Wind Turbine Payback in Henry County, AL
Wind turbine payback in Henry 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 Henry County, AL averages 4.18 m/s (9.4 mph). A 10 kW turbine there would make about 7,515 kWh a year, worth $1,241 at AL's 16.51¢/kWh. Against an installed cost of about $100,000, that is a payback of 81 years, and the turbine is built to last about 20.
What to do in Henry County
A home turbine is not worth buying for savings in Henry County unless your spot is far windier than the county average, 7.5 m/s at the hub against 4.18 m/s here. Per kW, solar panels would make about 1,387 kWh a year here against the turbine's 752, so get a solar quote first.
What would have to change
- Power would have to cost 67¢/kWh, 4.0 times what AL pays now.
- Or the average wind at the hub would have to be 7.5 m/s instead of 4.18. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of AL
Henry County is the 1,957th 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 Henry County
March is the strongest month here, at 4.73 m/s and about 914 kWh. July is the weakest, 3.31 m/s and 307 kWh, so the best month makes 3.0 times the worst. November to March brings in 54% of the year's output in Henry County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 4.64 m/s | 868 kWh | $143 |
| February | 4.68 m/s | 801 kWh | $132 |
| March | 4.73 m/s | 914 kWh | $151 |
| April | 4.54 m/s | 788 kWh | $130 |
| May | 4.00 m/s | 560 kWh | $92 |
| June | 3.46 m/s | 344 kWh | $57 |
| July | 3.31 m/s | 307 kWh | $51 |
| August | 3.36 m/s | 323 kWh | $53 |
| September | 4.06 m/s | 567 kWh | $94 |
| October | 4.33 m/s | 708 kWh | $117 |
| November | 4.52 m/s | 780 kWh | $129 |
| December | 4.55 m/s | 819 kWh | $135 |
What a taller tower would buy
Measured at 10 m the wind in Henry County averages 2.99 m/s; at 50 m it is 4.89 m/s. That gives a shear exponent of 0.306, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 5,140 to 11,800 kWh a year, 130% 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 | 3.69 m/s | 5,140 kWh | over 100 years |
| 30 m | 4.18 m/s | 7,528 kWh | 81 years |
| 40 m | 4.57 m/s | 9,746 kWh | 62 years |
| 50 m | 4.89 m/s | 11,800 kWh | 51 years |
Counties around Henry County
1 of the 6 closest counties is windier at turbine height; the windiest, Houston County, averages 4.4 m/s.
- Clay County, GA: 4.18 m/s, 7,515 kWh, payback 86 years (16 mi)
- Dale County, AL: 3.29 m/s, 3,541 kWh, payback over 100 years (23 mi)
- Early County, GA: 4.18 m/s, 7,515 kWh, payback 86 years (24 mi)
- Houston County, AL: 4.4 m/s, 8,748 kWh, payback 69 years (25 mi)
- Barbour County, AL: 3.04 m/s, 2,721 kWh, payback over 100 years (26 mi)
- Quitman County, GA: 3.3 m/s, 3,577 kWh, payback over 100 years (28 mi)
Sun versus wind in Henry County
Henry County gets 4.75 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,387 kWh a year; one kW of the turbine above makes 752. Kilowatt for kilowatt, panels make 1.8 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.