Wind Turbine Payback in Dane County, WI
Wind turbine payback in Dane 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 Dane County, WI averages 6.08 m/s (13.6 mph). A 10 kW turbine there would make about 20,297 kWh a year, worth $3,867 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 Dane County
A home turbine is not worth buying for savings in Dane County unless your spot is far windier than the county average, 6.9 m/s at the hub against 6.08 m/s here. Per kW, solar panels would make about 1,124 kWh a year here against the turbine's 2,030, 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 6.08. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of WI
Dane County is the 714th 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 Dane County
April is the strongest month here, at 6.89 m/s and about 2,158 kWh. August is the weakest, 4.78 m/s and 942 kWh, so the best month makes 2.3 times the worst. November to March brings in 49% of the year's output in Dane County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.65 m/s | 2,081 kWh | $396 |
| February | 6.74 m/s | 1,930 kWh | $368 |
| March | 6.55 m/s | 2,020 kWh | $385 |
| April | 6.89 m/s | 2,158 kWh | $411 |
| May | 6.10 m/s | 1,733 kWh | $330 |
| June | 5.40 m/s | 1,258 kWh | $240 |
| July | 4.89 m/s | 1,001 kWh | $191 |
| August | 4.78 m/s | 942 kWh | $179 |
| September | 5.66 m/s | 1,412 kWh | $269 |
| October | 6.39 m/s | 1,919 kWh | $366 |
| November | 6.53 m/s | 1,944 kWh | $370 |
| December | 6.37 m/s | 1,908 kWh | $363 |
What a taller tower would buy
Measured at 10 m the wind in Dane County averages 4.77 m/s; at 50 m it is 6.8 m/s. That gives a shear exponent of 0.220, typical of ordinary open country. Going from 20 m to 50 m takes output from 16,461 to 25,602 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 | 16,461 kWh | 32 years |
| 30 m | 6.08 m/s | 20,276 kWh | 26 years |
| 40 m | 6.47 m/s | 23,217 kWh | 23 years |
| 50 m | 6.8 m/s | 25,602 kWh | 21 years |
Counties around Dane County
1 of the 6 closest counties is windier at turbine height; the windiest, Jefferson County, averages 6.09 m/s.
- Columbia County, WI: 6.06 m/s, 20,149 kWh, payback 26 years (28 mi)
- Green County, WI: 5.98 m/s, 19,556 kWh, payback 27 years (29 mi)
- Rock County, WI: 5.98 m/s, 19,556 kWh, payback 27 years (32 mi)
- Jefferson County, WI: 6.09 m/s, 20,371 kWh, payback 26 years (33 mi)
- Sauk County, WI: 6.07 m/s, 20,223 kWh, payback 26 years (36 mi)
- Iowa County, WI: 6.01 m/s, 19,778 kWh, payback 27 years (36 mi)
Sun versus wind in Dane County
Dane County gets 3.85 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,124 kWh a year; one kW of the turbine above makes 2,030. 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.