Wind Turbine Payback in Cass County, IN
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, IN averages 5.94 m/s (13.3 mph). A 10 kW turbine there would make about 19,260 kWh a year, worth $3,282 at IN's 17.04¢/kWh. Against an installed cost of about $100,000, that is a payback of 31 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, 7.3 m/s at the hub against 5.94 m/s here. Per kW, solar panels would make about 1,159 kWh a year here against the turbine's 1,926, so get a solar quote first.
What would have to change
- Power would have to cost 26¢/kWh, 1.5 times what IN pays now.
- Or the average wind at the hub would have to be 7.3 m/s instead of 5.94. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of IN
Cass County is the 934th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in IN is Lake County at 6.17 m/s, payback 28 years.
Month by month in Cass County
April is the strongest month here, at 6.88 m/s and about 2,152 kWh. July is the weakest, 4.53 m/s and 809 kWh, so the best month makes 2.7 times the worst. November to March brings in 51% of the year's output in Cass County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.72 m/s | 2,125 kWh | $362 |
| February | 6.61 m/s | 1,859 kWh | $317 |
| March | 6.54 m/s | 2,014 kWh | $343 |
| April | 6.88 m/s | 2,152 kWh | $367 |
| May | 5.94 m/s | 1,634 kWh | $278 |
| June | 5.17 m/s | 1,127 kWh | $192 |
| July | 4.53 m/s | 809 kWh | $138 |
| August | 4.54 m/s | 813 kWh | $139 |
| September | 5.13 m/s | 1,101 kWh | $188 |
| October | 6.19 m/s | 1,791 kWh | $305 |
| November | 6.59 m/s | 1,976 kWh | $337 |
| December | 6.51 m/s | 1,992 kWh | $339 |
What a taller tower would buy
Measured at 10 m the wind in Cass County averages 4.62 m/s; at 50 m it is 6.67 m/s. That gives a shear exponent of 0.228, typical of ordinary open country. Going from 20 m to 50 m takes output from 15,408 to 24,655 kWh a year, 60% 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 | 5.41 m/s | 15,408 kWh | 38 years |
| 30 m | 5.94 m/s | 19,235 kWh | 31 years |
| 40 m | 6.34 m/s | 22,219 kWh | 26 years |
| 50 m | 6.67 m/s | 24,655 kWh | 24 years |
Counties around Cass County
4 of the 6 closest counties are windier at turbine height; the windiest, Carroll County, averages 5.97 m/s.
- Carroll County, IN: 5.97 m/s, 19,482 kWh, payback 30 years (16 mi)
- Miami County, IN: 5.94 m/s, 19,260 kWh, payback 31 years (16 mi)
- Fulton County, IN: 5.94 m/s, 19,260 kWh, payback 31 years (21 mi)
- Howard County, IN: 5.95 m/s, 19,334 kWh, payback 30 years (23 mi)
- White County, IN: 5.97 m/s, 19,482 kWh, payback 30 years (27 mi)
- Pulaski County, IN: 5.97 m/s, 19,482 kWh, payback 30 years (27 mi)
Sun versus wind in Cass County
Cass County gets 3.97 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,159 kWh a year; one kW of the turbine above makes 1,926. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.7 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.