Wind Turbine Payback in Coke County, TX
Wind turbine payback in Coke 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 Coke County, TX averages 6.25 m/s (14 mph). A 10 kW turbine there would make about 21,558 kWh a year, worth $3,456 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 Coke County
A home turbine is not worth buying for savings in Coke County unless your spot is far windier than the county average, 7.6 m/s at the hub against 6.25 m/s here. Per kW, solar panels would make about 1,524 kWh a year here against the turbine's 2,156, 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 6.25. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of TX
Coke County is the 528th 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 Coke County
April is the strongest month here, at 7.15 m/s and about 2,309 kWh. September is the weakest, 5.45 m/s and 1,290 kWh, so the best month makes 1.8 times the worst. November to March brings in 44% of the year's output in Coke County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.26 m/s | 1,840 kWh | $295 |
| February | 6.51 m/s | 1,799 kWh | $288 |
| March | 6.83 m/s | 2,191 kWh | $351 |
| April | 7.15 m/s | 2,309 kWh | $370 |
| May | 6.63 m/s | 2,069 kWh | $332 |
| June | 6.35 m/s | 1,835 kWh | $294 |
| July | 5.65 m/s | 1,454 kWh | $233 |
| August | 5.41 m/s | 1,306 kWh | $209 |
| September | 5.45 m/s | 1,290 kWh | $207 |
| October | 6.16 m/s | 1,772 kWh | $284 |
| November | 6.33 m/s | 1,819 kWh | $292 |
| December | 6.26 m/s | 1,834 kWh | $294 |
What a taller tower would buy
Measured at 10 m the wind in Coke County averages 4.89 m/s; at 50 m it is 7 m/s. That gives a shear exponent of 0.223, typical of ordinary open country. Going from 20 m to 50 m takes output from 17,538 to 27,043 kWh a year, 54% 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 | 5.71 m/s | 17,538 kWh | 36 years |
| 30 m | 6.25 m/s | 21,531 kWh | 29 years |
| 40 m | 6.66 m/s | 24,583 kWh | 25 years |
| 50 m | 7 m/s | 27,043 kWh | 23 years |
Counties around Coke County
5 of the 6 closest counties are windier at turbine height; the windiest, Irion County, averages 6.51 m/s.
- Sterling County, TX: 6.38 m/s, 22,521 kWh, payback 28 years (25 mi)
- Nolan County, TX: 6.33 m/s, 22,151 kWh, payback 28 years (33 mi)
- Mitchell County, TX: 6.33 m/s, 22,151 kWh, payback 28 years (34 mi)
- Tom Green County, TX: 6.28 m/s, 21,781 kWh, payback 29 years (35 mi)
- Runnels County, TX: 6.15 m/s, 20,816 kWh, payback 30 years (38 mi)
- Irion County, TX: 6.51 m/s, 23,481 kWh, payback 27 years (45 mi)
Sun versus wind in Coke County
Coke 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 2,156. 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.