Wind Turbine Payback in Madison County, MT
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, MT averages 4.63 m/s (10.4 mph). A 10 kW turbine there would make about 10,132 kWh a year, worth $1,432 at MT's 14.13¢/kWh. Against an installed cost of about $100,000, that is a payback of 70 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, 8.2 m/s at the hub against 4.63 m/s here. Per kW, solar panels would make about 1,197 kWh a year here against the turbine's 1,013, so get a solar quote first.
What would have to change
- Power would have to cost 49¢/kWh, 3.5 times what MT pays now.
- Or the average wind at the hub would have to be 8.2 m/s instead of 4.63. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of MT
Madison County is the 1,671st windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in MT is Fallon County at 6.64 m/s, payback 29 years.
Month by month in Madison County
January is the strongest month here, at 6.00 m/s and about 1,674 kWh. July is the weakest, 3.40 m/s and 336 kWh, so the best month makes 5.0 times the worst. November to March brings in 64% of the year's output in Madison County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.00 m/s | 1,674 kWh | $237 |
| February | 5.31 m/s | 1,126 kWh | $159 |
| March | 5.21 m/s | 1,188 kWh | $168 |
| April | 4.47 m/s | 752 kWh | $106 |
| May | 3.86 m/s | 499 kWh | $71 |
| June | 3.82 m/s | 469 kWh | $66 |
| July | 3.40 m/s | 336 kWh | $47 |
| August | 3.49 m/s | 365 kWh | $52 |
| September | 3.93 m/s | 511 kWh | $72 |
| October | 4.72 m/s | 906 kWh | $128 |
| November | 5.58 m/s | 1,368 kWh | $193 |
| December | 5.81 m/s | 1,552 kWh | $219 |
What a taller tower would buy
Measured at 10 m the wind in Madison County averages 3.57 m/s; at 50 m it is 5.22 m/s. That gives a shear exponent of 0.236, typical of ordinary open country. Going from 20 m to 50 m takes output from 7,650 to 14,046 kWh a year, 84% 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 | 4.2 m/s | 7,650 kWh | 93 years |
| 30 m | 4.63 m/s | 10,115 kWh | 70 years |
| 40 m | 4.95 m/s | 12,214 kWh | 58 years |
| 50 m | 5.22 m/s | 14,046 kWh | 50 years |
Counties around Madison County
1 of the 6 closest counties is windier at turbine height; the windiest, Park County, averages 4.68 m/s.
- Gallatin County, MT: 4.18 m/s, 7,515 kWh, payback 94 years (39 mi)
- Beaverhead County, MT: 3.95 m/s, 6,329 kWh, payback over 100 years (49 mi)
- Silver Bow County, MT: 3.78 m/s, 5,523 kWh, payback over 100 years (53 mi)
- Jefferson County, MT: 4.03 m/s, 6,729 kWh, payback over 100 years (56 mi)
- Park County, MT: 4.68 m/s, 10,445 kWh, payback 68 years (68 mi)
- Broadwater County, MT: 3.97 m/s, 6,428 kWh, payback over 100 years (72 mi)
Sun versus wind in Madison County
Madison County gets 4.1 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,197 kWh a year; one kW of the turbine above makes 1,013. Kilowatt for kilowatt, panels make 1.2 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.