Wind Turbine Payback in Cass County, MI
Wind turbine payback in Cass 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 Cass County, MI averages 6.35 m/s (14.2 mph). A 10 kW turbine there would make about 22,299 kWh a year, worth $4,846 at MI's 21.73¢/kWh. Against an installed cost of about $100,000, that is a payback of 21 years, and the turbine is built to last about 20.
What to do in Cass County
A home turbine is not worth buying for savings in Cass County unless your spot is far windier than the county average, 6.4 m/s at the hub against 6.35 m/s here. Per kW, solar panels would make about 1,113 kWh a year here against the turbine's 2,230, so get a solar quote first.
What would have to change
- Power would have to cost 22¢/kWh, 1.0 times what MI pays now.
- Or the average wind at the hub would have to be 6.4 m/s instead of 6.35. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of MI
Cass County is the 402nd 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 Cass County
January is the strongest month here, at 7.40 m/s and about 2,533 kWh. August is the weakest, 4.77 m/s and 936 kWh, so the best month makes 2.7 times the worst. November to March brings in 52% of the year's output in Cass County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 7.40 m/s | 2,533 kWh | $550 |
| February | 7.20 m/s | 2,181 kWh | $474 |
| March | 6.85 m/s | 2,207 kWh | $480 |
| April | 7.03 m/s | 2,242 kWh | $487 |
| May | 6.13 m/s | 1,754 kWh | $381 |
| June | 5.33 m/s | 1,219 kWh | $265 |
| July | 4.79 m/s | 946 kWh | $206 |
| August | 4.77 m/s | 936 kWh | $203 |
| September | 5.60 m/s | 1,380 kWh | $300 |
| October | 6.78 m/s | 2,162 kWh | $470 |
| November | 7.23 m/s | 2,358 kWh | $512 |
| December | 7.20 m/s | 2,415 kWh | $525 |
What a taller tower would buy
Measured at 10 m the wind in Cass County averages 5.13 m/s; at 50 m it is 7.02 m/s. That gives a shear exponent of 0.195, typical of ordinary open country. Going from 20 m to 50 m takes output from 18,752 to 27,186 kWh a year, 45% 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 | 5.87 m/s | 18,752 kWh | 25 years |
| 30 m | 6.35 m/s | 22,332 kWh | 21 years |
| 40 m | 6.72 m/s | 25,028 kWh | 18 years |
| 50 m | 7.02 m/s | 27,186 kWh | 17 years |
Counties around Cass County
1 of the 6 closest counties is windier at turbine height; the windiest, Van Buren County, averages 6.61 m/s.
- Elkhart County, IN: 5.99 m/s, 19,630 kWh, payback 30 years (23 mi)
- St. Joseph County, MI: 6.05 m/s, 20,075 kWh, payback 23 years (25 mi)
- St. Joseph County, IN: 5.96 m/s, 19,408 kWh, payback 30 years (25 mi)
- Van Buren County, MI: 6.61 m/s, 24,216 kWh, payback 19 years (30 mi)
- Kalamazoo County, MI: 6.05 m/s, 20,075 kWh, payback 23 years (33 mi)
- LaGrange County, IN: 5.99 m/s, 19,630 kWh, payback 30 years (35 mi)
Sun versus wind in Cass County
Cass County gets 3.81 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,113 kWh a year; one kW of the turbine above makes 2,230. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 2.0 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.