Wind Turbine Payback in Mathews County, VA
Wind turbine payback in Mathews 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 Mathews County, VA averages 5.5 m/s (12.3 mph). A 10 kW turbine there would make about 16,037 kWh a year, worth $2,718 at VA's 16.95¢/kWh. Against an installed cost of about $100,000, that is a payback of 37 years, and the turbine is built to last about 20.
What to do in Mathews County
A home turbine is not worth buying for savings in Mathews County unless your spot is far windier than the county average, 7.3 m/s at the hub against 5.5 m/s here. Per kW, solar panels would make about 1,259 kWh a year here against the turbine's 1,604, so get a solar quote first.
What would have to change
- Power would have to cost 31¢/kWh, 1.8 times what VA pays now.
- Or the average wind at the hub would have to be 7.3 m/s instead of 5.5. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of VA
Mathews County is the 1,222nd 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 Mathews County
March is the strongest month here, at 6.30 m/s and about 1,863 kWh. August is the weakest, 4.29 m/s and 690 kWh, so the best month makes 2.7 times the worst. November to March brings in 52% of the year's output in Mathews County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.22 m/s | 1,811 kWh | $307 |
| February | 6.23 m/s | 1,641 kWh | $278 |
| March | 6.30 m/s | 1,863 kWh | $316 |
| April | 6.26 m/s | 1,780 kWh | $302 |
| May | 5.38 m/s | 1,287 kWh | $218 |
| June | 4.75 m/s | 896 kWh | $152 |
| July | 4.43 m/s | 756 kWh | $128 |
| August | 4.29 m/s | 690 kWh | $117 |
| September | 5.04 m/s | 1,054 kWh | $179 |
| October | 5.47 m/s | 1,342 kWh | $227 |
| November | 5.83 m/s | 1,516 kWh | $257 |
| December | 5.96 m/s | 1,646 kWh | $279 |
What a taller tower would buy
Measured at 10 m the wind in Mathews County averages 4.44 m/s; at 50 m it is 6.08 m/s. That gives a shear exponent of 0.195, typical of ordinary open country. Going from 20 m to 50 m takes output from 13,113 to 20,297 kWh a year, 55% 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 | 5.09 m/s | 13,113 kWh | 45 years |
| 30 m | 5.5 m/s | 16,063 kWh | 37 years |
| 40 m | 5.82 m/s | 18,382 kWh | 32 years |
| 50 m | 6.08 m/s | 20,297 kWh | 29 years |
Counties around Mathews County
3 of the 6 closest counties are windier at turbine height; the windiest, Northampton County, averages 7.01 m/s.
- Gloucester County, VA: 5.5 m/s, 16,037 kWh, payback 37 years (14 mi)
- York County, VA: 5.92 m/s, 19,112 kWh, payback 31 years (16 mi)
- Middlesex County, VA: 5.5 m/s, 16,037 kWh, payback 37 years (19 mi)
- Poquoson city, VA: 5.92 m/s, 19,112 kWh, payback 31 years (21 mi)
- Northampton County, VA: 7.01 m/s, 27,114 kWh, payback 22 years (21 mi)
- Lancaster County, VA: 5.5 m/s, 16,037 kWh, payback 37 years (21 mi)
Sun versus wind in Mathews County
Mathews County gets 4.31 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,259 kWh a year; one kW of the turbine above makes 1,604. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.3 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.