Wind Turbine Payback in Davis County, UT
Wind turbine payback in Davis 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 Davis County, UT averages 3.95 m/s (8.8 mph). A 10 kW turbine there would make about 6,329 kWh a year, worth $835 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 Davis County
A home turbine is not worth buying for savings in Davis County unless your spot is far windier than the county average, 8.7 m/s at the hub against 3.95 m/s here. Per kW, solar panels would make about 1,358 kWh a year here against the turbine's 633, so get a solar quote first.
What would have to change
- Power would have to cost 79¢/kWh, 6.0 times what UT pays now.
- Or the average wind at the hub would have to be 8.7 m/s instead of 3.95. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of UT
Davis County is the 2,089th 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 Davis County
April is the strongest month here, at 4.67 m/s and about 853 kWh. January is the weakest, 3.48 m/s and 360 kWh, so the best month makes 2.4 times the worst. November to March brings in 42% of the year's output in Davis County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.48 m/s | 360 kWh | $47 |
| February | 4.16 m/s | 567 kWh | $75 |
| March | 4.50 m/s | 794 kWh | $105 |
| April | 4.67 m/s | 853 kWh | $113 |
| May | 4.02 m/s | 566 kWh | $75 |
| June | 4.06 m/s | 567 kWh | $75 |
| July | 3.52 m/s | 373 kWh | $49 |
| August | 3.70 m/s | 439 kWh | $58 |
| September | 3.78 m/s | 452 kWh | $60 |
| October | 3.83 m/s | 489 kWh | $64 |
| November | 3.83 m/s | 474 kWh | $63 |
| December | 3.92 m/s | 527 kWh | $70 |
What a taller tower would buy
Measured at 10 m the wind in Davis County averages 3.38 m/s; at 50 m it is 4.25 m/s. That gives a shear exponent of 0.142, typical of very open, smooth ground where height adds little. Going from 20 m to 50 m takes output from 5,304 to 7,897 kWh a year, 49% 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 | 3.73 m/s | 5,304 kWh | over 100 years |
| 30 m | 3.95 m/s | 6,342 kWh | over 100 years |
| 40 m | 4.12 m/s | 7,182 kWh | over 100 years |
| 50 m | 4.25 m/s | 7,897 kWh | 96 years |
Counties around Davis County
2 of the 6 closest counties are windier at turbine height; the windiest, Box Elder County, averages 4.17 m/s.
- Weber County, UT: 3.08 m/s, 2,844 kWh, payback over 100 years (23 mi)
- Salt Lake County, UT: 3.41 m/s, 3,980 kWh, payback over 100 years (29 mi)
- Morgan County, UT: 3.22 m/s, 3,299 kWh, payback over 100 years (33 mi)
- Cache County, UT: 3.08 m/s, 2,844 kWh, payback over 100 years (54 mi)
- Box Elder County, UT: 4.17 m/s, 7,461 kWh, payback over 100 years (60 mi)
- Tooele County, UT: 4.13 m/s, 7,248 kWh, payback over 100 years (62 mi)
Sun versus wind in Davis County
Davis County gets 4.65 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,358 kWh a year; one kW of the turbine above makes 633. Kilowatt for kilowatt, panels make 2.1 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.