Wind Turbine Payback in Montgomery County, AL
Wind turbine payback in Montgomery 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 Montgomery County, AL averages 3.04 m/s (6.8 mph). A 10 kW turbine there would make about 2,721 kWh a year, worth $449 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 Montgomery County
A home turbine is not worth buying for savings in Montgomery County unless your spot is far windier than the county average, 7.5 m/s at the hub against 3.04 m/s here. Per kW, solar panels would make about 1,346 kWh a year here against the turbine's 272, so get a solar quote first.
What would have to change
- Power would have to cost 184¢/kWh, 11.1 times what AL pays now.
- Or the average wind at the hub would have to be 7.5 m/s instead of 3.04. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of AL
Montgomery County is the 3,036th 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 Montgomery County
March is the strongest month here, at 3.46 m/s and about 353 kWh. July is the weakest, 2.39 m/s and 96 kWh, so the best month makes 3.7 times the worst. November to March brings in 55% of the year's output in Montgomery County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.36 m/s | 323 kWh | $53 |
| February | 3.42 m/s | 310 kWh | $51 |
| March | 3.46 m/s | 353 kWh | $58 |
| April | 3.39 m/s | 320 kWh | $53 |
| May | 2.95 m/s | 208 kWh | $34 |
| June | 2.53 m/s | 116 kWh | $19 |
| July | 2.39 m/s | 96 kWh | $16 |
| August | 2.43 m/s | 103 kWh | $17 |
| September | 2.86 m/s | 182 kWh | $30 |
| October | 3.13 m/s | 255 kWh | $42 |
| November | 3.29 m/s | 292 kWh | $48 |
| December | 3.27 m/s | 294 kWh | $49 |
What a taller tower would buy
Measured at 10 m the wind in Montgomery County averages 1.78 m/s; at 50 m it is 3.89 m/s. That gives a shear exponent of 0.486, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 1,334 to 6,037 kWh a year, 353% 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 | 2.49 m/s | 1,334 kWh | over 100 years |
| 30 m | 3.03 m/s | 2,705 kWh | over 100 years |
| 40 m | 3.49 m/s | 4,290 kWh | over 100 years |
| 50 m | 3.89 m/s | 6,037 kWh | over 100 years |
Counties around Montgomery County
3 of the 6 closest counties are windier at turbine height; the windiest, Elmore County, averages 3.88 m/s.
- Lowndes County, AL: 3 m/s, 2,601 kWh, payback over 100 years (26 mi)
- Elmore County, AL: 3.88 m/s, 5,989 kWh, payback over 100 years (27 mi)
- Bullock County, AL: 3.04 m/s, 2,721 kWh, payback over 100 years (29 mi)
- Pike County, AL: 3.04 m/s, 2,721 kWh, payback over 100 years (32 mi)
- Macon County, AL: 3.26 m/s, 3,436 kWh, payback over 100 years (32 mi)
- Crenshaw County, AL: 3.1 m/s, 2,906 kWh, payback over 100 years (33 mi)
Sun versus wind in Montgomery County
Montgomery County gets 4.61 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,346 kWh a year; one kW of the turbine above makes 272. 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.