Wind Turbine Payback in Southampton County, VA
Wind turbine payback in Southampton 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 Southampton County, VA averages 5.06 m/s (11.3 mph). A 10 kW turbine there would make about 12,941 kWh a year, worth $2,194 at VA's 16.95¢/kWh. Against an installed cost of about $100,000, that is a payback of 46 years, and the turbine is built to last about 20.
What to do in Southampton County
A home turbine is not worth buying for savings in Southampton County unless your spot is far windier than the county average, 7.3 m/s at the hub against 5.06 m/s here. Per kW, solar panels would make about 1,270 kWh a year here against the turbine's 1,294, so get a solar quote first.
What would have to change
- Power would have to cost 39¢/kWh, 2.3 times what VA pays now.
- Or the average wind at the hub would have to be 7.3 m/s instead of 5.06. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of VA
Southampton County is the 1,422nd 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 Southampton County
March is the strongest month here, at 5.78 m/s and about 1,538 kWh. August is the weakest, 4.03 m/s and 573 kWh, so the best month makes 2.7 times the worst. November to March brings in 50% of the year's output in Southampton County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 5.50 m/s | 1,360 kWh | $231 |
| February | 5.67 m/s | 1,326 kWh | $225 |
| March | 5.78 m/s | 1,538 kWh | $261 |
| April | 5.85 m/s | 1,526 kWh | $259 |
| May | 5.13 m/s | 1,141 kWh | $193 |
| June | 4.49 m/s | 761 kWh | $129 |
| July | 4.27 m/s | 680 kWh | $115 |
| August | 4.03 m/s | 573 kWh | $97 |
| September | 4.68 m/s | 858 kWh | $145 |
| October | 4.94 m/s | 1,030 kWh | $175 |
| November | 5.20 m/s | 1,144 kWh | $194 |
| December | 5.27 m/s | 1,223 kWh | $207 |
What a taller tower would buy
Measured at 10 m the wind in Southampton County averages 3.76 m/s; at 50 m it is 5.81 m/s. That gives a shear exponent of 0.270, typical of ordinary open country. Going from 20 m to 50 m takes output from 9,559 to 18,300 kWh a year, 91% 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 | 4.54 m/s | 9,559 kWh | 62 years |
| 30 m | 5.06 m/s | 12,952 kWh | 46 years |
| 40 m | 5.47 m/s | 15,823 kWh | 37 years |
| 50 m | 5.81 m/s | 18,300 kWh | 32 years |
Counties around Southampton County
None of the 6 closest counties is windier than Southampton County.
- Franklin city, VA: 5.06 m/s, 12,941 kWh, payback 46 years (9 mi)
- Sussex County, VA: 3.25 m/s, 3,402 kWh, payback over 100 years (17 mi)
- Emporia city, VA: 3.99 m/s, 6,527 kWh, payback 90 years (24 mi)
- Isle of Wight County, VA: 4.22 m/s, 7,732 kWh, payback 76 years (25 mi)
- Greensville County, VA: 3.99 m/s, 6,527 kWh, payback 90 years (25 mi)
- Hertford County, NC: 5.06 m/s, 12,941 kWh, payback 52 years (26 mi)
Sun versus wind in Southampton County
Southampton County gets 4.35 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,270 kWh a year; one kW of the turbine above makes 1,294. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.0 times. 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.