Wind Turbine Payback in Powder River County, MT
Wind turbine payback in Powder River 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 Powder River County, MT averages 6.12 m/s (13.7 mph). A 10 kW turbine there would make about 20,594 kWh a year, worth $2,910 at MT's 14.13¢/kWh. Against an installed cost of about $100,000, that is a payback of 34 years, and the turbine is built to last about 20.
What to do in Powder River County
A home turbine is not worth buying for savings in Powder River County unless your spot is far windier than the county average, 8.2 m/s at the hub against 6.12 m/s here. Per kW, solar panels would make about 1,235 kWh a year here against the turbine's 2,059, so get a solar quote first.
What would have to change
- Power would have to cost 24¢/kWh, 1.7 times what MT pays now.
- Or the average wind at the hub would have to be 8.2 m/s instead of 6.12. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of MT
Powder River County is the 664th 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 Powder River County
January is the strongest month here, at 6.85 m/s and about 2,205 kWh. July is the weakest, 5.28 m/s and 1,231 kWh, so the best month makes 1.8 times the worst. November to March brings in 47% of the year's output in Powder River County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.85 m/s | 2,205 kWh | $312 |
| February | 6.28 m/s | 1,669 kWh | $236 |
| March | 6.35 m/s | 1,893 kWh | $267 |
| April | 6.20 m/s | 1,739 kWh | $246 |
| May | 6.03 m/s | 1,690 kWh | $239 |
| June | 5.66 m/s | 1,414 kWh | $200 |
| July | 5.28 m/s | 1,231 kWh | $174 |
| August | 5.36 m/s | 1,280 kWh | $181 |
| September | 5.80 m/s | 1,500 kWh | $212 |
| October | 6.44 m/s | 1,949 kWh | $275 |
| November | 6.51 m/s | 1,930 kWh | $273 |
| December | 6.60 m/s | 2,050 kWh | $290 |
What a taller tower would buy
Measured at 10 m the wind in Powder River County averages 4.81 m/s; at 50 m it is 6.84 m/s. That gives a shear exponent of 0.219, typical of ordinary open country. Going from 20 m to 50 m takes output from 16,735 to 25,892 kWh a year, 55% 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 | 5.6 m/s | 16,735 kWh | 42 years |
| 30 m | 6.12 m/s | 20,565 kWh | 34 years |
| 40 m | 6.51 m/s | 23,509 kWh | 30 years |
| 50 m | 6.84 m/s | 25,892 kWh | 27 years |
Counties around Powder River County
2 of the 6 closest counties are windier at turbine height; the windiest, Fallon County, averages 6.64 m/s.
- Carter County, MT: 6.54 m/s, 23,702 kWh, payback 30 years (51 mi)
- Custer County, MT: 6.09 m/s, 20,371 kWh, payback 35 years (59 mi)
- Crook County, WY: 5.61 m/s, 16,834 kWh, payback 42 years (74 mi)
- Rosebud County, MT: 5.92 m/s, 19,112 kWh, payback 37 years (75 mi)
- Sheridan County, WY: 5.63 m/s, 16,980 kWh, payback 42 years (78 mi)
- Fallon County, MT: 6.64 m/s, 24,436 kWh, payback 29 years (84 mi)
Sun versus wind in Powder River County
Powder River County gets 4.23 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,235 kWh a year; one kW of the turbine above makes 2,059. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.7 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.