Wind Turbine Payback in Grayson County, TX
Wind turbine payback in Grayson 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 Grayson County, TX averages 5.89 m/s (13.2 mph). A 10 kW turbine there would make about 18,890 kWh a year, worth $3,028 at TX's 16.03¢/kWh. Against an installed cost of about $100,000, that is a payback of 33 years, and the turbine is built to last about 20.
What to do in Grayson County
A home turbine is not worth buying for savings in Grayson County unless your spot is far windier than the county average, 7.6 m/s at the hub against 5.89 m/s here. Per kW, solar panels would make about 1,355 kWh a year here against the turbine's 1,889, so get a solar quote first.
What would have to change
- Power would have to cost 26¢/kWh, 1.7 times what TX pays now.
- Or the average wind at the hub would have to be 7.6 m/s instead of 5.89. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of TX
Grayson County is the 1,001st 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 Grayson County
April is the strongest month here, at 6.86 m/s and about 2,139 kWh. August is the weakest, 4.71 m/s and 906 kWh, so the best month makes 2.4 times the worst. November to March brings in 49% of the year's output in Grayson County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.24 m/s | 1,822 kWh | $292 |
| February | 6.44 m/s | 1,762 kWh | $282 |
| March | 6.69 m/s | 2,106 kWh | $338 |
| April | 6.86 m/s | 2,139 kWh | $343 |
| May | 6.12 m/s | 1,749 kWh | $280 |
| June | 5.52 m/s | 1,333 kWh | $214 |
| July | 4.87 m/s | 989 kWh | $159 |
| August | 4.71 m/s | 906 kWh | $145 |
| September | 4.94 m/s | 996 kWh | $160 |
| October | 5.83 m/s | 1,565 kWh | $251 |
| November | 6.30 m/s | 1,801 kWh | $289 |
| December | 6.16 m/s | 1,777 kWh | $285 |
What a taller tower would buy
Measured at 10 m the wind in Grayson County averages 4.58 m/s; at 50 m it is 6.62 m/s. That gives a shear exponent of 0.229, typical of ordinary open country. Going from 20 m to 50 m takes output from 15,083 to 24,289 kWh a year, 61% 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 | 5.37 m/s | 15,083 kWh | 41 years |
| 30 m | 5.89 m/s | 18,884 kWh | 33 years |
| 40 m | 6.29 m/s | 21,856 kWh | 29 years |
| 50 m | 6.62 m/s | 24,289 kWh | 26 years |
Counties around Grayson County
2 of the 6 closest counties are windier at turbine height; the windiest, Marshall County, averages 5.95 m/s.
- Marshall County, OK: 5.95 m/s, 19,334 kWh, payback 38 years (28 mi)
- Collin County, TX: 5.77 m/s, 18,006 kWh, payback 35 years (30 mi)
- Cooke County, TX: 5.91 m/s, 19,038 kWh, payback 33 years (31 mi)
- Fannin County, TX: 5.72 m/s, 17,638 kWh, payback 35 years (33 mi)
- Bryan County, OK: 5.29 m/s, 14,538 kWh, payback 50 years (33 mi)
- Denton County, TX: 5.77 m/s, 18,006 kWh, payback 35 years (39 mi)
Sun versus wind in Grayson County
Grayson County gets 4.64 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,355 kWh a year; one kW of the turbine above makes 1,889. 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.