Wind Turbine Payback in Terrell County, TX
Wind turbine payback in Terrell 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 Terrell County, TX averages 5.56 m/s (12.4 mph). A 10 kW turbine there would make about 16,471 kWh a year, worth $2,640 at TX's 16.03¢/kWh. Against an installed cost of about $100,000, that is a payback of 38 years, and the turbine is built to last about 20.
What to do in Terrell County
A home turbine is not worth buying for savings in Terrell County unless your spot is far windier than the county average, 7.6 m/s at the hub against 5.56 m/s here. Per kW, solar panels would make about 1,621 kWh a year here against the turbine's 1,647, so get a solar quote first.
What would have to change
- Power would have to cost 30¢/kWh, 1.9 times what TX pays now.
- Or the average wind at the hub would have to be 7.6 m/s instead of 5.56. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of TX
Terrell County is the 1,181st 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 Terrell County
April is the strongest month here, at 6.14 m/s and about 1,706 kWh. November is the weakest, 5.12 m/s and 1,096 kWh, so the best month makes 1.6 times the worst. November to March brings in 37% of the year's output in Terrell County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 5.15 m/s | 1,154 kWh | $185 |
| February | 5.50 m/s | 1,232 kWh | $197 |
| March | 5.76 m/s | 1,525 kWh | $244 |
| April | 6.14 m/s | 1,706 kWh | $273 |
| May | 6.03 m/s | 1,694 kWh | $272 |
| June | 6.13 m/s | 1,700 kWh | $273 |
| July | 5.79 m/s | 1,542 kWh | $247 |
| August | 5.45 m/s | 1,331 kWh | $213 |
| September | 5.24 m/s | 1,168 kWh | $187 |
| October | 5.32 m/s | 1,255 kWh | $201 |
| November | 5.12 m/s | 1,096 kWh | $176 |
| December | 5.08 m/s | 1,112 kWh | $178 |
What a taller tower would buy
Measured at 10 m the wind in Terrell County averages 4.41 m/s; at 50 m it is 6.19 m/s. That gives a shear exponent of 0.211, typical of ordinary open country. Going from 20 m to 50 m takes output from 13,228 to 21,113 kWh a year, 60% 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 | 5.1 m/s | 13,228 kWh | 47 years |
| 30 m | 5.56 m/s | 16,453 kWh | 38 years |
| 40 m | 5.91 m/s | 19,003 kWh | 33 years |
| 50 m | 6.19 m/s | 21,113 kWh | 30 years |
Counties around Terrell County
5 of the 6 closest counties are windier at turbine height; the windiest, Reagan County, averages 6.51 m/s.
- Crockett County, TX: 6.23 m/s, 21,410 kWh, payback 29 years (52 mi)
- Pecos County, TX: 6.32 m/s, 22,077 kWh, payback 28 years (54 mi)
- Val Verde County, TX: 6.01 m/s, 19,778 kWh, payback 32 years (61 mi)
- Brewster County, TX: 5.11 m/s, 13,284 kWh, payback 47 years (76 mi)
- Upton County, TX: 6.37 m/s, 22,447 kWh, payback 28 years (78 mi)
- Reagan County, TX: 6.51 m/s, 23,481 kWh, payback 27 years (86 mi)
Sun versus wind in Terrell County
Terrell County gets 5.55 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,621 kWh a year; one kW of the turbine above makes 1,647. 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.