Wind Turbine Payback in Benton County, WA
Wind turbine payback in Benton 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 Benton 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 Benton County
A home turbine is not worth buying for savings in Benton 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 1,232 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
Benton 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 Benton County
March is the strongest month here, at 5.28 m/s and about 1,226 kWh. September is the weakest, 4.42 m/s and 729 kWh, so the best month makes 1.7 times the worst. November to March brings in 45% of the year's output in Benton County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 4.93 m/s | 1,024 kWh | $148 |
| February | 4.90 m/s | 911 kWh | $131 |
| March | 5.28 m/s | 1,226 kWh | $177 |
| April | 5.09 m/s | 1,080 kWh | $156 |
| May | 4.71 m/s | 906 kWh | $131 |
| June | 4.92 m/s | 986 kWh | $142 |
| July | 4.68 m/s | 887 kWh | $128 |
| August | 4.50 m/s | 794 kWh | $114 |
| September | 4.42 m/s | 729 kWh | $105 |
| October | 4.76 m/s | 930 kWh | $134 |
| November | 5.00 m/s | 1,030 kWh | $149 |
| December | 4.92 m/s | 1,019 kWh | $147 |
What a taller tower would buy
Measured at 10 m the wind in Benton County averages 3.76 m/s; at 50 m it is 5.44 m/s. That gives a shear exponent of 0.229, typical of ordinary open country. Going from 20 m to 50 m takes output from 8,808 to 15,605 kWh a year, 77% 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 | 4.41 m/s | 8,808 kWh | 79 years |
| 30 m | 4.84 m/s | 11,468 kWh | 61 years |
| 40 m | 5.17 m/s | 13,691 kWh | 51 years |
| 50 m | 5.44 m/s | 15,605 kWh | 44 years |
Counties around Benton County
3 of the 6 closest counties are windier at turbine height; the windiest, Morrow County, averages 5.25 m/s.
- Franklin County, WA: 4.61 m/s, 10,008 kWh, payback 69 years (36 mi)
- Walla Walla County, WA: 4.61 m/s, 10,008 kWh, payback 69 years (50 mi)
- Morrow County, OR: 5.25 m/s, 14,256 kWh, payback 45 years (56 mi)
- Umatilla County, OR: 5.02 m/s, 12,670 kWh, payback 51 years (58 mi)
- Yakima County, WA: 4.03 m/s, 6,729 kWh, payback over 100 years (60 mi)
- Klickitat County, WA: 4.88 m/s, 11,734 kWh, payback 59 years (65 mi)
Sun versus wind in Benton County
Benton County gets 4.22 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,232 kWh a year; one kW of the turbine above makes 1,147. 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.