Wind Turbine Payback in Coweta County, GA
Wind turbine payback in Coweta 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 Coweta County, GA averages 3.16 m/s (7.1 mph). A 10 kW turbine there would make about 3,099 kWh a year, worth $480 at GA's 15.48¢/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 Coweta County
A home turbine is not worth buying for savings in Coweta County unless your spot is far windier than the county average, 7.8 m/s at the hub against 3.16 m/s here. Per kW, solar panels would make about 1,317 kWh a year here against the turbine's 310, so get a solar quote first.
What would have to change
- Power would have to cost 161¢/kWh, 10.4 times what GA pays now.
- Or the average wind at the hub would have to be 7.8 m/s instead of 3.16. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of GA
Coweta County is the 2,928th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in GA is Glynn County at 5.08 m/s, payback 49 years.
Month by month in Coweta County
March is the strongest month here, at 3.66 m/s and about 425 kWh. July is the weakest, 2.42 m/s and 101 kWh, so the best month makes 4.2 times the worst. November to March brings in 57% of the year's output in Coweta County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.63 m/s | 411 kWh | $64 |
| February | 3.65 m/s | 379 kWh | $59 |
| March | 3.66 m/s | 425 kWh | $66 |
| April | 3.59 m/s | 384 kWh | $59 |
| May | 3.08 m/s | 241 kWh | $37 |
| June | 2.60 m/s | 129 kWh | $20 |
| July | 2.42 m/s | 101 kWh | $16 |
| August | 2.43 m/s | 102 kWh | $16 |
| September | 2.87 m/s | 184 kWh | $28 |
| October | 3.19 m/s | 273 kWh | $42 |
| November | 3.44 m/s | 336 kWh | $52 |
| December | 3.47 m/s | 357 kWh | $55 |
What a taller tower would buy
Measured at 10 m the wind in Coweta County averages 1.87 m/s; at 50 m it is 4.04 m/s. That gives a shear exponent of 0.479, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 1,576 to 6,780 kWh a year, 330% 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 | 2.6 m/s | 1,576 kWh | over 100 years |
| 30 m | 3.16 m/s | 3,109 kWh | over 100 years |
| 40 m | 3.63 m/s | 4,864 kWh | over 100 years |
| 50 m | 4.04 m/s | 6,780 kWh | 95 years |
Counties around Coweta County
2 of the 6 closest counties are windier at turbine height; the windiest, Fayette County, averages 3.86 m/s.
- Fayette County, GA: 3.86 m/s, 5,894 kWh, payback over 100 years (16 mi)
- Heard County, GA: 3.16 m/s, 3,099 kWh, payback over 100 years (22 mi)
- Meriwether County, GA: 3.15 m/s, 3,067 kWh, payback over 100 years (23 mi)
- Douglas County, GA: 3.16 m/s, 3,099 kWh, payback over 100 years (24 mi)
- Carroll County, GA: 3.16 m/s, 3,099 kWh, payback over 100 years (24 mi)
- Clayton County, GA: 3.86 m/s, 5,894 kWh, payback over 100 years (24 mi)
Sun versus wind in Coweta County
Coweta County gets 4.51 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,317 kWh a year; one kW of the turbine above makes 310. Kilowatt for kilowatt, panels make 4.2 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.