Wind Turbine Payback in Washington County, AL
Wind turbine payback in Washington 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 Washington County, AL averages 2.9 m/s (6.5 mph). A 10 kW turbine there would make about 2,315 kWh a year, worth $382 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 Washington County
A home turbine is not worth buying for savings in Washington County unless your spot is far windier than the county average, 7.5 m/s at the hub against 2.9 m/s here. Per kW, solar panels would make about 1,355 kWh a year here against the turbine's 232, so get a solar quote first.
What would have to change
- Power would have to cost 216¢/kWh, 13.1 times what AL pays now.
- Or the average wind at the hub would have to be 7.5 m/s instead of 2.9. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of AL
Washington County is the 3,106th 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 Washington County
March is the strongest month here, at 3.27 m/s and about 294 kWh. July is the weakest, 2.27 m/s and 78 kWh, so the best month makes 3.8 times the worst. November to March brings in 55% of the year's output in Washington County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.17 m/s | 267 kWh | $44 |
| February | 3.24 m/s | 257 kWh | $42 |
| March | 3.27 m/s | 294 kWh | $49 |
| April | 3.24 m/s | 276 kWh | $46 |
| May | 2.86 m/s | 188 kWh | $31 |
| June | 2.47 m/s | 106 kWh | $18 |
| July | 2.27 m/s | 78 kWh | $13 |
| August | 2.32 m/s | 86 kWh | $14 |
| September | 2.69 m/s | 145 kWh | $24 |
| October | 2.98 m/s | 216 kWh | $36 |
| November | 3.15 m/s | 252 kWh | $42 |
| December | 3.14 m/s | 257 kWh | $42 |
What a taller tower would buy
Measured at 10 m the wind in Washington County averages 1.68 m/s; at 50 m it is 3.73 m/s. That gives a shear exponent of 0.496, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 1,093 to 5,297 kWh a year, 385% 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 | 2.37 m/s | 1,093 kWh | over 100 years |
| 30 m | 2.9 m/s | 2,301 kWh | over 100 years |
| 40 m | 3.34 m/s | 3,718 kWh | over 100 years |
| 50 m | 3.73 m/s | 5,297 kWh | over 100 years |
Counties around Washington County
4 of the 6 closest counties are windier at turbine height; the windiest, Greene County, averages 3.41 m/s.
- Greene County, MS: 3.41 m/s, 3,980 kWh, payback over 100 years (28 mi)
- Clarke County, AL: 2.9 m/s, 2,315 kWh, payback over 100 years (30 mi)
- Wayne County, MS: 2.92 m/s, 2,370 kWh, payback over 100 years (32 mi)
- Choctaw County, AL: 2.9 m/s, 2,315 kWh, payback over 100 years (40 mi)
- George County, MS: 3.41 m/s, 3,980 kWh, payback over 100 years (46 mi)
- Perry County, MS: 3.41 m/s, 3,980 kWh, payback over 100 years (49 mi)
Sun versus wind in Washington County
Washington County gets 4.64 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,355 kWh a year; one kW of the turbine above makes 232. Kilowatt for kilowatt, panels make 5.8 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.