Wind Turbine Payback in Rosebud County, MT
Wind turbine payback in Rosebud 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 Rosebud County, MT averages 5.92 m/s (13.2 mph). A 10 kW turbine there would make about 19,112 kWh a year, worth $2,701 at MT's 14.13¢/kWh. Against an installed cost of about $100,000, that is a payback of 37 years, and the turbine is built to last about 20.
What to do in Rosebud County
A home turbine is not worth buying for savings in Rosebud County unless your spot is far windier than the county average, 8.2 m/s at the hub against 5.92 m/s here. Per kW, solar panels would make about 1,197 kWh a year here against the turbine's 1,911, so get a solar quote first.
What would have to change
- Power would have to cost 26¢/kWh, 1.9 times what MT pays now.
- Or the average wind at the hub would have to be 8.2 m/s instead of 5.92. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of MT
Rosebud County is the 959th 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 Rosebud County
January is the strongest month here, at 6.84 m/s and about 2,199 kWh. July is the weakest, 4.99 m/s and 1,061 kWh, so the best month makes 2.1 times the worst. November to March brings in 50% of the year's output in Rosebud County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.84 m/s | 2,199 kWh | $311 |
| February | 6.15 m/s | 1,594 kWh | $225 |
| March | 6.10 m/s | 1,737 kWh | $245 |
| April | 5.91 m/s | 1,567 kWh | $221 |
| May | 5.76 m/s | 1,524 kWh | $215 |
| June | 5.42 m/s | 1,272 kWh | $180 |
| July | 4.99 m/s | 1,061 kWh | $150 |
| August | 5.10 m/s | 1,123 kWh | $159 |
| September | 5.47 m/s | 1,299 kWh | $184 |
| October | 6.19 m/s | 1,793 kWh | $253 |
| November | 6.57 m/s | 1,968 kWh | $278 |
| December | 6.57 m/s | 2,034 kWh | $287 |
What a taller tower would buy
Measured at 10 m the wind in Rosebud County averages 4.63 m/s; at 50 m it is 6.64 m/s. That gives a shear exponent of 0.224, typical of ordinary open country. Going from 20 m to 50 m takes output from 15,375 to 24,436 kWh a year, 59% 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 | 5.41 m/s | 15,375 kWh | 46 years |
| 30 m | 5.92 m/s | 19,127 kWh | 37 years |
| 40 m | 6.32 m/s | 22,049 kWh | 32 years |
| 50 m | 6.64 m/s | 24,436 kWh | 29 years |
Counties around Rosebud County
4 of the 6 closest counties are windier at turbine height; the windiest, Garfield County, averages 6.41 m/s.
- Treasure County, MT: 5.74 m/s, 17,785 kWh, payback 40 years (29 mi)
- Custer County, MT: 6.09 m/s, 20,371 kWh, payback 35 years (54 mi)
- Big Horn County, MT: 5.44 m/s, 15,605 kWh, payback 45 years (67 mi)
- Prairie County, MT: 6.37 m/s, 22,447 kWh, payback 32 years (71 mi)
- Powder River County, MT: 6.12 m/s, 20,594 kWh, payback 34 years (75 mi)
- Garfield County, MT: 6.41 m/s, 22,743 kWh, payback 31 years (77 mi)
Sun versus wind in Rosebud County
Rosebud 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 1,911. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.6 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.