TurbinePayback

Wind Turbine Payback in King George County, VA

Wind turbine payback in King George 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 King George County, VA averages 4.04 m/s (9 mph). A 10 kW turbine there would make about 6,780 kWh a year, worth $1,149 at VA's 16.95¢/kWh. Against an installed cost of about $100,000, that is a payback of 87 years, and the turbine is built to last about 20.

What to do in King George County

A home turbine is not worth buying for savings in King George County unless your spot is far windier than the county average, 7.3 m/s at the hub against 4.04 m/s here. Per kW, solar panels would make about 1,203 kWh a year here against the turbine's 678, so get a solar quote first.

What would have to change

Against the rest of VA

King George County is the 2,033rd 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 King George County

March is the strongest month here, at 4.77 m/s and about 937 kWh. August is the weakest, 3.06 m/s and 237 kWh, so the best month makes 4.0 times the worst. November to March brings in 58% of the year's output in King George County.

MonthWind at 30 mOutputWorth
January4.70 m/s896 kWh$152
February4.81 m/s863 kWh$146
March4.77 m/s937 kWh$159
April4.54 m/s789 kWh$134
May3.80 m/s477 kWh$81
June3.43 m/s332 kWh$56
July3.07 m/s239 kWh$41
August3.06 m/s237 kWh$40
September3.55 m/s371 kWh$63
October4.04 m/s574 kWh$97
November4.31 m/s675 kWh$114
December4.38 m/s735 kWh$125

What a taller tower would buy

Measured at 10 m the wind in King George County averages 2.82 m/s; at 50 m it is 4.77 m/s. That gives a shear exponent of 0.327, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 4,469 to 11,018 kWh a year, 147% more, before counting the extra cost of the taller tower. Why tower height decides it explains the shear behind these numbers.

Hub heightAverage windOutputPayback
20 m3.54 m/s4,469 kWhover 100 years
30 m4.04 m/s6,761 kWh87 years
40 m4.43 m/s8,949 kWh66 years
50 m4.77 m/s11,018 kWh54 years

Counties around King George County

None of the 6 closest counties is windier than King George County.

Sun versus wind in King George County

King George 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 678. Kilowatt for kilowatt, panels make 1.8 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.