Wind Turbine Payback in Madison County, ID
Wind turbine payback in Madison 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 Madison County, ID averages 4.39 m/s (9.8 mph). A 10 kW turbine there would make about 8,690 kWh a year, worth $1,131 at ID's 13.02¢/kWh. Against an installed cost of about $100,000, that is a payback of 88 years, and the turbine is built to last about 20.
What to do in Madison County
A home turbine is not worth buying for savings in Madison County unless your spot is far windier than the county average, 8.7 m/s at the hub against 4.39 m/s here. Per kW, solar panels would make about 1,288 kWh a year here against the turbine's 869, so get a solar quote first.
What would have to change
- Power would have to cost 58¢/kWh, 4.4 times what ID pays now.
- Or the average wind at the hub would have to be 8.7 m/s instead of 4.39. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of ID
Madison County is the 1,825th 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 Madison County
March is the strongest month here, at 4.89 m/s and about 1,005 kWh. January is the weakest, 3.95 m/s and 538 kWh, so the best month makes 1.9 times the worst. November to March brings in 40% of the year's output in Madison County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.95 m/s | 538 kWh | $70 |
| February | 4.43 m/s | 683 kWh | $89 |
| March | 4.89 m/s | 1,005 kWh | $131 |
| April | 4.85 m/s | 949 kWh | $124 |
| May | 4.47 m/s | 779 kWh | $101 |
| June | 4.60 m/s | 819 kWh | $107 |
| July | 4.26 m/s | 675 kWh | $88 |
| August | 4.17 m/s | 634 kWh | $83 |
| September | 4.23 m/s | 641 kWh | $83 |
| October | 4.37 m/s | 730 kWh | $95 |
| November | 4.26 m/s | 653 kWh | $85 |
| December | 4.21 m/s | 651 kWh | $85 |
What a taller tower would buy
Measured at 10 m the wind in Madison County averages 3.35 m/s; at 50 m it is 4.98 m/s. That gives a shear exponent of 0.246, typical of ordinary open country. Going from 20 m to 50 m takes output from 6,452 to 12,400 kWh a year, 92% 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 | 3.97 m/s | 6,452 kWh | over 100 years |
| 30 m | 4.39 m/s | 8,701 kWh | 88 years |
| 40 m | 4.71 m/s | 10,660 kWh | 72 years |
| 50 m | 4.98 m/s | 12,400 kWh | 62 years |
Counties around Madison County
2 of the 6 closest counties are windier at turbine height; the windiest, Bonneville County, averages 5.09 m/s.
- Teton County, ID: 4.12 m/s, 7,195 kWh, payback over 100 years (22 mi)
- Bonneville County, ID: 5.09 m/s, 13,146 kWh, payback 58 years (27 mi)
- Fremont County, ID: 4.12 m/s, 7,195 kWh, payback over 100 years (31 mi)
- Jefferson County, ID: 3.91 m/s, 6,134 kWh, payback over 100 years (33 mi)
- Clark County, ID: 3.94 m/s, 6,280 kWh, payback over 100 years (49 mi)
- Bingham County, ID: 4.82 m/s, 11,341 kWh, payback 68 years (54 mi)
Sun versus wind in Madison County
Madison 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 869. Kilowatt for kilowatt, panels make 1.5 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.