Wind Turbine Payback in Millard County, UT
Wind turbine payback in Millard 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 Millard County, UT averages 4.53 m/s (10.1 mph). A 10 kW turbine there would make about 9,519 kWh a year, worth $1,256 at UT's 13.19¢/kWh. Against an installed cost of about $100,000, that is a payback of 80 years, and the turbine is built to last about 20.
What to do in Millard County
A home turbine is not worth buying for savings in Millard County unless your spot is far windier than the county average, 8.7 m/s at the hub against 4.53 m/s here. Per kW, solar panels would make about 1,504 kWh a year here against the turbine's 952, 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 4.53. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of UT
Millard County is the 1,731st 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 Millard County
April is the strongest month here, at 5.28 m/s and about 1,190 kWh. January is the weakest, 3.95 m/s and 538 kWh, so the best month makes 2.2 times the worst. November to March brings in 38% of the year's output in Millard County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.95 m/s | 538 kWh | $71 |
| February | 4.53 m/s | 731 kWh | $96 |
| March | 4.99 m/s | 1,057 kWh | $139 |
| April | 5.28 m/s | 1,190 kWh | $157 |
| May | 4.66 m/s | 874 kWh | $115 |
| June | 5.00 m/s | 1,028 kWh | $136 |
| July | 4.31 m/s | 698 kWh | $92 |
| August | 4.49 m/s | 786 kWh | $104 |
| September | 4.36 m/s | 701 kWh | $92 |
| October | 4.24 m/s | 664 kWh | $88 |
| November | 4.28 m/s | 663 kWh | $87 |
| December | 4.31 m/s | 698 kWh | $92 |
What a taller tower would buy
Measured at 10 m the wind in Millard County averages 3.56 m/s; at 50 m it is 5.07 m/s. That gives a shear exponent of 0.220, typical of ordinary open country. Going from 20 m to 50 m takes output from 7,324 to 13,010 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 | 4.14 m/s | 7,324 kWh | over 100 years |
| 30 m | 4.53 m/s | 9,526 kWh | 80 years |
| 40 m | 4.83 m/s | 11,388 kWh | 67 years |
| 50 m | 5.07 m/s | 13,010 kWh | 58 years |
Counties around Millard County
2 of the 6 closest counties are windier at turbine height; the windiest, Iron County, averages 5.21 m/s.
- Beaver County, UT: 4.7 m/s, 10,571 kWh, payback 72 years (42 mi)
- Juab County, UT: 4.18 m/s, 7,515 kWh, payback over 100 years (55 mi)
- Piute County, UT: 4.02 m/s, 6,678 kWh, payback over 100 years (69 mi)
- Sevier County, UT: 4.02 m/s, 6,678 kWh, payback over 100 years (73 mi)
- Iron County, UT: 5.21 m/s, 13,976 kWh, payback 54 years (73 mi)
- Sanpete County, UT: 3.92 m/s, 6,182 kWh, payback over 100 years (88 mi)
Sun versus wind in Millard County
Millard County gets 5.15 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,504 kWh a year; one kW of the turbine above makes 952. Kilowatt for kilowatt, panels make 1.6 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.