Wind Turbine Payback in Perry County, AL
Wind turbine payback in Perry 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 Perry County, AL averages 3.05 m/s (6.8 mph). A 10 kW turbine there would make about 2,751 kWh a year, worth $454 at AL's 16.51¢/kWh. Against an installed cost of about $100,000, that is a payback of over 100 years, and the turbine is built to last about 20.
What to do in Perry County
A home turbine is not worth buying for savings in Perry County unless your spot is far windier than the county average, 7.5 m/s at the hub against 3.05 m/s here. Per kW, solar panels would make about 1,349 kWh a year here against the turbine's 275, so get a solar quote first.
What would have to change
- Power would have to cost 182¢/kWh, 11.0 times what AL pays now.
- Or the average wind at the hub would have to be 7.5 m/s instead of 3.05. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of AL
Perry County is the 3,024th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in AL is Mobile County at 4.72 m/s, payback 57 years.
Month by month in Perry County
March is the strongest month here, at 3.52 m/s and about 374 kWh. July is the weakest, 2.34 m/s and 88 kWh, so the best month makes 4.3 times the worst. November to March brings in 56% of the year's output in Perry County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.39 m/s | 332 kWh | $55 |
| February | 3.50 m/s | 331 kWh | $55 |
| March | 3.52 m/s | 374 kWh | $62 |
| April | 3.47 m/s | 347 kWh | $57 |
| May | 2.95 m/s | 208 kWh | $34 |
| June | 2.51 m/s | 113 kWh | $19 |
| July | 2.34 m/s | 88 kWh | $15 |
| August | 2.42 m/s | 101 kWh | $17 |
| September | 2.85 m/s | 180 kWh | $30 |
| October | 3.11 m/s | 251 kWh | $41 |
| November | 3.29 m/s | 291 kWh | $48 |
| December | 3.32 m/s | 310 kWh | $51 |
What a taller tower would buy
Measured at 10 m the wind in Perry County averages 1.85 m/s; at 50 m it is 3.85 m/s. That gives a shear exponent of 0.455, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 1,429 to 5,847 kWh a year, 309% 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 | 2.54 m/s | 1,429 kWh | over 100 years |
| 30 m | 3.05 m/s | 2,756 kWh | over 100 years |
| 40 m | 3.48 m/s | 4,243 kWh | over 100 years |
| 50 m | 3.85 m/s | 5,847 kWh | over 100 years |
Counties around Perry County
4 of the 6 closest counties are windier at turbine height; the windiest, Dallas County, averages 3.35 m/s.
- Hale County, AL: 2.97 m/s, 2,513 kWh, payback over 100 years (21 mi)
- Dallas County, AL: 3.35 m/s, 3,757 kWh, payback over 100 years (24 mi)
- Bibb County, AL: 3.13 m/s, 3,002 kWh, payback over 100 years (28 mi)
- Chilton County, AL: 3.13 m/s, 3,002 kWh, payback over 100 years (36 mi)
- Autauga County, AL: 3.35 m/s, 3,757 kWh, payback over 100 years (38 mi)
- Marengo County, AL: 2.94 m/s, 2,427 kWh, payback over 100 years (40 mi)
Sun versus wind in Perry County
Perry County gets 4.62 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,349 kWh a year; one kW of the turbine above makes 275. Kilowatt for kilowatt, panels make 4.9 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.