Wind Turbine Payback in Fremont County, ID
Wind turbine payback in Fremont 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 Fremont County, ID averages 4.12 m/s (9.2 mph). A 10 kW turbine there would make about 7,195 kWh a year, worth $937 at ID's 13.02¢/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 Fremont County
A home turbine is not worth buying for savings in Fremont County unless your spot is far windier than the county average, 8.7 m/s at the hub against 4.12 m/s here. Per kW, solar panels would make about 1,226 kWh a year here against the turbine's 720, so get a solar quote first.
What would have to change
- Power would have to cost 69¢/kWh, 5.3 times what ID pays now.
- Or the average wind at the hub would have to be 8.7 m/s instead of 4.12. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of ID
Fremont County is the 1,987th 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 Fremont County
March is the strongest month here, at 4.50 m/s and about 793 kWh. August is the weakest, 3.90 m/s and 518 kWh, so the best month makes 1.5 times the worst. November to March brings in 45% of the year's output in Fremont County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 4.12 m/s | 609 kWh | $79 |
| February | 4.30 m/s | 625 kWh | $81 |
| March | 4.50 m/s | 793 kWh | $103 |
| April | 4.30 m/s | 670 kWh | $87 |
| May | 3.94 m/s | 532 kWh | $69 |
| June | 4.16 m/s | 608 kWh | $79 |
| July | 3.95 m/s | 539 kWh | $70 |
| August | 3.90 m/s | 518 kWh | $67 |
| September | 3.96 m/s | 525 kWh | $68 |
| October | 4.00 m/s | 557 kWh | $73 |
| November | 4.12 m/s | 593 kWh | $77 |
| December | 4.19 m/s | 644 kWh | $84 |
What a taller tower would buy
Measured at 10 m the wind in Fremont County averages 2.93 m/s; at 50 m it is 4.82 m/s. That gives a shear exponent of 0.309, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 4,869 to 11,341 kWh a year, 133% 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 | 3.63 m/s | 4,869 kWh | over 100 years |
| 30 m | 4.12 m/s | 7,175 kWh | over 100 years |
| 40 m | 4.5 m/s | 9,332 kWh | 82 years |
| 50 m | 4.82 m/s | 11,341 kWh | 68 years |
Counties around Fremont County
2 of the 6 closest counties are windier at turbine height; the windiest, Bonneville County, averages 5.09 m/s.
- Madison County, ID: 4.39 m/s, 8,690 kWh, payback 88 years (31 mi)
- Teton County, ID: 4.12 m/s, 7,195 kWh, payback over 100 years (34 mi)
- Clark County, ID: 3.94 m/s, 6,280 kWh, payback over 100 years (43 mi)
- Jefferson County, ID: 3.91 m/s, 6,134 kWh, payback over 100 years (51 mi)
- Teton County, WY: 3.63 m/s, 4,862 kWh, payback over 100 years (54 mi)
- Bonneville County, ID: 5.09 m/s, 13,146 kWh, payback 58 years (57 mi)
Sun versus wind in Fremont County
Fremont County gets 4.2 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,226 kWh a year; one kW of the turbine above makes 720. 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.