Wind Turbine Payback in San Patricio County, TX
Wind turbine payback in San Patricio 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 San Patricio 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 San Patricio County
A home turbine is not worth buying for savings in San Patricio 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 1,405 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
San Patricio 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 San Patricio County
April is the strongest month here, at 6.70 m/s and about 2,047 kWh. September is the weakest, 5.04 m/s and 1,054 kWh, so the best month makes 1.9 times the worst. November to March brings in 45% of the year's output in San Patricio County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.08 m/s | 1,727 kWh | $277 |
| February | 6.26 m/s | 1,662 kWh | $266 |
| March | 6.45 m/s | 1,959 kWh | $314 |
| April | 6.70 m/s | 2,047 kWh | $328 |
| May | 6.49 m/s | 1,981 kWh | $318 |
| June | 5.77 m/s | 1,480 kWh | $237 |
| July | 5.54 m/s | 1,384 kWh | $222 |
| August | 5.05 m/s | 1,094 kWh | $175 |
| September | 5.04 m/s | 1,054 kWh | $169 |
| October | 5.55 m/s | 1,395 kWh | $224 |
| November | 5.81 m/s | 1,507 kWh | $242 |
| December | 5.93 m/s | 1,631 kWh | $261 |
What a taller tower would buy
Measured at 10 m the wind in San Patricio County averages 4.68 m/s; at 50 m it is 6.55 m/s. That gives a shear exponent of 0.209, typical of ordinary open country. Going from 20 m to 50 m takes output from 15,379 to 23,775 kWh a year, 55% 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 | 5.41 m/s | 15,379 kWh | 41 years |
| 30 m | 5.89 m/s | 18,866 kWh | 33 years |
| 40 m | 6.25 m/s | 21,570 kWh | 29 years |
| 50 m | 6.55 m/s | 23,775 kWh | 26 years |
Counties around San Patricio County
3 of the 6 closest counties are windier at turbine height; the windiest, Aransas County, averages 6.47 m/s.
- Nueces County, TX: 6.18 m/s, 21,039 kWh, payback 30 years (19 mi)
- Refugio County, TX: 5.79 m/s, 18,153 kWh, payback 34 years (30 mi)
- Bee County, TX: 5.6 m/s, 16,762 kWh, payback 37 years (31 mi)
- Aransas County, TX: 6.47 m/s, 23,186 kWh, payback 27 years (34 mi)
- Jim Wells County, TX: 5.85 m/s, 18,595 kWh, payback 34 years (40 mi)
- Kleberg County, TX: 6.18 m/s, 21,039 kWh, payback 30 years (41 mi)
Sun versus wind in San Patricio County
San Patricio 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 1,889. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.3 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.