Wind Turbine Payback in Caroline County, VA
Wind turbine payback in Caroline 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 Caroline County, VA averages 3.26 m/s (7.3 mph). A 10 kW turbine there would make about 3,436 kWh a year, worth $582 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 Caroline County
A home turbine is not worth buying for savings in Caroline County unless your spot is far windier than the county average, 7.3 m/s at the hub against 3.26 m/s here. Per kW, solar panels would make about 1,203 kWh a year here against the turbine's 344, so get a solar quote first.
What would have to change
- Power would have to cost 146¢/kWh, 8.6 times what VA pays now.
- Or the average wind at the hub would have to be 7.3 m/s instead of 3.26. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of VA
Caroline County is the 2,801st 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 Caroline County
March is the strongest month here, at 3.82 m/s and about 486 kWh. August is the weakest, 2.55 m/s and 123 kWh, so the best month makes 4.0 times the worst. November to March brings in 55% of the year's output in Caroline County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.66 m/s | 425 kWh | $72 |
| February | 3.81 m/s | 436 kWh | $74 |
| March | 3.82 m/s | 486 kWh | $82 |
| April | 3.74 m/s | 437 kWh | $74 |
| May | 3.16 m/s | 263 kWh | $45 |
| June | 2.86 m/s | 182 kWh | $31 |
| July | 2.62 m/s | 137 kWh | $23 |
| August | 2.55 m/s | 123 kWh | $21 |
| September | 2.90 m/s | 191 kWh | $32 |
| October | 3.24 m/s | 285 kWh | $48 |
| November | 3.42 m/s | 330 kWh | $56 |
| December | 3.40 m/s | 336 kWh | $57 |
What a taller tower would buy
Measured at 10 m the wind in Caroline County averages 1.97 m/s; at 50 m it is 4.12 m/s. That gives a shear exponent of 0.458, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 1,816 to 7,195 kWh a year, 296% 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 | 2.71 m/s | 1,816 kWh | over 100 years |
| 30 m | 3.26 m/s | 3,438 kWh | over 100 years |
| 40 m | 3.72 m/s | 5,252 kWh | over 100 years |
| 50 m | 4.12 m/s | 7,195 kWh | 82 years |
Counties around Caroline County
4 of the 6 closest counties are windier at turbine height; the windiest, King George County, averages 4.04 m/s.
- Spotsylvania County, VA: 3.26 m/s, 3,436 kWh, payback over 100 years (20 mi)
- Hanover County, VA: 3.26 m/s, 3,436 kWh, payback over 100 years (20 mi)
- Fredericksburg city, VA: 3.65 m/s, 4,948 kWh, payback over 100 years (20 mi)
- King George County, VA: 4.04 m/s, 6,780 kWh, payback 87 years (20 mi)
- Essex County, VA: 3.63 m/s, 4,862 kWh, payback over 100 years (24 mi)
- King William County, VA: 3.77 m/s, 5,477 kWh, payback over 100 years (26 mi)
Sun versus wind in Caroline County
Caroline County gets 4.12 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,203 kWh a year; one kW of the turbine above makes 344. 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.