Wind Turbine Payback in Isle of Wight County, VA
Wind turbine payback in Isle of Wight 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 Isle of Wight County, VA averages 4.22 m/s (9.4 mph). A 10 kW turbine there would make about 7,732 kWh a year, worth $1,311 at VA's 16.95¢/kWh. Against an installed cost of about $100,000, that is a payback of 76 years, and the turbine is built to last about 20.
What to do in Isle of Wight County
A home turbine is not worth buying for savings in Isle of Wight County unless your spot is far windier than the county average, 7.3 m/s at the hub against 4.22 m/s here. Per kW, solar panels would make about 1,270 kWh a year here against the turbine's 773, so get a solar quote first.
What would have to change
- Power would have to cost 65¢/kWh, 3.8 times what VA pays now.
- Or the average wind at the hub would have to be 7.3 m/s instead of 4.22. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of VA
Isle of Wight County is the 1,935th 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 Isle of Wight County
March is the strongest month here, at 4.85 m/s and about 981 kWh. August is the weakest, 3.36 m/s and 322 kWh, so the best month makes 3.0 times the worst. November to March brings in 52% of the year's output in Isle of Wight County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 4.64 m/s | 867 kWh | $147 |
| February | 4.79 m/s | 857 kWh | $145 |
| March | 4.85 m/s | 981 kWh | $166 |
| April | 4.85 m/s | 949 kWh | $161 |
| May | 4.21 m/s | 651 kWh | $110 |
| June | 3.72 m/s | 432 kWh | $73 |
| July | 3.50 m/s | 369 kWh | $63 |
| August | 3.36 m/s | 322 kWh | $55 |
| September | 3.85 m/s | 482 kWh | $82 |
| October | 4.13 m/s | 616 kWh | $104 |
| November | 4.36 m/s | 699 kWh | $118 |
| December | 4.42 m/s | 755 kWh | $128 |
What a taller tower would buy
Measured at 10 m the wind in Isle of Wight County averages 2.89 m/s; at 50 m it is 5.04 m/s. That gives a shear exponent of 0.346, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 5,037 to 12,805 kWh a year, 154% 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 | 3.67 m/s | 5,037 kWh | over 100 years |
| 30 m | 4.22 m/s | 7,751 kWh | 76 years |
| 40 m | 4.67 m/s | 10,354 kWh | 57 years |
| 50 m | 5.04 m/s | 12,805 kWh | 46 years |
Counties around Isle of Wight County
5 of the 6 closest counties are windier at turbine height; the windiest, Newport News city, averages 5.92 m/s.
- Suffolk city, VA: 5.06 m/s, 12,941 kWh, payback 46 years (15 mi)
- Newport News city, VA: 5.92 m/s, 19,112 kWh, payback 31 years (16 mi)
- Surry County, VA: 4.22 m/s, 7,732 kWh, payback 76 years (18 mi)
- Portsmouth city, VA: 5.92 m/s, 19,112 kWh, payback 31 years (20 mi)
- Franklin city, VA: 5.06 m/s, 12,941 kWh, payback 46 years (20 mi)
- Hampton city, VA: 5.92 m/s, 19,112 kWh, payback 31 years (25 mi)
Sun versus wind in Isle of Wight County
Isle of Wight 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 773. Kilowatt for kilowatt, panels make 1.6 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.