Wind Turbine Payback in San Juan County, UT
Wind turbine payback in San Juan 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 Juan County, UT averages 4.51 m/s (10.1 mph). A 10 kW turbine there would make about 9,399 kWh a year, worth $1,240 at UT's 13.19¢/kWh. Against an installed cost of about $100,000, that is a payback of 81 years, and the turbine is built to last about 20.
What to do in San Juan County
A home turbine is not worth buying for savings in San Juan County unless your spot is far windier than the county average, 8.7 m/s at the hub against 4.51 m/s here. Per kW, solar panels would make about 1,577 kWh a year here against the turbine's 940, so get a solar quote first.
What would have to change
- Power would have to cost 53¢/kWh, 4.0 times what UT pays now.
- Or the average wind at the hub would have to be 8.7 m/s instead of 4.51. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of UT
San Juan County is the 1,741st windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in UT is Daggett County at 5.32 m/s, payback 51 years.
Month by month in San Juan County
April is the strongest month here, at 5.49 m/s and about 1,313 kWh. August is the weakest, 3.72 m/s and 448 kWh, so the best month makes 2.9 times the worst. November to March brings in 40% of the year's output in San Juan County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 4.22 m/s | 656 kWh | $87 |
| February | 4.57 m/s | 748 kWh | $99 |
| March | 4.94 m/s | 1,028 kWh | $136 |
| April | 5.49 m/s | 1,313 kWh | $173 |
| May | 4.97 m/s | 1,048 kWh | $138 |
| June | 4.94 m/s | 1,000 kWh | $132 |
| July | 3.98 m/s | 548 kWh | $72 |
| August | 3.72 m/s | 448 kWh | $59 |
| September | 4.20 m/s | 626 kWh | $83 |
| October | 4.46 m/s | 773 kWh | $102 |
| November | 4.44 m/s | 739 kWh | $97 |
| December | 4.22 m/s | 656 kWh | $87 |
What a taller tower would buy
Measured at 10 m the wind in San Juan County averages 3.57 m/s; at 50 m it is 5.02 m/s. That gives a shear exponent of 0.212, typical of ordinary open country. Going from 20 m to 50 m takes output from 7,268 to 12,670 kWh a year, 74% 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 | 4.13 m/s | 7,268 kWh | over 100 years |
| 30 m | 4.5 m/s | 9,367 kWh | 81 years |
| 40 m | 4.79 m/s | 11,134 kWh | 68 years |
| 50 m | 5.02 m/s | 12,670 kWh | 60 years |
Counties around San Juan County
2 of the 6 closest counties are windier at turbine height; the windiest, Wayne County, averages 4.68 m/s.
- Montezuma County, CO: 4.23 m/s, 7,787 kWh, payback 76 years (68 mi)
- Dolores County, CO: 4.23 m/s, 7,787 kWh, payback 76 years (71 mi)
- Wayne County, UT: 4.68 m/s, 10,445 kWh, payback 73 years (80 mi)
- San Miguel County, CO: 3.84 m/s, 5,800 kWh, payback over 100 years (80 mi)
- Garfield County, UT: 4.66 m/s, 10,320 kWh, payback 74 years (92 mi)
- Grand County, UT: 4.35 m/s, 8,460 kWh, payback 90 years (96 mi)
Sun versus wind in San Juan County
San Juan County gets 5.4 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,577 kWh a year; one kW of the turbine above makes 940. Kilowatt for kilowatt, panels make 1.7 times as much here as the turbine. 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.