Wind Turbine Payback in Miller County, GA
Wind turbine payback in Miller 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 Miller County, GA averages 4.4 m/s (9.8 mph). A 10 kW turbine there would make about 8,748 kWh a year, worth $1,354 at GA's 15.48¢/kWh. Against an installed cost of about $100,000, that is a payback of 74 years, and the turbine is built to last about 20.
What to do in Miller County
A home turbine is not worth buying for savings in Miller County unless your spot is far windier than the county average, 7.8 m/s at the hub against 4.4 m/s here. Per kW, solar panels would make about 1,396 kWh a year here against the turbine's 875, so get a solar quote first.
What would have to change
- Power would have to cost 57¢/kWh, 3.7 times what GA pays now.
- Or the average wind at the hub would have to be 7.8 m/s instead of 4.4. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of GA
Miller County is the 1,818th 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 Miller County
March is the strongest month here, at 4.96 m/s and about 1,043 kWh. July is the weakest, 3.46 m/s and 355 kWh, so the best month makes 2.9 times the worst. November to March brings in 54% of the year's output in Miller County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 4.91 m/s | 1,014 kWh | $157 |
| February | 4.93 m/s | 925 kWh | $143 |
| March | 4.96 m/s | 1,043 kWh | $161 |
| April | 4.71 m/s | 875 kWh | $135 |
| May | 4.17 m/s | 635 kWh | $98 |
| June | 3.63 m/s | 398 kWh | $62 |
| July | 3.46 m/s | 355 kWh | $55 |
| August | 3.51 m/s | 372 kWh | $58 |
| September | 4.29 m/s | 666 kWh | $103 |
| October | 4.60 m/s | 844 kWh | $131 |
| November | 4.82 m/s | 934 kWh | $145 |
| December | 4.83 m/s | 970 kWh | $150 |
What a taller tower would buy
Measured at 10 m the wind in Miller County averages 3.24 m/s; at 50 m it is 5.07 m/s. That gives a shear exponent of 0.278, typical of ordinary open country. Going from 20 m to 50 m takes output from 6,230 to 13,010 kWh a year, 109% 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 | 3.93 m/s | 6,230 kWh | over 100 years |
| 30 m | 4.4 m/s | 8,741 kWh | 74 years |
| 40 m | 4.77 m/s | 10,986 kWh | 59 years |
| 50 m | 5.07 m/s | 13,010 kWh | 50 years |
Counties around Miller County
2 of the 6 closest counties are windier at turbine height; the windiest, Baker County, averages 4.66 m/s.
- Early County, GA: 4.18 m/s, 7,515 kWh, payback 86 years (15 mi)
- Seminole County, GA: 4.4 m/s, 8,748 kWh, payback 74 years (18 mi)
- Baker County, GA: 4.66 m/s, 10,320 kWh, payback 63 years (20 mi)
- Decatur County, GA: 3.91 m/s, 6,134 kWh, payback over 100 years (21 mi)
- Calhoun County, GA: 4.66 m/s, 10,320 kWh, payback 63 years (26 mi)
- Mitchell County, GA: 3.91 m/s, 6,134 kWh, payback over 100 years (32 mi)
Sun versus wind in Miller County
Miller County gets 4.78 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,396 kWh a year; one kW of the turbine above makes 875. Kilowatt for kilowatt, panels make 1.6 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.