Wind Turbine Payback in Dallas County, AL
Wind turbine payback in Dallas 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 Dallas County, AL averages 3.35 m/s (7.5 mph). A 10 kW turbine there would make about 3,757 kWh a year, worth $620 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 Dallas County
A home turbine is not worth buying for savings in Dallas County unless your spot is far windier than the county average, 7.5 m/s at the hub against 3.35 m/s here. Per kW, solar panels would make about 1,349 kWh a year here against the turbine's 376, so get a solar quote first.
What would have to change
- Power would have to cost 133¢/kWh, 8.1 times what AL pays now.
- Or the average wind at the hub would have to be 7.5 m/s instead of 3.35. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of AL
Dallas County is the 2,683rd 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 Dallas County
March is the strongest month here, at 3.84 m/s and about 493 kWh. July is the weakest, 2.54 m/s and 122 kWh, so the best month makes 4.0 times the worst. November to March brings in 56% of the year's output in Dallas County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.74 m/s | 452 kWh | $75 |
| February | 3.83 m/s | 443 kWh | $73 |
| March | 3.84 m/s | 493 kWh | $81 |
| April | 3.75 m/s | 444 kWh | $73 |
| May | 3.20 m/s | 274 kWh | $45 |
| June | 2.71 m/s | 150 kWh | $25 |
| July | 2.54 m/s | 122 kWh | $20 |
| August | 2.65 m/s | 143 kWh | $24 |
| September | 3.17 m/s | 256 kWh | $42 |
| October | 3.43 m/s | 346 kWh | $57 |
| November | 3.64 m/s | 403 kWh | $67 |
| December | 3.65 m/s | 419 kWh | $69 |
What a taller tower would buy
Measured at 10 m the wind in Dallas County averages 2.15 m/s; at 50 m it is 4.11 m/s. That gives a shear exponent of 0.403, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 2,154 to 7,143 kWh a year, 232% 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 | 2.84 m/s | 2,154 kWh | over 100 years |
| 30 m | 3.35 m/s | 3,740 kWh | over 100 years |
| 40 m | 3.76 m/s | 5,416 kWh | over 100 years |
| 50 m | 4.11 m/s | 7,143 kWh | 85 years |
Counties around Dallas County
None of the 6 closest counties is windier than Dallas County.
- Perry County, AL: 3.05 m/s, 2,751 kWh, payback over 100 years (24 mi)
- Wilcox County, AL: 2.94 m/s, 2,427 kWh, payback over 100 years (26 mi)
- Lowndes County, AL: 3 m/s, 2,601 kWh, payback over 100 years (30 mi)
- Autauga County, AL: 3.35 m/s, 3,757 kWh, payback over 100 years (31 mi)
- Marengo County, AL: 2.94 m/s, 2,427 kWh, payback over 100 years (40 mi)
- Hale County, AL: 2.97 m/s, 2,513 kWh, payback over 100 years (41 mi)
Sun versus wind in Dallas County
Dallas 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 376. Kilowatt for kilowatt, panels make 3.6 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.