Wind Turbine Payback in Bonneville County, ID
Wind turbine payback in Bonneville 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 Bonneville County, ID averages 5.09 m/s (11.4 mph). A 10 kW turbine there would make about 13,146 kWh a year, worth $1,712 at ID's 13.02¢/kWh. Against an installed cost of about $100,000, that is a payback of 58 years, and the turbine is built to last about 20.
What to do in Bonneville County
A home turbine is not worth buying for savings in Bonneville County unless your spot is far windier than the county average, 8.7 m/s at the hub against 5.09 m/s here. Per kW, solar panels would make about 1,288 kWh a year here against the turbine's 1,315, so get a solar quote first.
What would have to change
- Power would have to cost 38¢/kWh, 2.9 times what ID pays now.
- Or the average wind at the hub would have to be 8.7 m/s instead of 5.09. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of ID
Bonneville County is the 1,408th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in ID is Owyhee County at 5.38 m/s, payback 51 years.
Month by month in Bonneville County
March is the strongest month here, at 5.75 m/s and about 1,515 kWh. August is the weakest, 4.63 m/s and 858 kWh, so the best month makes 1.8 times the worst. November to March brings in 47% of the year's output in Bonneville County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 5.15 m/s | 1,150 kWh | $150 |
| February | 5.39 m/s | 1,172 kWh | $153 |
| March | 5.75 m/s | 1,515 kWh | $197 |
| April | 5.31 m/s | 1,209 kWh | $157 |
| May | 4.86 m/s | 983 kWh | $128 |
| June | 5.09 m/s | 1,078 kWh | $140 |
| July | 4.69 m/s | 891 kWh | $116 |
| August | 4.63 m/s | 858 kWh | $112 |
| September | 4.76 m/s | 899 kWh | $117 |
| October | 5.00 m/s | 1,063 kWh | $138 |
| November | 5.22 m/s | 1,153 kWh | $150 |
| December | 5.23 m/s | 1,197 kWh | $156 |
What a taller tower would buy
Measured at 10 m the wind in Bonneville County averages 3.89 m/s; at 50 m it is 5.76 m/s. That gives a shear exponent of 0.244, typical of ordinary open country. Going from 20 m to 50 m takes output from 9,984 to 17,932 kWh a year, 80% 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 | 4.61 m/s | 9,984 kWh | 77 years |
| 30 m | 5.09 m/s | 13,112 kWh | 59 years |
| 40 m | 5.45 m/s | 15,711 kWh | 49 years |
| 50 m | 5.76 m/s | 17,932 kWh | 43 years |
Counties around Bonneville County
None of the 6 closest counties is windier than Bonneville County.
- Madison County, ID: 4.39 m/s, 8,690 kWh, payback 88 years (27 mi)
- Teton County, ID: 4.12 m/s, 7,195 kWh, payback over 100 years (33 mi)
- Bingham County, ID: 4.82 m/s, 11,341 kWh, payback 68 years (41 mi)
- Caribou County, ID: 3.51 m/s, 4,368 kWh, payback over 100 years (42 mi)
- Jefferson County, ID: 3.91 m/s, 6,134 kWh, payback over 100 years (45 mi)
- Fremont County, ID: 4.12 m/s, 7,195 kWh, payback over 100 years (57 mi)
Sun versus wind in Bonneville County
Bonneville County gets 4.41 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,288 kWh a year; one kW of the turbine above makes 1,315. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.0 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.