Wind Turbine Payback in Tom Green County, TX
Wind turbine payback in Tom Green 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 Tom Green County, TX averages 6.28 m/s (14 mph). A 10 kW turbine there would make about 21,781 kWh a year, worth $3,491 at TX's 16.03¢/kWh. Against an installed cost of about $100,000, that is a payback of 29 years, and the turbine is built to last about 20.
What to do in Tom Green County
A home turbine is not worth buying for savings in Tom Green County unless your spot is far windier than the county average, 7.6 m/s at the hub against 6.28 m/s here. Per kW, solar panels would make about 1,524 kWh a year here against the turbine's 2,178, so get a solar quote first.
What would have to change
- Power would have to cost 23¢/kWh, 1.4 times what TX pays now.
- Or the average wind at the hub would have to be 7.6 m/s instead of 6.28. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of TX
Tom Green County is the 498th 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 Tom Green County
April is the strongest month here, at 7.16 m/s and about 2,315 kWh. September is the weakest, 5.45 m/s and 1,289 kWh, so the best month makes 1.8 times the worst. November to March brings in 44% of the year's output in Tom Green County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.32 m/s | 1,874 kWh | $300 |
| February | 6.57 m/s | 1,834 kWh | $294 |
| March | 6.86 m/s | 2,214 kWh | $355 |
| April | 7.16 m/s | 2,315 kWh | $371 |
| May | 6.67 m/s | 2,092 kWh | $335 |
| June | 6.35 m/s | 1,835 kWh | $294 |
| July | 5.71 m/s | 1,492 kWh | $239 |
| August | 5.46 m/s | 1,338 kWh | $214 |
| September | 5.45 m/s | 1,289 kWh | $207 |
| October | 6.18 m/s | 1,790 kWh | $287 |
| November | 6.37 m/s | 1,846 kWh | $296 |
| December | 6.30 m/s | 1,863 kWh | $299 |
What a taller tower would buy
Measured at 10 m the wind in Tom Green County averages 4.93 m/s; at 50 m it is 7.03 m/s. That gives a shear exponent of 0.220, typical of ordinary open country. Going from 20 m to 50 m takes output from 17,833 to 27,257 kWh a year, 53% 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 | 5.75 m/s | 17,833 kWh | 35 years |
| 30 m | 6.28 m/s | 21,801 kWh | 29 years |
| 40 m | 6.69 m/s | 24,825 kWh | 25 years |
| 50 m | 7.03 m/s | 27,257 kWh | 23 years |
Counties around Tom Green County
3 of the 6 closest counties are windier at turbine height; the windiest, Irion County, averages 6.51 m/s.
- Irion County, TX: 6.51 m/s, 23,481 kWh, payback 27 years (31 mi)
- Coke County, TX: 6.25 m/s, 21,558 kWh, payback 29 years (35 mi)
- Schleicher County, TX: 6.39 m/s, 22,595 kWh, payback 28 years (35 mi)
- Concho County, TX: 6.07 m/s, 20,223 kWh, payback 31 years (36 mi)
- Runnels County, TX: 6.15 m/s, 20,816 kWh, payback 30 years (42 mi)
- Sterling County, TX: 6.38 m/s, 22,521 kWh, payback 28 years (46 mi)
Sun versus wind in Tom Green County
Tom Green County gets 5.22 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,524 kWh a year; one kW of the turbine above makes 2,178. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.4 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.