Wind Turbine Payback in Coryell County, TX
Wind turbine payback in Coryell 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 Coryell County, TX averages 5.69 m/s (12.7 mph). A 10 kW turbine there would make about 17,419 kWh a year, worth $2,792 at TX's 16.03¢/kWh. Against an installed cost of about $100,000, that is a payback of 36 years, and the turbine is built to last about 20.
What to do in Coryell County
A home turbine is not worth buying for savings in Coryell County unless your spot is far windier than the county average, 7.6 m/s at the hub against 5.69 m/s here. Per kW, solar panels would make about 1,405 kWh a year here against the turbine's 1,742, so get a solar quote first.
What would have to change
- Power would have to cost 29¢/kWh, 1.8 times what TX pays now.
- Or the average wind at the hub would have to be 7.6 m/s instead of 5.69. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of TX
Coryell County is the 1,136th 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 Coryell County
April is the strongest month here, at 6.56 m/s and about 1,960 kWh. September is the weakest, 4.61 m/s and 822 kWh, so the best month makes 2.4 times the worst. November to March brings in 49% of the year's output in Coryell County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.08 m/s | 1,724 kWh | $276 |
| February | 6.28 m/s | 1,669 kWh | $268 |
| March | 6.39 m/s | 1,920 kWh | $308 |
| April | 6.56 m/s | 1,960 kWh | $314 |
| May | 5.94 m/s | 1,635 kWh | $262 |
| June | 5.37 m/s | 1,243 kWh | $199 |
| July | 4.94 m/s | 1,029 kWh | $165 |
| August | 4.68 m/s | 887 kWh | $142 |
| September | 4.61 m/s | 822 kWh | $132 |
| October | 5.50 m/s | 1,360 kWh | $218 |
| November | 5.96 m/s | 1,593 kWh | $255 |
| December | 6.00 m/s | 1,674 kWh | $268 |
What a taller tower would buy
Measured at 10 m the wind in Coryell County averages 4.39 m/s; at 50 m it is 6.42 m/s. That gives a shear exponent of 0.236, typical of ordinary open country. Going from 20 m to 50 m takes output from 13,709 to 22,817 kWh a year, 66% 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 | 5.17 m/s | 13,709 kWh | 46 years |
| 30 m | 5.69 m/s | 17,425 kWh | 36 years |
| 40 m | 6.09 m/s | 20,376 kWh | 31 years |
| 50 m | 6.42 m/s | 22,817 kWh | 27 years |
Counties around Coryell County
4 of the 6 closest counties are windier at turbine height; the windiest, Mills County, averages 5.87 m/s.
- Hamilton County, TX: 5.82 m/s, 18,374 kWh, payback 34 years (29 mi)
- Lampasas County, TX: 5.75 m/s, 17,859 kWh, payback 35 years (29 mi)
- Bell County, TX: 5.61 m/s, 16,834 kWh, payback 37 years (30 mi)
- Bosque County, TX: 5.75 m/s, 17,859 kWh, payback 35 years (36 mi)
- McLennan County, TX: 5.69 m/s, 17,419 kWh, payback 36 years (37 mi)
- Mills County, TX: 5.87 m/s, 18,742 kWh, payback 33 years (48 mi)
Sun versus wind in Coryell County
Coryell County gets 4.81 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,405 kWh a year; one kW of the turbine above makes 1,742. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.2 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.