Solar panels in Seattle, WA
Roofs in Seattle get about 1,262 hours of usable sunlight a year — less than 97% of the cities we've measured. Here's what that means in cost, savings and payback, using real rooftop data rather than a national average.
Check your specific roof in Seattle → City averages are a starting point; your own roof's size, pitch and shading change the answer a lot.
What a typical Seattle solar system costs
A 26-panel system (10.4 kW) is about right for an average Seattle home using 10,800 kWh a year. It would produce roughly 11,156 kWh annually and offset 100% of that usage.
| System | Size | kWh/yr | Net cost | Saves/yr | Payback |
|---|---|---|---|---|---|
| 8 panels | 3.2 kW | 3,433 | $6,384 | $388 | 16.5 yrs |
| 12 panels | 4.8 kW | 5,149 | $9,576 | $582 | 16.5 yrs |
| 16 panels | 6.4 kW | 6,865 | $12,768 | $776 | 16.5 yrs |
| 20 panels | 8 kW | 8,582 | $15,960 | $970 | 16.5 yrs |
| 26 panels | 10.4 kW | 11,156 | $20,748 | $1,230 | 16.9 yrs |
Notice that payback barely improves as systems get bigger, and eventually gets worse. That's because you can only save money on electricity you were going to buy anyway. Once a system covers your usage, extra panels mostly generate exports at a much lower rate.
Why Seattle gets 1,262 sun hours
That figure comes from Google's analysis of real rooftops across Seattle — it already accounts for shading from trees, chimneys and neighbouring buildings, which is why it's lower than the raw "hours of daylight" figures you'll see elsewhere. An unusually open, unshaded roof in Seattle reaches about 1,295 hours, roughly 3% better than typical.
The numbers behind this page
| Typical usable sunlight | 1,262 hrs/yr |
|---|---|
| Unshaded roof | 1,295 hrs/yr |
| Electricity rate (Washington avg) | 11.3¢/kWh |
| Installed cost assumed | $2.85/W |
| Panel size assumed | 400 W |
| Federal tax credit | 30% |
| Typical household usage | 10,800 kWh/yr |
| Power used as generated | 34% |
| Paid for exported power | full retail (net metering) |
| Rooftops sampled here | 9 |
| Google imagery from | 2024 |
Nearby cities
See all of Washington → statewide sunlight, rates, incentives and every city we've measured.
Seattle solar questions
How many solar panels do I need in Seattle?
About 26 panels for an average home. Seattle roofs get 1,262 usable sun hours a year, so each 400W panel produces roughly 429 kWh annually.
Is solar worth it in Seattle?
At 11.3¢/kWh and 1,262 sun hours, a typical system pays for itself in about 16.9 years and returns roughly $10,013 over 25 years. That is slower than the national average, so compare quotes carefully.
How much do solar panels cost in Seattle?
A 10.4 kW system costs about $29,640 before incentives and $20,748 after the 30% federal tax credit. Prices vary by installer, roof complexity and equipment.
Worth reading before you buy
Estimates only, generated 2026-08-22 from Google Solar API rooftop samples and average Washington electricity rates. Not a quote and not financial advice. Your roof, usage, utility plan and local incentives will change these numbers — get real quotes before buying.