Wind Turbine Payback in Dimmit County, TX
Wind turbine payback in Dimmit 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 Dimmit County, TX averages 5.36 m/s (12 mph). A 10 kW turbine there would make about 15,034 kWh a year, worth $2,410 at TX's 16.03¢/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 Dimmit County
A home turbine is not worth buying for savings in Dimmit County unless your spot is far windier than the county average, 7.6 m/s at the hub against 5.36 m/s here. Per kW, solar panels would make about 1,457 kWh a year here against the turbine's 1,503, so get a solar quote first.
What would have to change
- Power would have to cost 33¢/kWh, 2.1 times what TX pays now.
- Or the average wind at the hub would have to be 7.6 m/s instead of 5.36. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of TX
Dimmit County is the 1,301st 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 Dimmit County
May is the strongest month here, at 5.90 m/s and about 1,608 kWh. December is the weakest, 4.80 m/s and 951 kWh, so the best month makes 1.7 times the worst. November to March brings in 36% of the year's output in Dimmit County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 4.86 m/s | 986 kWh | $158 |
| February | 5.16 m/s | 1,043 kWh | $167 |
| March | 5.65 m/s | 1,452 kWh | $233 |
| April | 5.91 m/s | 1,567 kWh | $251 |
| May | 5.90 m/s | 1,608 kWh | $258 |
| June | 5.88 m/s | 1,545 kWh | $248 |
| July | 5.73 m/s | 1,502 kWh | $241 |
| August | 5.35 m/s | 1,272 kWh | $204 |
| September | 4.87 m/s | 959 kWh | $154 |
| October | 5.16 m/s | 1,160 kWh | $186 |
| November | 5.01 m/s | 1,037 kWh | $166 |
| December | 4.80 m/s | 951 kWh | $152 |
What a taller tower would buy
Measured at 10 m the wind in Dimmit County averages 4.19 m/s; at 50 m it is 6.01 m/s. That gives a shear exponent of 0.224, typical of ordinary open country. Going from 20 m to 50 m takes output from 11,832 to 19,778 kWh a year, 67% 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 | 4.89 m/s | 11,832 kWh | 53 years |
| 30 m | 5.36 m/s | 15,035 kWh | 42 years |
| 40 m | 5.72 m/s | 17,616 kWh | 35 years |
| 50 m | 6.01 m/s | 19,778 kWh | 32 years |
Counties around Dimmit County
3 of the 6 closest counties are windier at turbine height; the windiest, Webb County, averages 5.68 m/s.
- Zavala County, TX: 5.32 m/s, 14,750 kWh, payback 42 years (30 mi)
- Maverick County, TX: 5.24 m/s, 14,186 kWh, payback 44 years (40 mi)
- La Salle County, TX: 5.41 m/s, 15,390 kWh, payback 41 years (41 mi)
- Frio County, TX: 5.29 m/s, 14,538 kWh, payback 43 years (50 mi)
- Webb County, TX: 5.68 m/s, 17,345 kWh, payback 36 years (53 mi)
- Uvalde County, TX: 5.61 m/s, 16,834 kWh, payback 37 years (64 mi)
Sun versus wind in Dimmit County
Dimmit County gets 4.99 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,457 kWh a year; one kW of the turbine above makes 1,503. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.0 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.