Wind Turbine Payback in Door County, WI
Wind turbine payback in Door County
Only just. The money comes back late in the turbine's life.
At 30 m, the height a home turbine tower usually reaches, the wind in Door County, WI averages 7.26 m/s (16.2 mph). A 10 kW turbine there would make about 28,881 kWh a year, worth $5,502 at WI's 19.05¢/kWh. Against an installed cost of about $100,000, that is a payback of 18 years, and the turbine is built to last about 20.
What to do in Door County
It is close enough that your own site decides it. If you have open land with no trees or buildings upwind, ask an installer to log the wind at 30 m or higher; anything above 6.9 m/s pays back in time. Per kW, solar panels would make about 1,060 kWh a year here against the turbine's 2,888, so get a solar quote first.
What would have to change
- Power already costs enough here: break-even is 17¢/kWh and WI pays 19.05¢.
- The wind clears the break-even speed of 6.9 m/s at today's price.
Against the rest of WI
Door County is the 11th 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 Door County
January is the strongest month here, at 8.22 m/s and about 2,993 kWh. July is the weakest, 5.82 m/s and 1,564 kWh, so the best month makes 1.9 times the worst. November to March brings in 49% of the year's output in Door County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 8.22 m/s | 2,993 kWh | $570 |
| February | 8.09 m/s | 2,640 kWh | $503 |
| March | 7.42 m/s | 2,550 kWh | $486 |
| April | 7.52 m/s | 2,520 kWh | $480 |
| May | 6.94 m/s | 2,257 kWh | $430 |
| June | 6.30 m/s | 1,800 kWh | $343 |
| July | 5.82 m/s | 1,564 kWh | $298 |
| August | 5.84 m/s | 1,575 kWh | $300 |
| September | 6.89 m/s | 2,157 kWh | $411 |
| October | 7.85 m/s | 2,790 kWh | $531 |
| November | 8.20 m/s | 2,882 kWh | $549 |
| December | 8.20 m/s | 2,978 kWh | $567 |
What a taller tower would buy
Measured at 10 m the wind in Door County averages 6.37 m/s; at 50 m it is 7.72 m/s. That gives a shear exponent of 0.119, typical of very open, smooth ground where height adds little. Going from 20 m to 50 m takes output from 26,487 to 32,013 kWh a year, 21% 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 | 6.92 m/s | 26,487 kWh | 20 years |
| 30 m | 7.26 m/s | 28,914 kWh | 18 years |
| 40 m | 7.52 m/s | 30,656 kWh | 17 years |
| 50 m | 7.72 m/s | 32,013 kWh | 16 years |
Counties around Door County
2 of the 6 closest counties are windier at turbine height; the windiest, Leelanau County, averages 7.3 m/s.
- Menominee County, MI: 4.99 m/s, 12,467 kWh, payback 37 years (38 mi)
- Kewaunee County, WI: 7.28 m/s, 29,020 kWh, payback 18 years (39 mi)
- Leelanau County, MI: 7.3 m/s, 29,160 kWh, payback 16 years (49 mi)
- Marinette County, WI: 4.71 m/s, 10,635 kWh, payback 49 years (49 mi)
- Delta County, MI: 4.35 m/s, 8,460 kWh, payback 54 years (50 mi)
- Benzie County, MI: 6.94 m/s, 26,613 kWh, payback 17 years (51 mi)
Sun versus wind in Door County
Door County gets 3.63 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,060 kWh a year; one kW of the turbine above makes 2,888. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 2.7 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.