Wind Turbine Payback in Fallon County, MT
Wind turbine payback in Fallon 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 Fallon County, MT averages 6.64 m/s (14.9 mph). A 10 kW turbine there would make about 24,436 kWh a year, worth $3,453 at MT's 14.13¢/kWh. Against an installed cost of about $100,000, that is a payback of 29 years, and the turbine is built to last about 20.
What to do in Fallon County
A home turbine is not worth buying for savings in Fallon County unless your spot is far windier than the county average, 8.2 m/s at the hub against 6.64 m/s here. Per kW, solar panels would make about 1,209 kWh a year here against the turbine's 2,444, so get a solar quote first.
What would have to change
- Power would have to cost 20¢/kWh, 1.4 times what MT pays now.
- Or the average wind at the hub would have to be 8.2 m/s instead of 6.64. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of MT
Fallon County is the 97th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. It is the windiest county in MT.
Month by month in Fallon County
January is the strongest month here, at 7.23 m/s and about 2,435 kWh. July is the weakest, 5.81 m/s and 1,557 kWh, so the best month makes 1.6 times the worst. November to March brings in 46% of the year's output in Fallon County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 7.23 m/s | 2,435 kWh | $344 |
| February | 6.56 m/s | 1,831 kWh | $259 |
| March | 6.85 m/s | 2,206 kWh | $312 |
| April | 6.80 m/s | 2,103 kWh | $297 |
| May | 6.56 m/s | 2,027 kWh | $286 |
| June | 6.21 m/s | 1,748 kWh | $247 |
| July | 5.81 m/s | 1,557 kWh | $220 |
| August | 5.92 m/s | 1,625 kWh | $230 |
| September | 6.42 m/s | 1,875 kWh | $265 |
| October | 7.03 m/s | 2,316 kWh | $327 |
| November | 7.11 m/s | 2,289 kWh | $323 |
| December | 7.05 m/s | 2,327 kWh | $329 |
What a taller tower would buy
Measured at 10 m the wind in Fallon County averages 5.31 m/s; at 50 m it is 7.36 m/s. That gives a shear exponent of 0.203, typical of ordinary open country. Going from 20 m to 50 m takes output from 20,525 to 29,576 kWh a year, 44% 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 | 6.11 m/s | 20,525 kWh | 35 years |
| 30 m | 6.64 m/s | 24,399 kWh | 29 years |
| 40 m | 7.03 m/s | 27,286 kWh | 26 years |
| 50 m | 7.36 m/s | 29,576 kWh | 24 years |
Counties around Fallon County
3 of the 6 closest counties are windier at turbine height; the windiest, Bowman County, averages 6.79 m/s.
- Wibaux County, MT: 6.43 m/s, 22,891 kWh, payback 31 years (45 mi)
- Bowman County, ND: 6.79 m/s, 25,529 kWh, payback 31 years (45 mi)
- Slope County, ND: 6.78 m/s, 25,457 kWh, payback 32 years (46 mi)
- Golden Valley County, ND: 6.68 m/s, 24,728 kWh, payback 33 years (50 mi)
- Custer County, MT: 6.09 m/s, 20,371 kWh, payback 35 years (55 mi)
- Carter County, MT: 6.54 m/s, 23,702 kWh, payback 30 years (56 mi)
Sun versus wind in Fallon County
Fallon County gets 4.14 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,209 kWh a year; one kW of the turbine above makes 2,444. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 2.0 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.