Wind Turbine Payback in Roosevelt County, MT
Wind turbine payback in Roosevelt 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 Roosevelt County, MT averages 6.24 m/s (14 mph). A 10 kW turbine there would make about 21,484 kWh a year, worth $3,036 at MT's 14.13¢/kWh. Against an installed cost of about $100,000, that is a payback of 33 years, and the turbine is built to last about 20.
What to do in Roosevelt County
A home turbine is not worth buying for savings in Roosevelt County unless your spot is far windier than the county average, 8.2 m/s at the hub against 6.24 m/s here. Per kW, solar panels would make about 1,159 kWh a year here against the turbine's 2,148, so get a solar quote first.
What would have to change
- Power would have to cost 23¢/kWh, 1.6 times what MT pays now.
- Or the average wind at the hub would have to be 8.2 m/s instead of 6.24. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of MT
Roosevelt County is the 541st 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 Roosevelt County
October is the strongest month here, at 6.62 m/s and about 2,064 kWh. August is the weakest, 5.62 m/s and 1,434 kWh, so the best month makes 1.4 times the worst. November to March brings in 44% of the year's output in Roosevelt County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.53 m/s | 2,009 kWh | $284 |
| February | 5.99 m/s | 1,503 kWh | $212 |
| March | 6.44 m/s | 1,952 kWh | $276 |
| April | 6.59 m/s | 1,976 kWh | $279 |
| May | 6.39 m/s | 1,919 kWh | $271 |
| June | 5.97 m/s | 1,600 kWh | $226 |
| July | 5.62 m/s | 1,434 kWh | $203 |
| August | 5.62 m/s | 1,434 kWh | $203 |
| September | 6.04 m/s | 1,643 kWh | $232 |
| October | 6.62 m/s | 2,064 kWh | $292 |
| November | 6.60 m/s | 1,982 kWh | $280 |
| December | 6.45 m/s | 1,958 kWh | $277 |
What a taller tower would buy
Measured at 10 m the wind in Roosevelt County averages 4.94 m/s; at 50 m it is 6.95 m/s. That gives a shear exponent of 0.212, typical of ordinary open country. Going from 20 m to 50 m takes output from 17,660 to 26,685 kWh a year, 51% 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 | 5.72 m/s | 17,660 kWh | 40 years |
| 30 m | 6.24 m/s | 21,459 kWh | 33 years |
| 40 m | 6.63 m/s | 24,354 kWh | 29 years |
| 50 m | 6.95 m/s | 26,685 kWh | 27 years |
Counties around Roosevelt County
5 of the 6 closest counties are windier at turbine height; the windiest, Daniels County, averages 6.6 m/s.
- Sheridan County, MT: 6.24 m/s, 21,484 kWh, payback 33 years (36 mi)
- Richland County, MT: 6.27 m/s, 21,706 kWh, payback 33 years (40 mi)
- Daniels County, MT: 6.6 m/s, 24,142 kWh, payback 29 years (43 mi)
- McCone County, MT: 6.43 m/s, 22,891 kWh, payback 31 years (57 mi)
- Williams County, ND: 6.33 m/s, 22,151 kWh, payback 36 years (69 mi)
- Dawson County, MT: 6.49 m/s, 23,333 kWh, payback 30 years (70 mi)
Sun versus wind in Roosevelt County
Roosevelt County gets 3.97 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,159 kWh a year; one kW of the turbine above makes 2,148. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.9 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.