Wind Turbine Payback in Greene County, IN
Wind turbine payback in Greene 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 Greene County, IN averages 4.68 m/s (10.5 mph). A 10 kW turbine there would make about 10,445 kWh a year, worth $1,780 at IN's 17.04¢/kWh. Against an installed cost of about $100,000, that is a payback of 56 years, and the turbine is built to last about 20.
What to do in Greene County
A home turbine is not worth buying for savings in Greene County unless your spot is far windier than the county average, 7.3 m/s at the hub against 4.68 m/s here. Per kW, solar panels would make about 1,180 kWh a year here against the turbine's 1,045, so get a solar quote first.
What would have to change
- Power would have to cost 48¢/kWh, 2.8 times what IN pays now.
- Or the average wind at the hub would have to be 7.3 m/s instead of 4.68. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of IN
Greene County is the 1,635th 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 Greene County
April is the strongest month here, at 5.52 m/s and about 1,330 kWh. July is the weakest, 3.47 m/s and 359 kWh, so the best month makes 3.7 times the worst. November to March brings in 55% of the year's output in Greene County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 5.39 m/s | 1,296 kWh | $221 |
| February | 5.39 m/s | 1,170 kWh | $199 |
| March | 5.41 m/s | 1,306 kWh | $223 |
| April | 5.52 m/s | 1,330 kWh | $227 |
| May | 4.62 m/s | 856 kWh | $146 |
| June | 4.00 m/s | 539 kWh | $92 |
| July | 3.47 m/s | 359 kWh | $61 |
| August | 3.48 m/s | 362 kWh | $62 |
| September | 3.94 m/s | 515 kWh | $88 |
| October | 4.73 m/s | 915 kWh | $156 |
| November | 5.10 m/s | 1,086 kWh | $185 |
| December | 5.13 m/s | 1,137 kWh | $194 |
What a taller tower would buy
Measured at 10 m the wind in Greene County averages 3.35 m/s; at 50 m it is 5.47 m/s. That gives a shear exponent of 0.305, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 7,282 to 15,821 kWh a year, 117% 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 | 4.14 m/s | 7,282 kWh | 81 years |
| 30 m | 4.68 m/s | 10,450 kWh | 56 years |
| 40 m | 5.11 m/s | 13,284 kWh | 44 years |
| 50 m | 5.47 m/s | 15,821 kWh | 37 years |
Counties around Greene County
3 of the 6 closest counties are windier at turbine height; the windiest, Sullivan County, averages 5.61 m/s.
- Owen County, IN: 5.14 m/s, 13,490 kWh, payback 44 years (21 mi)
- Sullivan County, IN: 5.61 m/s, 16,834 kWh, payback 35 years (22 mi)
- Daviess County, IN: 4.61 m/s, 10,008 kWh, payback 59 years (25 mi)
- Clay County, IN: 5.14 m/s, 13,490 kWh, payback 44 years (25 mi)
- Martin County, IN: 4.61 m/s, 10,008 kWh, payback 59 years (26 mi)
- Monroe County, IN: 4.32 m/s, 8,289 kWh, payback 71 years (27 mi)
Sun versus wind in Greene County
Greene County gets 4.04 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,180 kWh a year; one kW of the turbine above makes 1,045. Kilowatt for kilowatt, panels make 1.1 times as much here as the turbine. 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.