Wind Turbine Payback in Robertson County, TX
Wind turbine payback in Robertson 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 Robertson County, TX averages 5.27 m/s (11.8 mph). A 10 kW turbine there would make about 14,397 kWh a year, worth $2,308 at TX's 16.03¢/kWh. Against an installed cost of about $100,000, that is a payback of 43 years, and the turbine is built to last about 20.
What to do in Robertson County
A home turbine is not worth buying for savings in Robertson County unless your spot is far windier than the county average, 7.6 m/s at the hub against 5.27 m/s here. Per kW, solar panels would make about 1,381 kWh a year here against the turbine's 1,440, so get a solar quote first.
What would have to change
- Power would have to cost 35¢/kWh, 2.2 times what TX pays now.
- Or the average wind at the hub would have to be 7.6 m/s instead of 5.27. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of TX
Robertson County is the 1,333rd 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 Robertson County
March is the strongest month here, at 6.01 m/s and about 1,677 kWh. August is the weakest, 4.26 m/s and 676 kWh, so the best month makes 2.5 times the worst. November to March brings in 51% of the year's output in Robertson County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 5.73 m/s | 1,506 kWh | $241 |
| February | 5.96 m/s | 1,490 kWh | $239 |
| March | 6.01 m/s | 1,677 kWh | $269 |
| April | 6.02 m/s | 1,634 kWh | $262 |
| May | 5.49 m/s | 1,359 kWh | $218 |
| June | 4.74 m/s | 888 kWh | $142 |
| July | 4.41 m/s | 749 kWh | $120 |
| August | 4.26 m/s | 676 kWh | $108 |
| September | 4.33 m/s | 687 kWh | $110 |
| October | 5.12 m/s | 1,132 kWh | $181 |
| November | 5.60 m/s | 1,378 kWh | $221 |
| December | 5.69 m/s | 1,478 kWh | $237 |
What a taller tower would buy
Measured at 10 m the wind in Robertson County averages 4.01 m/s; at 50 m it is 5.99 m/s. That gives a shear exponent of 0.249, typical of ordinary open country. Going from 20 m to 50 m takes output from 11,005 to 19,630 kWh a year, 78% 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 | 4.77 m/s | 11,005 kWh | 57 years |
| 30 m | 5.27 m/s | 14,429 kWh | 43 years |
| 40 m | 5.67 m/s | 17,245 kWh | 36 years |
| 50 m | 5.99 m/s | 19,630 kWh | 32 years |
Counties around Robertson County
4 of the 6 closest counties are windier at turbine height; the windiest, Falls County, averages 5.52 m/s.
- Brazos County, TX: 4.94 m/s, 12,132 kWh, payback 51 years (28 mi)
- Falls County, TX: 5.52 m/s, 16,181 kWh, payback 39 years (29 mi)
- Milam County, TX: 5.43 m/s, 15,534 kWh, payback 40 years (32 mi)
- Madison County, TX: 4.35 m/s, 8,460 kWh, payback 74 years (35 mi)
- Leon County, TX: 5.43 m/s, 15,534 kWh, payback 40 years (36 mi)
- Limestone County, TX: 5.52 m/s, 16,181 kWh, payback 39 years (36 mi)
Sun versus wind in Robertson County
Robertson County gets 4.73 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,381 kWh a year; one kW of the turbine above makes 1,440. 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.