Wind Turbine Payback in Forest County, WI
Wind turbine payback in Forest 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 Forest County, WI averages 4.98 m/s (11.1 mph). A 10 kW turbine there would make about 12,400 kWh a year, worth $2,362 at WI's 19.05¢/kWh. Against an installed cost of about $100,000, that is a payback of 42 years, and the turbine is built to last about 20.
What to do in Forest County
A home turbine is not worth buying for savings in Forest County unless your spot is far windier than the county average, 6.9 m/s at the hub against 4.98 m/s here. Per kW, solar panels would make about 1,080 kWh a year here against the turbine's 1,240, so get a solar quote first.
What would have to change
- Power would have to cost 40¢/kWh, 2.1 times what WI pays now.
- Or the average wind at the hub would have to be 6.9 m/s instead of 4.98. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of WI
Forest County is the 1,461st 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 Forest County
February is the strongest month here, at 5.81 m/s and about 1,405 kWh. August is the weakest, 4.21 m/s and 651 kWh, so the best month makes 2.2 times the worst. November to March brings in 51% of the year's output in Forest County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 5.55 m/s | 1,395 kWh | $266 |
| February | 5.81 m/s | 1,405 kWh | $268 |
| March | 5.42 m/s | 1,310 kWh | $250 |
| April | 5.42 m/s | 1,268 kWh | $242 |
| May | 4.78 m/s | 940 kWh | $179 |
| June | 4.38 m/s | 710 kWh | $135 |
| July | 4.21 m/s | 651 kWh | $124 |
| August | 4.21 m/s | 651 kWh | $124 |
| September | 4.64 m/s | 838 kWh | $160 |
| October | 5.02 m/s | 1,075 kWh | $205 |
| November | 5.11 m/s | 1,094 kWh | $208 |
| December | 5.22 m/s | 1,191 kWh | $227 |
What a taller tower would buy
Measured at 10 m the wind in Forest County averages 3.62 m/s; at 50 m it is 5.77 m/s. That gives a shear exponent of 0.290, typical of ordinary open country. Going from 20 m to 50 m takes output from 8,886 to 18,006 kWh a year, 103% 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 | 4.42 m/s | 8,886 kWh | 59 years |
| 30 m | 4.98 m/s | 12,370 kWh | 42 years |
| 40 m | 5.41 m/s | 15,379 kWh | 34 years |
| 50 m | 5.77 m/s | 18,006 kWh | 29 years |
Counties around Forest County
2 of the 6 closest counties are windier at turbine height; the windiest, Langlade County, averages 5.8 m/s.
- Florence County, WI: 3.95 m/s, 6,329 kWh, payback 83 years (23 mi)
- Langlade County, WI: 5.8 m/s, 18,226 kWh, payback 29 years (32 mi)
- Iron County, MI: 4.06 m/s, 6,883 kWh, payback 67 years (37 mi)
- Oneida County, WI: 5.8 m/s, 18,226 kWh, payback 29 years (37 mi)
- Marinette County, WI: 4.71 m/s, 10,635 kWh, payback 49 years (44 mi)
- Vilas County, WI: 4.67 m/s, 10,382 kWh, payback 51 years (44 mi)
Sun versus wind in Forest County
Forest County gets 3.7 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,080 kWh a year; one kW of the turbine above makes 1,240. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.1 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.