Wind Turbine Payback in Snohomish County, WA
Wind turbine payback in Snohomish County
No. The turbine wears out before it pays for itself.
At 30 m, the height a home turbine tower usually reaches, the wind in Snohomish County, WA averages 2.49 m/s (5.6 mph). A 10 kW turbine there would make about 1,330 kWh a year, worth $192 at WA's 14.42¢/kWh. Against an installed cost of about $100,000, that is a payback of over 100 years, and the turbine is built to last about 20.
What to do in Snohomish County
A home turbine is not worth buying for savings in Snohomish County unless your spot is far windier than the county average, 8.1 m/s at the hub against 2.49 m/s here. Per kW, solar panels would make about 1,025 kWh a year here against the turbine's 133, so get a solar quote first.
What would have to change
- Power would have to cost 376¢/kWh, 26.1 times what WA pays now.
- Or the average wind at the hub would have to be 8.1 m/s instead of 2.49. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of WA
Snohomish County is the 3,139th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in WA is Columbia County at 5.18 m/s, payback 50 years.
Month by month in Snohomish County
January is the strongest month here, at 3.38 m/s and about 329 kWh. August is the weakest, 1.62 m/s and 14 kWh, so the best month makes 23.5 times the worst. November to March brings in 78% of the year's output in Snohomish County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.38 m/s | 329 kWh | $47 |
| February | 2.98 m/s | 194 kWh | $28 |
| March | 2.92 m/s | 201 kWh | $29 |
| April | 2.44 m/s | 100 kWh | $14 |
| May | 2.00 m/s | 45 kWh | $6 |
| June | 1.83 m/s | 28 kWh | $4 |
| July | 1.61 m/s | 14 kWh | $2 |
| August | 1.62 m/s | 14 kWh | $2 |
| September | 1.98 m/s | 41 kWh | $6 |
| October | 2.57 m/s | 127 kWh | $18 |
| November | 3.19 m/s | 263 kWh | $38 |
| December | 3.32 m/s | 311 kWh | $45 |
What a taller tower would buy
Measured at 10 m the wind in Snohomish County averages 1.67 m/s; at 50 m it is 2.99 m/s. That gives a shear exponent of 0.362, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 725 to 2,571 kWh a year, 255% more, before counting the extra cost of the taller tower. Why tower height decides it explains the shear behind these numbers.
| Hub height | Average wind | Output | Payback |
|---|---|---|---|
| 20 m | 2.15 m/s | 725 kWh | over 100 years |
| 30 m | 2.49 m/s | 1,320 kWh | over 100 years |
| 40 m | 2.76 m/s | 1,940 kWh | over 100 years |
| 50 m | 2.99 m/s | 2,571 kWh | over 100 years |
Counties around Snohomish County
4 of the 6 closest counties are windier at turbine height; the windiest, Kitsap County, averages 2.97 m/s.
- Skagit County, WA: 2.34 m/s, 1,043 kWh, payback over 100 years (30 mi)
- King County, WA: 2.75 m/s, 1,920 kWh, payback over 100 years (39 mi)
- Island County, WA: 2.56 m/s, 1,477 kWh, payback over 100 years (42 mi)
- Kitsap County, WA: 2.97 m/s, 2,513 kWh, payback over 100 years (50 mi)
- Whatcom County, WA: 2.31 m/s, 989 kWh, payback over 100 years (55 mi)
- Chelan County, WA: 2.51 m/s, 1,371 kWh, payback over 100 years (55 mi)
Sun versus wind in Snohomish County
Snohomish County gets 3.51 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,025 kWh a year; one kW of the turbine above makes 133. Kilowatt for kilowatt, panels make 7.7 times as much here as the turbine. Panel output assumes an 80% system performance ratio. Wind or solar runs the same comparison for every county.
How this is worked out
Wind is NASA's Power climate record, the 2001-2025 average at 10 m and 50 m for the county's centre, carried to 30 m with this county's own measured wind shear and spread into hours with a Rayleigh distribution. The turbine is a generic 10 kW, 7 m rotor machine with 10% losses. Cost is $10,000 per kW installed with no tax credit, because the federal one ended in 2025. One county-centre number cannot see your hilltop or your tree line, so treat it as the starting point for a site survey, not a substitute. The full method and its weak spots are in how the numbers are made.