Wind Turbine Payback in Portage County, WI
Wind turbine payback in Portage 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 Portage County, WI averages 6.07 m/s (13.6 mph). A 10 kW turbine there would make about 20,223 kWh a year, worth $3,852 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 Portage County
A home turbine is not worth buying for savings in Portage County unless your spot is far windier than the county average, 6.9 m/s at the hub against 6.07 m/s here. Per kW, solar panels would make about 1,115 kWh a year here against the turbine's 2,022, 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 6.07. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of WI
Portage County is the 717th 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 Portage County
April is the strongest month here, at 6.79 m/s and about 2,095 kWh. August is the weakest, 4.98 m/s and 1,054 kWh, so the best month makes 2.0 times the worst. November to March brings in 48% of the year's output in Portage County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.59 m/s | 2,043 kWh | $389 |
| February | 6.79 m/s | 1,956 kWh | $373 |
| March | 6.48 m/s | 1,977 kWh | $377 |
| April | 6.79 m/s | 2,095 kWh | $399 |
| May | 6.09 m/s | 1,729 kWh | $329 |
| June | 5.46 m/s | 1,297 kWh | $247 |
| July | 5.02 m/s | 1,075 kWh | $205 |
| August | 4.98 m/s | 1,054 kWh | $201 |
| September | 5.72 m/s | 1,451 kWh | $276 |
| October | 6.37 m/s | 1,909 kWh | $364 |
| November | 6.31 m/s | 1,810 kWh | $345 |
| December | 6.29 m/s | 1,859 kWh | $354 |
What a taller tower would buy
Measured at 10 m the wind in Portage County averages 4.76 m/s; at 50 m it is 6.8 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 16,387 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 | 5.55 m/s | 16,387 kWh | 32 years |
| 30 m | 6.07 m/s | 20,230 kWh | 26 years |
| 40 m | 6.47 m/s | 23,196 kWh | 23 years |
| 50 m | 6.8 m/s | 25,602 kWh | 21 years |
Counties around Portage County
1 of the 6 closest counties is windier at turbine height; the windiest, Adams County, averages 6.11 m/s.
- Waupaca County, WI: 6.01 m/s, 19,778 kWh, payback 27 years (26 mi)
- Wood County, WI: 6.06 m/s, 20,149 kWh, payback 26 years (27 mi)
- Waushara County, WI: 6.06 m/s, 20,149 kWh, payback 26 years (28 mi)
- Marathon County, WI: 6.02 m/s, 19,852 kWh, payback 26 years (32 mi)
- Adams County, WI: 6.11 m/s, 20,520 kWh, payback 26 years (37 mi)
- Shawano County, WI: 5.94 m/s, 19,260 kWh, payback 27 years (42 mi)
Sun versus wind in Portage County
Portage County gets 3.82 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,115 kWh a year; one kW of the turbine above makes 2,022. 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.