Wind Turbine Payback in Effingham County, GA
Wind turbine payback in Effingham 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 Effingham County, GA averages 3.48 m/s (7.8 mph). A 10 kW turbine there would make about 4,250 kWh a year, worth $658 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 Effingham County
A home turbine is not worth buying for savings in Effingham County unless your spot is far windier than the county average, 7.8 m/s at the hub against 3.48 m/s here. Per kW, solar panels would make about 1,369 kWh a year here against the turbine's 425, so get a solar quote first.
What would have to change
- Power would have to cost 118¢/kWh, 7.6 times what GA pays now.
- Or the average wind at the hub would have to be 7.8 m/s instead of 3.48. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of GA
Effingham County is the 2,536th 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 Effingham County
March is the strongest month here, at 3.94 m/s and about 534 kWh. August is the weakest, 2.84 m/s and 184 kWh, so the best month makes 2.9 times the worst. November to March brings in 50% of the year's output in Effingham County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.73 m/s | 451 kWh | $70 |
| February | 3.79 m/s | 427 kWh | $66 |
| March | 3.94 m/s | 534 kWh | $83 |
| April | 3.90 m/s | 501 kWh | $78 |
| May | 3.57 m/s | 393 kWh | $61 |
| June | 3.11 m/s | 241 kWh | $37 |
| July | 2.96 m/s | 212 kWh | $33 |
| August | 2.84 m/s | 184 kWh | $28 |
| September | 3.30 m/s | 294 kWh | $46 |
| October | 3.44 m/s | 347 kWh | $54 |
| November | 3.57 m/s | 380 kWh | $59 |
| December | 3.57 m/s | 390 kWh | $60 |
What a taller tower would buy
Measured at 10 m the wind in Effingham County averages 2.16 m/s; at 50 m it is 4.34 m/s. That gives a shear exponent of 0.434, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 2,359 to 8,403 kWh a year, 256% 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 | 2.92 m/s | 2,359 kWh | over 100 years |
| 30 m | 3.48 m/s | 4,238 kWh | over 100 years |
| 40 m | 3.94 m/s | 6,277 kWh | over 100 years |
| 50 m | 4.34 m/s | 8,403 kWh | 77 years |
Counties around Effingham County
5 of the 6 closest counties are windier at turbine height; the windiest, Bulloch County, averages 4.67 m/s.
- Jasper County, SC: 3.48 m/s, 4,250 kWh, payback over 100 years (19 mi)
- Bulloch County, GA: 4.67 m/s, 10,382 kWh, payback 62 years (23 mi)
- Bryan County, GA: 3.85 m/s, 5,847 kWh, payback over 100 years (24 mi)
- Chatham County, GA: 3.85 m/s, 5,847 kWh, payback over 100 years (30 mi)
- Screven County, GA: 4.67 m/s, 10,382 kWh, payback 62 years (31 mi)
- Hampton County, SC: 4.02 m/s, 6,678 kWh, payback 94 years (31 mi)
Sun versus wind in Effingham County
Effingham 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 425. Kilowatt for kilowatt, panels make 3.2 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.