Wind Turbine Payback in Whitman County, WA
Wind turbine payback in Whitman 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 Whitman County, WA averages 4.84 m/s (10.8 mph). A 10 kW turbine there would make about 11,472 kWh a year, worth $1,654 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 Whitman County
A home turbine is not worth buying for savings in Whitman County unless your spot is far windier than the county average, 8.1 m/s at the hub against 4.84 m/s here. Per kW, solar panels would make about 1,168 kWh a year here against the turbine's 1,147, 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 4.84. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of WA
Whitman County is the 1,534th 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 Whitman County
March is the strongest month here, at 5.42 m/s and about 1,311 kWh. August is the weakest, 4.22 m/s and 657 kWh, so the best month makes 2.0 times the worst. November to March brings in 51% of the year's output in Whitman County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 5.28 m/s | 1,226 kWh | $177 |
| February | 5.07 m/s | 1,000 kWh | $144 |
| March | 5.42 m/s | 1,311 kWh | $189 |
| April | 5.08 m/s | 1,076 kWh | $155 |
| May | 4.48 m/s | 785 kWh | $113 |
| June | 4.55 m/s | 790 kWh | $114 |
| July | 4.26 m/s | 673 kWh | $97 |
| August | 4.22 m/s | 657 kWh | $95 |
| September | 4.44 m/s | 738 kWh | $106 |
| October | 4.89 m/s | 1,001 kWh | $144 |
| November | 5.27 m/s | 1,181 kWh | $170 |
| December | 5.14 m/s | 1,148 kWh | $166 |
What a taller tower would buy
Measured at 10 m the wind in Whitman County averages 3.67 m/s; at 50 m it is 5.51 m/s. That gives a shear exponent of 0.252, typical of ordinary open country. Going from 20 m to 50 m takes output from 8,597 to 16,109 kWh a year, 87% 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 | 4.37 m/s | 8,597 kWh | 81 years |
| 30 m | 4.84 m/s | 11,501 kWh | 60 years |
| 40 m | 5.21 m/s | 13,967 kWh | 50 years |
| 50 m | 5.51 m/s | 16,109 kWh | 43 years |
Counties around Whitman County
2 of the 6 closest counties are windier at turbine height; the windiest, Columbia County, averages 5.18 m/s.
- Garfield County, WA: 4.91 m/s, 11,933 kWh, payback 58 years (33 mi)
- Latah County, ID: 3.61 m/s, 4,778 kWh, payback over 100 years (38 mi)
- Columbia County, WA: 5.18 m/s, 13,768 kWh, payback 50 years (46 mi)
- Adams County, WA: 4.83 m/s, 11,407 kWh, payback 61 years (47 mi)
- Benewah County, ID: 3.61 m/s, 4,778 kWh, payback over 100 years (48 mi)
- Spokane County, WA: 4.42 m/s, 8,865 kWh, payback 78 years (50 mi)
Sun versus wind in Whitman County
Whitman County gets 4 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,168 kWh a year; one kW of the turbine above makes 1,147. Kilowatt for kilowatt, panels make 1.0 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.