Wind Turbine Payback in Falls Church city, VA
Wind turbine payback in Falls Church city
No. The turbine wears out before it pays for itself.
At 30 m, the height a home turbine tower usually reaches, the wind in Falls Church city, VA averages 5.23 m/s (11.7 mph). A 10 kW turbine there would make about 14,116 kWh a year, worth $2,393 at VA's 16.95¢/kWh. Against an installed cost of about $100,000, that is a payback of 42 years, and the turbine is built to last about 20.
What to do in Falls Church city
A home turbine is not worth buying for savings in Falls Church city unless your spot is far windier than the county average, 7.3 m/s at the hub against 5.23 m/s here. Per kW, solar panels would make about 1,203 kWh a year here against the turbine's 1,412, so get a solar quote first.
What would have to change
- Power would have to cost 35¢/kWh, 2.1 times what VA pays now.
- Or the average wind at the hub would have to be 7.3 m/s instead of 5.23. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of VA
Falls Church city is the 1,360th 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 Falls Church city
March is the strongest month here, at 6.14 m/s and about 1,764 kWh. August is the weakest, 3.91 m/s and 520 kWh, so the best month makes 3.4 times the worst. November to March brings in 56% of the year's output in Falls Church city.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.06 m/s | 1,714 kWh | $291 |
| February | 6.15 m/s | 1,598 kWh | $271 |
| March | 6.14 m/s | 1,764 kWh | $299 |
| April | 5.89 m/s | 1,551 kWh | $263 |
| May | 4.95 m/s | 1,034 kWh | $175 |
| June | 4.44 m/s | 736 kWh | $125 |
| July | 3.93 m/s | 531 kWh | $90 |
| August | 3.91 m/s | 520 kWh | $88 |
| September | 4.57 m/s | 801 kWh | $136 |
| October | 5.30 m/s | 1,240 kWh | $210 |
| November | 5.69 m/s | 1,434 kWh | $243 |
| December | 5.76 m/s | 1,526 kWh | $259 |
What a taller tower would buy
Measured at 10 m the wind in Falls Church city averages 3.97 m/s; at 50 m it is 5.94 m/s. That gives a shear exponent of 0.250, typical of ordinary open country. Going from 20 m to 50 m takes output from 10,723 to 19,260 kWh a year, 80% 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 | 4.72 m/s | 10,723 kWh | 55 years |
| 30 m | 5.23 m/s | 14,101 kWh | 42 years |
| 40 m | 5.62 m/s | 16,891 kWh | 35 years |
| 50 m | 5.94 m/s | 19,260 kWh | 31 years |
Counties around Falls Church city
None of the 6 closest counties is windier than Falls Church city.
- Arlington County, VA: 5.23 m/s, 14,116 kWh, payback 42 years (4 mi)
- Fairfax County, VA: 4.57 m/s, 9,763 kWh, payback 60 years (6 mi)
- Alexandria city, VA: 5.23 m/s, 14,116 kWh, payback 42 years (7 mi)
- Fairfax city, VA: 4.57 m/s, 9,763 kWh, payback 60 years (7 mi)
- District of Columbia, DC: 5.23 m/s, 14,116 kWh, payback 29 years (9 mi)
- Manassas Park city, VA: 4.57 m/s, 9,763 kWh, payback 60 years (16 mi)
Sun versus wind in Falls Church city
Falls Church city 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 1,412. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.2 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.