Wind Turbine Payback in Fayette County, AL
Wind turbine payback in Fayette 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 Fayette County, AL averages 2.99 m/s (6.7 mph). A 10 kW turbine there would make about 2,571 kWh a year, worth $425 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 Fayette County
A home turbine is not worth buying for savings in Fayette County unless your spot is far windier than the county average, 7.5 m/s at the hub against 2.99 m/s here. Per kW, solar panels would make about 1,317 kWh a year here against the turbine's 257, so get a solar quote first.
What would have to change
- Power would have to cost 194¢/kWh, 11.8 times what AL pays now.
- Or the average wind at the hub would have to be 7.5 m/s instead of 2.99. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of AL
Fayette County is the 3,065th 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 Fayette County
March is the strongest month here, at 3.46 m/s and about 354 kWh. July is the weakest, 2.27 m/s and 78 kWh, so the best month makes 4.5 times the worst. November to March brings in 56% of the year's output in Fayette County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.30 m/s | 305 kWh | $50 |
| February | 3.44 m/s | 315 kWh | $52 |
| March | 3.46 m/s | 354 kWh | $58 |
| April | 3.44 m/s | 338 kWh | $56 |
| May | 2.89 m/s | 195 kWh | $32 |
| June | 2.49 m/s | 109 kWh | $18 |
| July | 2.27 m/s | 78 kWh | $13 |
| August | 2.35 m/s | 91 kWh | $15 |
| September | 2.79 m/s | 166 kWh | $27 |
| October | 3.05 m/s | 233 kWh | $38 |
| November | 3.20 m/s | 266 kWh | $44 |
| December | 3.21 m/s | 278 kWh | $46 |
What a taller tower would buy
Measured at 10 m the wind in Fayette County averages 1.75 m/s; at 50 m it is 3.84 m/s. That gives a shear exponent of 0.488, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 1,261 to 5,800 kWh a year, 360% 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 | 2.46 m/s | 1,261 kWh | over 100 years |
| 30 m | 2.99 m/s | 2,580 kWh | over 100 years |
| 40 m | 3.44 m/s | 4,109 kWh | over 100 years |
| 50 m | 3.84 m/s | 5,800 kWh | over 100 years |
Counties around Fayette County
5 of the 6 closest counties are windier at turbine height; the windiest, Lamar County, averages 3.15 m/s.
- Lamar County, AL: 3.15 m/s, 3,067 kWh, payback over 100 years (19 mi)
- Walker County, AL: 3.15 m/s, 3,067 kWh, payback over 100 years (27 mi)
- Marion County, AL: 3.15 m/s, 3,067 kWh, payback over 100 years (30 mi)
- Tuscaloosa County, AL: 2.99 m/s, 2,571 kWh, payback over 100 years (33 mi)
- Pickens County, AL: 3.08 m/s, 2,844 kWh, payback over 100 years (35 mi)
- Winston County, AL: 3.15 m/s, 3,067 kWh, payback over 100 years (38 mi)
Sun versus wind in Fayette County
Fayette County gets 4.51 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,317 kWh a year; one kW of the turbine above makes 257. Kilowatt for kilowatt, panels make 5.1 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.