Wind Turbine Payback in Franklin County, VA
Wind turbine payback in Franklin 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 Franklin County, VA averages 3.3 m/s (7.4 mph). A 10 kW turbine there would make about 3,577 kWh a year, worth $606 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 Franklin County
A home turbine is not worth buying for savings in Franklin County unless your spot is far windier than the county average, 7.3 m/s at the hub against 3.3 m/s here. Per kW, solar panels would make about 1,267 kWh a year here against the turbine's 358, so get a solar quote first.
What would have to change
- Power would have to cost 140¢/kWh, 8.2 times what VA pays now.
- Or the average wind at the hub would have to be 7.3 m/s instead of 3.3. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of VA
Franklin County is the 2,741st 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 Franklin County
January is the strongest month here, at 3.95 m/s and about 537 kWh. August is the weakest, 2.44 m/s and 105 kWh, so the best month makes 5.1 times the worst. November to March brings in 61% of the year's output in Franklin County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.95 m/s | 537 kWh | $91 |
| February | 4.05 m/s | 522 kWh | $88 |
| March | 3.93 m/s | 531 kWh | $90 |
| April | 3.81 m/s | 464 kWh | $79 |
| May | 3.11 m/s | 248 kWh | $42 |
| June | 2.79 m/s | 165 kWh | $28 |
| July | 2.53 m/s | 120 kWh | $20 |
| August | 2.44 m/s | 105 kWh | $18 |
| September | 2.73 m/s | 154 kWh | $26 |
| October | 3.19 m/s | 270 kWh | $46 |
| November | 3.48 m/s | 349 kWh | $59 |
| December | 3.63 m/s | 413 kWh | $70 |
What a taller tower would buy
Measured at 10 m the wind in Franklin County averages 2.02 m/s; at 50 m it is 4.14 m/s. That gives a shear exponent of 0.446, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 1,923 to 7,301 kWh a year, 280% 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 | 2.75 m/s | 1,923 kWh | over 100 years |
| 30 m | 3.3 m/s | 3,564 kWh | over 100 years |
| 40 m | 3.75 m/s | 5,377 kWh | over 100 years |
| 50 m | 4.14 m/s | 7,301 kWh | 81 years |
Counties around Franklin County
3 of the 6 closest counties are windier at turbine height; the windiest, Martinsville city, averages 3.73 m/s.
- Roanoke city, VA: 3.19 m/s, 3,198 kWh, payback over 100 years (20 mi)
- Martinsville city, VA: 3.73 m/s, 5,297 kWh, payback over 100 years (21 mi)
- Salem city, VA: 3.19 m/s, 3,198 kWh, payback over 100 years (22 mi)
- Floyd County, VA: 3.35 m/s, 3,757 kWh, payback over 100 years (26 mi)
- Henry County, VA: 3.73 m/s, 5,297 kWh, payback over 100 years (26 mi)
- Roanoke County, VA: 3.19 m/s, 3,198 kWh, payback over 100 years (29 mi)
Sun versus wind in Franklin County
Franklin County gets 4.34 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,267 kWh a year; one kW of the turbine above makes 358. Kilowatt for kilowatt, panels make 3.5 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.