Wind Turbine Payback in Adams County, WA
Wind turbine payback in Adams 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 Adams County, WA averages 4.83 m/s (10.8 mph). A 10 kW turbine there would make about 11,407 kWh a year, worth $1,645 at WA's 14.42¢/kWh. Against an installed cost of about $100,000, that is a payback of 61 years, and the turbine is built to last about 20.
What to do in Adams County
A home turbine is not worth buying for savings in Adams County unless your spot is far windier than the county average, 8.1 m/s at the hub against 4.83 m/s here. Per kW, solar panels would make about 1,200 kWh a year here against the turbine's 1,141, so get a solar quote first.
What would have to change
- Power would have to cost 44¢/kWh, 3.0 times what WA pays now.
- Or the average wind at the hub would have to be 8.1 m/s instead of 4.83. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of WA
Adams County is the 1,542nd 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 Adams County
March is the strongest month here, at 5.48 m/s and about 1,348 kWh. August is the weakest, 4.17 m/s and 635 kWh, so the best month makes 2.1 times the worst. November to March brings in 49% of the year's output in Adams County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 5.02 m/s | 1,074 kWh | $155 |
| February | 5.10 m/s | 1,012 kWh | $146 |
| March | 5.48 m/s | 1,348 kWh | $194 |
| April | 5.10 m/s | 1,089 kWh | $157 |
| May | 4.61 m/s | 849 kWh | $122 |
| June | 4.62 m/s | 826 kWh | $119 |
| July | 4.26 m/s | 676 kWh | $97 |
| August | 4.17 m/s | 635 kWh | $92 |
| September | 4.50 m/s | 768 kWh | $111 |
| October | 4.91 m/s | 1,013 kWh | $146 |
| November | 5.23 m/s | 1,160 kWh | $167 |
| December | 5.01 m/s | 1,069 kWh | $154 |
What a taller tower would buy
Measured at 10 m the wind in Adams County averages 3.74 m/s; at 50 m it is 5.44 m/s. That gives a shear exponent of 0.233, typical of ordinary open country. Going from 20 m to 50 m takes output from 8,715 to 15,605 kWh a year, 79% 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 | 4.39 m/s | 8,715 kWh | 80 years |
| 30 m | 4.83 m/s | 11,404 kWh | 61 years |
| 40 m | 5.16 m/s | 13,659 kWh | 51 years |
| 50 m | 5.44 m/s | 15,605 kWh | 44 years |
Counties around Adams County
3 of the 6 closest counties are windier at turbine height; the windiest, Columbia County, averages 5.18 m/s.
- Franklin County, WA: 4.61 m/s, 10,008 kWh, payback 69 years (38 mi)
- Lincoln County, WA: 4.88 m/s, 11,734 kWh, payback 59 years (40 mi)
- Whitman County, WA: 4.84 m/s, 11,472 kWh, payback 61 years (47 mi)
- Grant County, WA: 4.55 m/s, 9,641 kWh, payback 72 years (47 mi)
- Walla Walla County, WA: 4.61 m/s, 10,008 kWh, payback 69 years (52 mi)
- Columbia County, WA: 5.18 m/s, 13,768 kWh, payback 50 years (57 mi)
Sun versus wind in Adams County
Adams 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 1,141. Kilowatt for kilowatt, panels make 1.1 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.