Wind Turbine Payback in Washtenaw County, MI
Wind turbine payback in Washtenaw 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 Washtenaw County, MI averages 6.09 m/s (13.6 mph). A 10 kW turbine there would make about 20,371 kWh a year, worth $4,427 at MI's 21.73¢/kWh. Against an installed cost of about $100,000, that is a payback of 23 years, and the turbine is built to last about 20.
What to do in Washtenaw County
A home turbine is not worth buying for savings in Washtenaw County unless your spot is far windier than the county average, 6.4 m/s at the hub against 6.09 m/s here. Per kW, solar panels would make about 1,107 kWh a year here against the turbine's 2,037, so get a solar quote first.
What would have to change
- Power would have to cost 25¢/kWh, 1.1 times what MI pays now.
- Or the average wind at the hub would have to be 6.4 m/s instead of 6.09. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of MI
Washtenaw County is the 701st windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in MI is Keweenaw County at 7.4 m/s, payback 15 years.
Month by month in Washtenaw County
January is the strongest month here, at 6.90 m/s and about 2,238 kWh. August is the weakest, 4.81 m/s and 956 kWh, so the best month makes 2.3 times the worst. November to March brings in 51% of the year's output in Washtenaw County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.90 m/s | 2,238 kWh | $486 |
| February | 6.89 m/s | 2,011 kWh | $437 |
| March | 6.62 m/s | 2,062 kWh | $448 |
| April | 6.82 m/s | 2,118 kWh | $460 |
| May | 5.89 m/s | 1,602 kWh | $348 |
| June | 5.30 m/s | 1,199 kWh | $261 |
| July | 4.83 m/s | 971 kWh | $211 |
| August | 4.81 m/s | 956 kWh | $208 |
| September | 5.39 m/s | 1,251 kWh | $272 |
| October | 6.43 m/s | 1,944 kWh | $422 |
| November | 6.68 m/s | 2,033 kWh | $442 |
| December | 6.64 m/s | 2,078 kWh | $452 |
What a taller tower would buy
Measured at 10 m the wind in Washtenaw County averages 4.76 m/s; at 50 m it is 6.83 m/s. That gives a shear exponent of 0.224, typical of ordinary open country. Going from 20 m to 50 m takes output from 16,490 to 25,819 kWh a year, 57% 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 | 16,490 kWh | 28 years |
| 30 m | 6.09 m/s | 20,383 kWh | 23 years |
| 40 m | 6.5 m/s | 23,385 kWh | 20 years |
| 50 m | 6.83 m/s | 25,819 kWh | 18 years |
Counties around Washtenaw County
4 of the 6 closest counties are windier at turbine height; the windiest, Wayne County, averages 6.17 m/s.
- Livingston County, MI: 6.09 m/s, 20,371 kWh, payback 23 years (24 mi)
- Lenawee County, MI: 6.12 m/s, 20,594 kWh, payback 22 years (27 mi)
- Jackson County, MI: 6.12 m/s, 20,594 kWh, payback 22 years (30 mi)
- Monroe County, MI: 6.03 m/s, 19,926 kWh, payback 23 years (30 mi)
- Wayne County, MI: 6.17 m/s, 20,965 kWh, payback 22 years (30 mi)
- Ingham County, MI: 6.17 m/s, 20,965 kWh, payback 22 years (36 mi)
Sun versus wind in Washtenaw County
Washtenaw County gets 3.79 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,107 kWh a year; one kW of the turbine above makes 2,037. 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.