Wind Turbine Payback in DeWitt County, TX
Wind turbine payback in DeWitt 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 DeWitt County, TX averages 5.46 m/s (12.2 mph). A 10 kW turbine there would make about 15,749 kWh a year, worth $2,525 at TX's 16.03¢/kWh. Against an installed cost of about $100,000, that is a payback of 40 years, and the turbine is built to last about 20.
What to do in DeWitt County
A home turbine is not worth buying for savings in DeWitt County unless your spot is far windier than the county average, 7.6 m/s at the hub against 5.46 m/s here. Per kW, solar panels would make about 1,402 kWh a year here against the turbine's 1,575, so get a solar quote first.
What would have to change
- Power would have to cost 32¢/kWh, 2.0 times what TX pays now.
- Or the average wind at the hub would have to be 7.6 m/s instead of 5.46. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of TX
DeWitt County is the 1,245th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in TX is Dallam County at 6.82 m/s, payback 24 years.
Month by month in DeWitt County
April is the strongest month here, at 6.22 m/s and about 1,756 kWh. August is the weakest, 4.53 m/s and 811 kWh, so the best month makes 2.2 times the worst. November to March brings in 47% of the year's output in DeWitt County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 5.74 m/s | 1,513 kWh | $243 |
| February | 5.92 m/s | 1,467 kWh | $235 |
| March | 6.07 m/s | 1,719 kWh | $276 |
| April | 6.22 m/s | 1,756 kWh | $281 |
| May | 5.96 m/s | 1,647 kWh | $264 |
| June | 5.17 m/s | 1,129 kWh | $181 |
| July | 4.85 m/s | 983 kWh | $158 |
| August | 4.53 m/s | 811 kWh | $130 |
| September | 4.62 m/s | 830 kWh | $133 |
| October | 5.23 m/s | 1,198 kWh | $192 |
| November | 5.57 m/s | 1,363 kWh | $218 |
| December | 5.67 m/s | 1,469 kWh | $235 |
What a taller tower would buy
Measured at 10 m the wind in DeWitt County averages 4.24 m/s; at 50 m it is 6.14 m/s. That gives a shear exponent of 0.230, typical of ordinary open country. Going from 20 m to 50 m takes output from 12,355 to 20,742 kWh a year, 68% 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 | 4.97 m/s | 12,355 kWh | 51 years |
| 30 m | 5.46 m/s | 15,744 kWh | 40 years |
| 40 m | 5.83 m/s | 18,468 kWh | 34 years |
| 50 m | 6.14 m/s | 20,742 kWh | 30 years |
Counties around DeWitt County
1 of the 6 closest counties is windier at turbine height; the windiest, Goliad County, averages 5.6 m/s.
- Gonzales County, TX: 5.38 m/s, 15,176 kWh, payback 41 years (27 mi)
- Goliad County, TX: 5.6 m/s, 16,762 kWh, payback 37 years (29 mi)
- Victoria County, TX: 5.42 m/s, 15,462 kWh, payback 40 years (31 mi)
- Karnes County, TX: 5.39 m/s, 15,247 kWh, payback 41 years (32 mi)
- Lavaca County, TX: 5.36 m/s, 15,034 kWh, payback 42 years (34 mi)
- Wilson County, TX: 5.39 m/s, 15,247 kWh, payback 41 years (44 mi)
Sun versus wind in DeWitt County
DeWitt County gets 4.8 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,402 kWh a year; one kW of the turbine above makes 1,575. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.1 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.