Wind Turbine Payback in Bexar County, TX
Wind turbine payback in Bexar 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 Bexar County, TX averages 5.38 m/s (12 mph). A 10 kW turbine there would make about 15,176 kWh a year, worth $2,433 at TX's 16.03¢/kWh. Against an installed cost of about $100,000, that is a payback of 41 years, and the turbine is built to last about 20.
What to do in Bexar County
A home turbine is not worth buying for savings in Bexar County unless your spot is far windier than the county average, 7.6 m/s at the hub against 5.38 m/s here. Per kW, solar panels would make about 1,413 kWh a year here against the turbine's 1,518, so get a solar quote first.
What would have to change
- Power would have to cost 33¢/kWh, 2.1 times what TX pays now.
- Or the average wind at the hub would have to be 7.6 m/s instead of 5.38. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of TX
Bexar County is the 1,292nd 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 Bexar County
April is the strongest month here, at 6.02 m/s and about 1,630 kWh. September is the weakest, 4.66 m/s and 847 kWh, so the best month makes 1.9 times the worst. November to March brings in 46% of the year's output in Bexar County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 5.53 m/s | 1,379 kWh | $221 |
| February | 5.70 m/s | 1,340 kWh | $215 |
| March | 5.87 m/s | 1,595 kWh | $256 |
| April | 6.02 m/s | 1,630 kWh | $261 |
| May | 5.76 m/s | 1,522 kWh | $244 |
| June | 5.25 m/s | 1,173 kWh | $188 |
| July | 4.88 m/s | 996 kWh | $160 |
| August | 4.64 m/s | 865 kWh | $139 |
| September | 4.66 m/s | 847 kWh | $136 |
| October | 5.22 m/s | 1,191 kWh | $191 |
| November | 5.49 m/s | 1,313 kWh | $210 |
| December | 5.49 m/s | 1,357 kWh | $218 |
What a taller tower would buy
Measured at 10 m the wind in Bexar County averages 4.17 m/s; at 50 m it is 6.05 m/s. That gives a shear exponent of 0.231, typical of ordinary open country. Going from 20 m to 50 m takes output from 11,839 to 20,075 kWh a year, 70% 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 | 4.9 m/s | 11,839 kWh | 53 years |
| 30 m | 5.38 m/s | 15,152 kWh | 41 years |
| 40 m | 5.75 m/s | 17,830 kWh | 35 years |
| 50 m | 6.05 m/s | 20,075 kWh | 31 years |
Counties around Bexar County
4 of the 6 closest counties are windier at turbine height; the windiest, Kendall County, averages 5.75 m/s.
- Comal County, TX: 5.56 m/s, 16,471 kWh, payback 38 years (30 mi)
- Wilson County, TX: 5.39 m/s, 15,247 kWh, payback 41 years (32 mi)
- Guadalupe County, TX: 5.35 m/s, 14,963 kWh, payback 42 years (36 mi)
- Kendall County, TX: 5.75 m/s, 17,859 kWh, payback 35 years (36 mi)
- Medina County, TX: 5.43 m/s, 15,534 kWh, payback 40 years (36 mi)
- Atascosa County, TX: 5.31 m/s, 14,679 kWh, payback 43 years (39 mi)
Sun versus wind in Bexar County
Bexar County gets 4.84 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,413 kWh a year; one kW of the turbine above makes 1,518. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.1 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.