Wind Turbine Payback in Isabella County, MI
Wind turbine payback in Isabella 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 Isabella County, MI averages 6.01 m/s (13.4 mph). A 10 kW turbine there would make about 19,778 kWh a year, worth $4,298 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 Isabella County
A home turbine is not worth buying for savings in Isabella County unless your spot is far windier than the county average, 6.4 m/s at the hub against 6.01 m/s here. Per kW, solar panels would make about 1,095 kWh a year here against the turbine's 1,978, so get a solar quote first.
What would have to change
- Power would have to cost 25¢/kWh, 1.2 times what MI pays now.
- Or the average wind at the hub would have to be 6.4 m/s instead of 6.01. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of MI
Isabella County is the 826th 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 Isabella County
January is the strongest month here, at 6.68 m/s and about 2,098 kWh. July is the weakest, 4.83 m/s and 970 kWh, so the best month makes 2.2 times the worst. November to March brings in 50% of the year's output in Isabella County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.68 m/s | 2,098 kWh | $456 |
| February | 6.77 m/s | 1,945 kWh | $423 |
| March | 6.44 m/s | 1,948 kWh | $423 |
| April | 6.68 m/s | 2,031 kWh | $441 |
| May | 5.93 m/s | 1,628 kWh | $354 |
| June | 5.26 m/s | 1,177 kWh | $256 |
| July | 4.83 m/s | 970 kWh | $211 |
| August | 4.89 m/s | 1,004 kWh | $218 |
| September | 5.37 m/s | 1,239 kWh | $269 |
| October | 6.29 m/s | 1,858 kWh | $404 |
| November | 6.51 m/s | 1,928 kWh | $419 |
| December | 6.50 m/s | 1,987 kWh | $432 |
What a taller tower would buy
Measured at 10 m the wind in Isabella County averages 4.69 m/s; at 50 m it is 6.74 m/s. That gives a shear exponent of 0.225, typical of ordinary open country. Going from 20 m to 50 m takes output from 15,924 to 25,166 kWh a year, 58% 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 | 5.48 m/s | 15,924 kWh | 29 years |
| 30 m | 6.01 m/s | 19,765 kWh | 23 years |
| 40 m | 6.41 m/s | 22,743 kWh | 20 years |
| 50 m | 6.74 m/s | 25,166 kWh | 18 years |
Counties around Isabella County
None of the 6 closest counties is windier than Isabella County.
- Midland County, MI: 5.82 m/s, 18,374 kWh, payback 25 years (23 mi)
- Clare County, MI: 5.26 m/s, 14,327 kWh, payback 32 years (24 mi)
- Mecosta County, MI: 5.89 m/s, 18,890 kWh, payback 24 years (25 mi)
- Gratiot County, MI: 5.82 m/s, 18,374 kWh, payback 25 years (27 mi)
- Montcalm County, MI: 6.01 m/s, 19,778 kWh, payback 23 years (28 mi)
- Gladwin County, MI: 4.8 m/s, 11,212 kWh, payback 41 years (33 mi)
Sun versus wind in Isabella County
Isabella County gets 3.75 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,095 kWh a year; one kW of the turbine above makes 1,978. 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.