Wind Turbine Payback in Trempealeau County, WI
Wind turbine payback in Trempealeau 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 Trempealeau County, WI averages 6 m/s (13.4 mph). A 10 kW turbine there would make about 19,704 kWh a year, worth $3,754 at WI's 19.05¢/kWh. Against an installed cost of about $100,000, that is a payback of 27 years, and the turbine is built to last about 20.
What to do in Trempealeau County
A home turbine is not worth buying for savings in Trempealeau County unless your spot is far windier than the county average, 6.9 m/s at the hub against 6 m/s here. Per kW, solar panels would make about 1,127 kWh a year here against the turbine's 1,970, so get a solar quote first.
What would have to change
- Power would have to cost 25¢/kWh, 1.3 times what WI pays now.
- Or the average wind at the hub would have to be 6.9 m/s instead of 6. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of WI
Trempealeau County is the 840th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in WI is Manitowoc County at 7.32 m/s, payback 18 years.
Month by month in Trempealeau County
April is the strongest month here, at 6.71 m/s and about 2,050 kWh. August is the weakest, 4.99 m/s and 1,059 kWh, so the best month makes 1.9 times the worst. November to March brings in 46% of the year's output in Trempealeau County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.35 m/s | 1,896 kWh | $361 |
| February | 6.53 m/s | 1,813 kWh | $345 |
| March | 6.37 m/s | 1,907 kWh | $363 |
| April | 6.71 m/s | 2,050 kWh | $391 |
| May | 6.09 m/s | 1,727 kWh | $329 |
| June | 5.56 m/s | 1,354 kWh | $258 |
| July | 4.99 m/s | 1,059 kWh | $202 |
| August | 4.99 m/s | 1,059 kWh | $202 |
| September | 5.83 m/s | 1,514 kWh | $288 |
| October | 6.29 m/s | 1,856 kWh | $354 |
| November | 6.25 m/s | 1,769 kWh | $337 |
| December | 6.05 m/s | 1,705 kWh | $325 |
What a taller tower would buy
Measured at 10 m the wind in Trempealeau County averages 4.68 m/s; at 50 m it is 6.73 m/s. That gives a shear exponent of 0.226, typical of ordinary open country. Going from 20 m to 50 m takes output from 15,829 to 25,093 kWh a year, 59% 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 | 5.47 m/s | 15,829 kWh | 33 years |
| 30 m | 6 m/s | 19,676 kWh | 27 years |
| 40 m | 6.4 m/s | 22,662 kWh | 23 years |
| 50 m | 6.73 m/s | 25,093 kWh | 21 years |
Counties around Trempealeau County
5 of the 6 closest counties are windier at turbine height; the windiest, Winona County, averages 6.17 m/s.
- Buffalo County, WI: 6.03 m/s, 19,926 kWh, payback 26 years (21 mi)
- Jackson County, WI: 6.02 m/s, 19,852 kWh, payback 26 years (28 mi)
- Eau Claire County, WI: 6 m/s, 19,704 kWh, payback 27 years (29 mi)
- La Crosse County, WI: 6.03 m/s, 19,926 kWh, payback 26 years (30 mi)
- Winona County, MN: 6.17 m/s, 20,965 kWh, payback 29 years (30 mi)
- Pepin County, WI: 6.03 m/s, 19,926 kWh, payback 26 years (32 mi)
Sun versus wind in Trempealeau County
Trempealeau County gets 3.86 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,127 kWh a year; one kW of the turbine above makes 1,970. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.7 times. 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.