Wind Turbine Payback in Carroll County, VA
Wind turbine payback in Carroll 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 Carroll County, VA averages 3.78 m/s (8.5 mph). A 10 kW turbine there would make about 5,523 kWh a year, worth $936 at VA's 16.95¢/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 Carroll County
A home turbine is not worth buying for savings in Carroll County unless your spot is far windier than the county average, 7.3 m/s at the hub against 3.78 m/s here. Per kW, solar panels would make about 1,256 kWh a year here against the turbine's 552, so get a solar quote first.
What would have to change
- Power would have to cost 91¢/kWh, 5.3 times what VA pays now.
- Or the average wind at the hub would have to be 7.3 m/s instead of 3.78. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of VA
Carroll County is the 2,219th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in VA is Northampton County at 7.01 m/s, payback 22 years.
Month by month in Carroll County
March is the strongest month here, at 4.51 m/s and about 796 kWh. August is the weakest, 2.80 m/s and 173 kWh, so the best month makes 4.6 times the worst. November to March brings in 57% of the year's output in Carroll County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 4.36 m/s | 722 kWh | $122 |
| February | 4.50 m/s | 716 kWh | $121 |
| March | 4.51 m/s | 796 kWh | $135 |
| April | 4.46 m/s | 750 kWh | $127 |
| May | 3.67 m/s | 427 kWh | $72 |
| June | 3.22 m/s | 271 kWh | $46 |
| July | 2.91 m/s | 200 kWh | $34 |
| August | 2.80 m/s | 173 kWh | $29 |
| September | 3.24 m/s | 278 kWh | $47 |
| October | 3.71 m/s | 442 kWh | $75 |
| November | 3.96 m/s | 524 kWh | $89 |
| December | 4.04 m/s | 577 kWh | $98 |
What a taller tower would buy
Measured at 10 m the wind in Carroll County averages 2.53 m/s; at 50 m it is 4.55 m/s. That gives a shear exponent of 0.365, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 3,424 to 9,641 kWh a year, 182% 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 | 3.26 m/s | 3,424 kWh | over 100 years |
| 30 m | 3.78 m/s | 5,505 kWh | over 100 years |
| 40 m | 4.19 m/s | 7,591 kWh | 78 years |
| 50 m | 4.55 m/s | 9,641 kWh | 61 years |
Counties around Carroll County
None of the 6 closest counties is windier than Carroll County.
- Galax city, VA: 3.78 m/s, 5,523 kWh, payback over 100 years (11 mi)
- Surry County, NC: 3.78 m/s, 5,523 kWh, payback over 100 years (22 mi)
- Wythe County, VA: 3.5 m/s, 4,329 kWh, payback over 100 years (23 mi)
- Pulaski County, VA: 3.35 m/s, 3,757 kWh, payback over 100 years (23 mi)
- Patrick County, VA: 3.73 m/s, 5,297 kWh, payback over 100 years (25 mi)
- Floyd County, VA: 3.35 m/s, 3,757 kWh, payback over 100 years (25 mi)
Sun versus wind in Carroll County
Carroll County gets 4.3 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,256 kWh a year; one kW of the turbine above makes 552. Kilowatt for kilowatt, panels make 2.3 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.