Wind Turbine Payback in Lawrence County, AL
Wind turbine payback in Lawrence 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 Lawrence County, AL averages 3.87 m/s (8.7 mph). A 10 kW turbine there would make about 5,942 kWh a year, worth $981 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 Lawrence County
A home turbine is not worth buying for savings in Lawrence County unless your spot is far windier than the county average, 7.5 m/s at the hub against 3.87 m/s here. Per kW, solar panels would make about 1,296 kWh a year here against the turbine's 594, so get a solar quote first.
What would have to change
- Power would have to cost 84¢/kWh, 5.1 times what AL pays now.
- Or the average wind at the hub would have to be 7.5 m/s instead of 3.87. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of AL
Lawrence County is the 2,157th 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 Lawrence County
March is the strongest month here, at 4.59 m/s and about 839 kWh. July is the weakest, 2.80 m/s and 174 kWh, so the best month makes 4.8 times the worst. November to March brings in 58% of the year's output in Lawrence County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 4.44 m/s | 762 kWh | $126 |
| February | 4.61 m/s | 770 kWh | $127 |
| March | 4.59 m/s | 839 kWh | $139 |
| April | 4.54 m/s | 787 kWh | $130 |
| May | 3.75 m/s | 457 kWh | $75 |
| June | 3.12 m/s | 244 kWh | $40 |
| July | 2.80 m/s | 174 kWh | $29 |
| August | 2.90 m/s | 197 kWh | $33 |
| September | 3.45 m/s | 339 kWh | $56 |
| October | 3.85 m/s | 497 kWh | $82 |
| November | 4.18 m/s | 617 kWh | $102 |
| December | 4.27 m/s | 680 kWh | $112 |
What a taller tower would buy
Measured at 10 m the wind in Lawrence County averages 2.66 m/s; at 50 m it is 4.6 m/s. That gives a shear exponent of 0.340, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 3,826 to 9,947 kWh a year, 160% 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 | 3.37 m/s | 3,826 kWh | over 100 years |
| 30 m | 3.87 m/s | 5,926 kWh | over 100 years |
| 40 m | 4.26 m/s | 7,974 kWh | 76 years |
| 50 m | 4.6 m/s | 9,947 kWh | 61 years |
Counties around Lawrence County
2 of the 6 closest counties are windier at turbine height; the windiest, Lauderdale County, averages 4.02 m/s.
- Winston County, AL: 3.15 m/s, 3,067 kWh, payback over 100 years (26 mi)
- Limestone County, AL: 3.99 m/s, 6,527 kWh, payback 93 years (27 mi)
- Morgan County, AL: 3.84 m/s, 5,800 kWh, payback over 100 years (28 mi)
- Colbert County, AL: 3.87 m/s, 5,942 kWh, payback over 100 years (30 mi)
- Franklin County, AL: 3.31 m/s, 3,612 kWh, payback over 100 years (30 mi)
- Lauderdale County, AL: 4.02 m/s, 6,678 kWh, payback 91 years (32 mi)
Sun versus wind in Lawrence County
Lawrence County gets 4.44 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,296 kWh a year; one kW of the turbine above makes 594. Kilowatt for kilowatt, panels make 2.2 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.