Wind Turbine Payback in Waukesha County, WI
Wind turbine payback in Waukesha 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 Waukesha County, WI averages 6.28 m/s (14 mph). A 10 kW turbine there would make about 21,781 kWh a year, worth $4,149 at WI's 19.05¢/kWh. Against an installed cost of about $100,000, that is a payback of 24 years, and the turbine is built to last about 20.
What to do in Waukesha County
A home turbine is not worth buying for savings in Waukesha County unless your spot is far windier than the county average, 6.9 m/s at the hub against 6.28 m/s here. Per kW, solar panels would make about 1,121 kWh a year here against the turbine's 2,178, so get a solar quote first.
What would have to change
- Power would have to cost 23¢/kWh, 1.2 times what WI pays now.
- Or the average wind at the hub would have to be 6.9 m/s instead of 6.28. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of WI
Waukesha County is the 498th 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 Waukesha County
January is the strongest month here, at 7.05 m/s and about 2,326 kWh. August is the weakest, 4.91 m/s and 1,014 kWh, so the best month makes 2.3 times the worst. November to March brings in 50% of the year's output in Waukesha County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 7.05 m/s | 2,326 kWh | $443 |
| February | 7.05 m/s | 2,101 kWh | $400 |
| March | 6.72 m/s | 2,122 kWh | $404 |
| April | 6.97 m/s | 2,203 kWh | $420 |
| May | 6.19 m/s | 1,796 kWh | $342 |
| June | 5.44 m/s | 1,283 kWh | $244 |
| July | 4.99 m/s | 1,060 kWh | $202 |
| August | 4.91 m/s | 1,014 kWh | $193 |
| September | 5.76 m/s | 1,476 kWh | $281 |
| October | 6.61 m/s | 2,055 kWh | $391 |
| November | 6.87 m/s | 2,145 kWh | $409 |
| December | 6.79 m/s | 2,167 kWh | $413 |
What a taller tower would buy
Measured at 10 m the wind in Waukesha County averages 4.98 m/s; at 50 m it is 6.99 m/s. That gives a shear exponent of 0.211, typical of ordinary open country. Going from 20 m to 50 m takes output from 17,941 to 26,971 kWh a year, 50% 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 | 5.76 m/s | 17,941 kWh | 29 years |
| 30 m | 6.28 m/s | 21,749 kWh | 24 years |
| 40 m | 6.67 m/s | 24,644 kWh | 21 years |
| 50 m | 6.99 m/s | 26,971 kWh | 20 years |
Counties around Waukesha County
2 of the 6 closest counties are windier at turbine height; the windiest, Racine County, averages 7.19 m/s.
- Milwaukee County, WI: 6.28 m/s, 21,781 kWh, payback 24 years (24 mi)
- Jefferson County, WI: 6.09 m/s, 20,371 kWh, payback 26 years (24 mi)
- Washington County, WI: 6.43 m/s, 22,891 kWh, payback 23 years (26 mi)
- Walworth County, WI: 6.05 m/s, 20,075 kWh, payback 26 years (27 mi)
- Racine County, WI: 7.19 m/s, 28,390 kWh, payback 19 years (32 mi)
- Dodge County, WI: 6.09 m/s, 20,371 kWh, payback 26 years (35 mi)
Sun versus wind in Waukesha County
Waukesha 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 2,178. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.9 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.