Wind Turbine Payback in Screven County, GA
Wind turbine payback in Screven 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 Screven County, GA averages 4.67 m/s (10.4 mph). A 10 kW turbine there would make about 10,382 kWh a year, worth $1,607 at GA's 15.48¢/kWh. Against an installed cost of about $100,000, that is a payback of 62 years, and the turbine is built to last about 20.
What to do in Screven County
A home turbine is not worth buying for savings in Screven County unless your spot is far windier than the county average, 7.8 m/s at the hub against 4.67 m/s here. Per kW, solar panels would make about 1,369 kWh a year here against the turbine's 1,038, so get a solar quote first.
What would have to change
- Power would have to cost 48¢/kWh, 3.1 times what GA pays now.
- Or the average wind at the hub would have to be 7.8 m/s instead of 4.67. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of GA
Screven County is the 1,639th 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 Screven County
March is the strongest month here, at 5.40 m/s and about 1,302 kWh. August is the weakest, 3.66 m/s and 422 kWh, so the best month makes 3.1 times the worst. November to March brings in 52% of the year's output in Screven County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 5.20 m/s | 1,181 kWh | $183 |
| February | 5.23 m/s | 1,081 kWh | $167 |
| March | 5.40 m/s | 1,302 kWh | $202 |
| April | 5.25 m/s | 1,173 kWh | $182 |
| May | 4.70 m/s | 899 kWh | $139 |
| June | 4.06 m/s | 564 kWh | $87 |
| July | 3.84 m/s | 492 kWh | $76 |
| August | 3.66 m/s | 422 kWh | $65 |
| September | 4.34 m/s | 689 kWh | $107 |
| October | 4.62 m/s | 853 kWh | $132 |
| November | 4.87 m/s | 958 kWh | $148 |
| December | 4.95 m/s | 1,034 kWh | $160 |
What a taller tower would buy
Measured at 10 m the wind in Screven County averages 3.48 m/s; at 50 m it is 5.35 m/s. That gives a shear exponent of 0.267, typical of ordinary open country. Going from 20 m to 50 m takes output from 7,563 to 14,963 kWh a year, 98% 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 | 4.19 m/s | 7,563 kWh | 85 years |
| 30 m | 4.67 m/s | 10,369 kWh | 62 years |
| 40 m | 5.04 m/s | 12,809 kWh | 50 years |
| 50 m | 5.35 m/s | 14,963 kWh | 43 years |
Counties around Screven County
2 of the 6 closest counties are windier at turbine height; the windiest, Jenkins County, averages 4.77 m/s.
- Jenkins County, GA: 4.77 m/s, 11,018 kWh, payback 59 years (21 mi)
- Allendale County, SC: 4.02 m/s, 6,678 kWh, payback 94 years (22 mi)
- Bulloch County, GA: 4.67 m/s, 10,382 kWh, payback 62 years (25 mi)
- Hampton County, SC: 4.02 m/s, 6,678 kWh, payback 94 years (28 mi)
- Effingham County, GA: 3.48 m/s, 4,250 kWh, payback over 100 years (31 mi)
- Burke County, GA: 4.77 m/s, 11,018 kWh, payback 59 years (31 mi)
Sun versus wind in Screven County
Screven County gets 4.69 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,369 kWh a year; one kW of the turbine above makes 1,038. Kilowatt for kilowatt, panels make 1.3 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.