Wind Turbine Payback in Jefferson County, WI
Wind turbine payback in Jefferson 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 Jefferson County, WI averages 6.09 m/s (13.6 mph). A 10 kW turbine there would make about 20,371 kWh a year, worth $3,881 at WI's 19.05¢/kWh. Against an installed cost of about $100,000, that is a payback of 26 years, and the turbine is built to last about 20.
What to do in Jefferson County
A home turbine is not worth buying for savings in Jefferson County unless your spot is far windier than the county average, 6.9 m/s at the hub against 6.09 m/s here. Per kW, solar panels would make about 1,121 kWh a year here against the turbine's 2,037, 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 6.09. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of WI
Jefferson County is the 701st 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 Jefferson County
April is the strongest month here, at 6.91 m/s and about 2,170 kWh. August is the weakest, 4.80 m/s and 954 kWh, so the best month makes 2.3 times the worst. November to March brings in 49% of the year's output in Jefferson County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.68 m/s | 2,099 kWh | $400 |
| February | 6.77 m/s | 1,946 kWh | $371 |
| March | 6.56 m/s | 2,027 kWh | $386 |
| April | 6.91 m/s | 2,170 kWh | $413 |
| May | 6.11 m/s | 1,741 kWh | $332 |
| June | 5.39 m/s | 1,255 kWh | $239 |
| July | 4.91 m/s | 1,014 kWh | $193 |
| August | 4.80 m/s | 954 kWh | $182 |
| September | 5.64 m/s | 1,403 kWh | $267 |
| October | 6.39 m/s | 1,921 kWh | $366 |
| November | 6.57 m/s | 1,967 kWh | $375 |
| December | 6.42 m/s | 1,937 kWh | $369 |
What a taller tower would buy
Measured at 10 m the wind in Jefferson County averages 4.77 m/s; at 50 m it is 6.82 m/s. That gives a shear exponent of 0.222, typical of ordinary open country. Going from 20 m to 50 m takes output from 16,505 to 25,747 kWh a year, 56% 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 | 5.56 m/s | 16,505 kWh | 32 years |
| 30 m | 6.09 m/s | 20,363 kWh | 26 years |
| 40 m | 6.49 m/s | 23,336 kWh | 23 years |
| 50 m | 6.82 m/s | 25,747 kWh | 20 years |
Counties around Jefferson County
2 of the 6 closest counties are windier at turbine height; the windiest, Washington County, averages 6.43 m/s.
- Waukesha County, WI: 6.28 m/s, 21,781 kWh, payback 24 years (24 mi)
- Walworth County, WI: 6.05 m/s, 20,075 kWh, payback 26 years (27 mi)
- Rock County, WI: 5.98 m/s, 19,556 kWh, payback 27 years (28 mi)
- Dodge County, WI: 6.09 m/s, 20,371 kWh, payback 26 years (29 mi)
- Dane County, WI: 6.08 m/s, 20,297 kWh, payback 26 years (33 mi)
- Washington County, WI: 6.43 m/s, 22,891 kWh, payback 23 years (38 mi)
Sun versus wind in Jefferson County
Jefferson County gets 3.84 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,121 kWh a year; one kW of the turbine above makes 2,037. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.8 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.