Wind Turbine Payback in Sanpete County, UT
Wind turbine payback in Sanpete 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 Sanpete County, UT averages 3.92 m/s (8.8 mph). A 10 kW turbine there would make about 6,182 kWh a year, worth $815 at UT's 13.19¢/kWh. Against an installed cost of about $100,000, that is a payback of over 100 years, and the turbine is built to last about 20.
What to do in Sanpete County
A home turbine is not worth buying for savings in Sanpete County unless your spot is far windier than the county average, 8.7 m/s at the hub against 3.92 m/s here. Per kW, solar panels would make about 1,445 kWh a year here against the turbine's 618, so get a solar quote first.
What would have to change
- Power would have to cost 81¢/kWh, 6.1 times what UT pays now.
- Or the average wind at the hub would have to be 8.7 m/s instead of 3.92. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of UT
Sanpete County is the 2,118th 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 Sanpete County
April is the strongest month here, at 4.51 m/s and about 775 kWh. January is the weakest, 3.61 m/s and 405 kWh, so the best month makes 1.9 times the worst. November to March brings in 38% of the year's output in Sanpete County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.61 m/s | 405 kWh | $53 |
| February | 3.86 m/s | 452 kWh | $60 |
| March | 4.18 m/s | 638 kWh | $84 |
| April | 4.51 m/s | 775 kWh | $102 |
| May | 4.05 m/s | 581 kWh | $77 |
| June | 4.32 m/s | 679 kWh | $90 |
| July | 3.70 m/s | 438 kWh | $58 |
| August | 3.81 m/s | 479 kWh | $63 |
| September | 3.82 m/s | 471 kWh | $62 |
| October | 3.73 m/s | 451 kWh | $59 |
| November | 3.83 m/s | 474 kWh | $63 |
| December | 3.67 m/s | 428 kWh | $56 |
What a taller tower would buy
Measured at 10 m the wind in Sanpete County averages 3.19 m/s; at 50 m it is 4.32 m/s. That gives a shear exponent of 0.188, typical of ordinary open country. Going from 20 m to 50 m takes output from 4,889 to 8,289 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 | 3.64 m/s | 4,889 kWh | over 100 years |
| 30 m | 3.92 m/s | 6,204 kWh | over 100 years |
| 40 m | 4.14 m/s | 7,314 kWh | over 100 years |
| 50 m | 4.32 m/s | 8,289 kWh | 92 years |
Counties around Sanpete County
4 of the 6 closest counties are windier at turbine height; the windiest, Carbon County, averages 4.73 m/s.
- Sevier County, UT: 4.02 m/s, 6,678 kWh, payback over 100 years (45 mi)
- Utah County, UT: 3.6 m/s, 4,736 kWh, payback over 100 years (52 mi)
- Emery County, UT: 4.5 m/s, 9,339 kWh, payback 81 years (52 mi)
- Carbon County, UT: 4.73 m/s, 10,762 kWh, payback 70 years (57 mi)
- Juab County, UT: 4.18 m/s, 7,515 kWh, payback over 100 years (69 mi)
- Wasatch County, UT: 3.18 m/s, 3,165 kWh, payback over 100 years (70 mi)
Sun versus wind in Sanpete County
Sanpete County gets 4.95 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,445 kWh a year; one kW of the turbine above makes 618. Kilowatt for kilowatt, panels make 2.3 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.