-year weather), from 39 kWh in Dec to 177 kWh in Jul.
What size solar system does a home in Spokane need?
About 8.4 kW to cover 10,500 kWh a year. Divide your own annual use by 1,257 kWh per kW for a first estimate; if exports earn less than retail, a smaller system often pays back faster.
Does roof direction matter in Spokane?
Yes. Per kW at a 20° pitch: south 1,257 kWh, southeast 1,191 kWh, southwest 1,216 kWh, east 1,052 kWh, west 1,087 kWh, east-west (split) 1,069 kWh a year. South-facing roofs produce the most; east or west roofs still work, with less output.
Guides for going solar in Spokane
- Payback · 4 minIs solar still worth it without the 30% federal tax credit?The 30% federal solar credit is gone for new systems. We ran payback for every state without it, and compared it with what the credit used to do.
- Planning · 3 minHow many solar panels do I need? Sizing from your electric billA step-by-step way to size a home solar system from your annual kWh, daytime use and local sunshine, with real size-vs-payback tables for four states.
- Payback · 4 minNet metering vs. net billing: how export credits change paybackHow much your utility pays for exported solar power can add years to payback. We compare full, half and quarter-retail credits in every state.
- Planning · 6 minEast- or West-Facing Roof: Is Solar Still Worth It?East- or west-facing solar panels made about 14.5% to 14.8% less power than south-facing ones across U.S. states. See where the loss is biggest and smallest.
- Planning · 6 minSolar Panels in Winter: Output by State vs. SummerHow much do solar panels make in winter? Winter vs. summer output per kW for U.S. states, why the gap grows up north, and what it means for net metering.
- Payback · 5 minRising electricity prices: where solar pays back fastestCompare electricity prices and solar payback by state: see where a rooftop system pays back fastest, where it is slowest, and why credit rules matter.
Data: NLR PVWatts v8 (U.S. DOE National Laboratory of the Rockies, formerly NREL), TMY weather near Spokane (47.66, -117.43), 14% losses, retrieved 2026-10-11. Published 2026-10-15.