Wind Turbine Payback in Douglas County, WA
Wind turbine payback in Douglas 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 Douglas County, WA averages 3.61 m/s (8.1 mph). A 10 kW turbine there would make about 4,778 kWh a year, worth $689 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 Douglas County
A home turbine is not worth buying for savings in Douglas County unless your spot is far windier than the county average, 8.1 m/s at the hub against 3.61 m/s here. Per kW, solar panels would make about 1,200 kWh a year here against the turbine's 478, so get a solar quote first.
What would have to change
- Power would have to cost 105¢/kWh, 7.3 times what WA pays now.
- Or the average wind at the hub would have to be 8.1 m/s instead of 3.61. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of WA
Douglas County is the 2,382nd 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 Douglas County
April is the strongest month here, at 3.92 m/s and about 508 kWh. December is the weakest, 3.22 m/s and 279 kWh, so the best month makes 1.8 times the worst. November to March brings in 36% of the year's output in Douglas County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.22 m/s | 281 kWh | $41 |
| February | 3.55 m/s | 348 kWh | $50 |
| March | 3.88 m/s | 507 kWh | $73 |
| April | 3.92 m/s | 508 kWh | $73 |
| May | 3.75 m/s | 459 kWh | $66 |
| June | 3.89 m/s | 498 kWh | $72 |
| July | 3.84 m/s | 493 kWh | $71 |
| August | 3.67 m/s | 426 kWh | $61 |
| September | 3.54 m/s | 370 kWh | $53 |
| October | 3.52 m/s | 373 kWh | $54 |
| November | 3.39 m/s | 322 kWh | $46 |
| December | 3.22 m/s | 279 kWh | $40 |
What a taller tower would buy
Measured at 10 m the wind in Douglas County averages 2.75 m/s; at 50 m it is 4.1 m/s. That gives a shear exponent of 0.248, typical of ordinary open country. Going from 20 m to 50 m takes output from 3,459 to 7,090 kWh a year, 105% 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 | 3.27 m/s | 3,459 kWh | over 100 years |
| 30 m | 3.61 m/s | 4,787 kWh | over 100 years |
| 40 m | 3.88 m/s | 5,986 kWh | over 100 years |
| 50 m | 4.1 m/s | 7,090 kWh | 98 years |
Counties around Douglas County
2 of the 6 closest counties are windier at turbine height; the windiest, Lincoln County, averages 4.88 m/s.
- Grant County, WA: 4.55 m/s, 9,641 kWh, payback 72 years (38 mi)
- Chelan County, WA: 2.51 m/s, 1,371 kWh, payback over 100 years (44 mi)
- Okanogan County, WA: 2.7 m/s, 1,797 kWh, payback over 100 years (56 mi)
- Lincoln County, WA: 4.88 m/s, 11,734 kWh, payback 59 years (60 mi)
- Kittitas County, WA: 3.56 m/s, 4,570 kWh, payback over 100 years (63 mi)
- Ferry County, WA: 2.74 m/s, 1,895 kWh, payback over 100 years (74 mi)
Sun versus wind in Douglas County
Douglas County gets 4.11 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,200 kWh a year; one kW of the turbine above makes 478. Kilowatt for kilowatt, panels make 2.5 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.