Wind Turbine Payback in Big Horn County, MT
Wind turbine payback in Big Horn 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 Big Horn County, MT averages 5.44 m/s (12.2 mph). A 10 kW turbine there would make about 15,605 kWh a year, worth $2,205 at MT's 14.13¢/kWh. Against an installed cost of about $100,000, that is a payback of 45 years, and the turbine is built to last about 20.
What to do in Big Horn County
A home turbine is not worth buying for savings in Big Horn County unless your spot is far windier than the county average, 8.2 m/s at the hub against 5.44 m/s here. Per kW, solar panels would make about 1,229 kWh a year here against the turbine's 1,561, so get a solar quote first.
What would have to change
- Power would have to cost 32¢/kWh, 2.3 times what MT pays now.
- Or the average wind at the hub would have to be 8.2 m/s instead of 5.44. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of MT
Big Horn County is the 1,249th 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 Big Horn County
January is the strongest month here, at 6.51 m/s and about 1,995 kWh. July is the weakest, 4.53 m/s and 807 kWh, so the best month makes 2.5 times the worst. November to March brings in 53% of the year's output in Big Horn County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.51 m/s | 1,995 kWh | $282 |
| February | 5.88 m/s | 1,445 kWh | $204 |
| March | 5.66 m/s | 1,462 kWh | $207 |
| April | 5.39 m/s | 1,251 kWh | $177 |
| May | 5.20 m/s | 1,182 kWh | $167 |
| June | 4.83 m/s | 937 kWh | $132 |
| July | 4.53 m/s | 807 kWh | $114 |
| August | 4.58 m/s | 835 kWh | $118 |
| September | 4.94 m/s | 999 kWh | $141 |
| October | 5.62 m/s | 1,434 kWh | $203 |
| November | 5.97 m/s | 1,602 kWh | $226 |
| December | 6.13 m/s | 1,756 kWh | $248 |
What a taller tower would buy
Measured at 10 m the wind in Big Horn County averages 4.19 m/s; at 50 m it is 6.14 m/s. That gives a shear exponent of 0.237, typical of ordinary open country. Going from 20 m to 50 m takes output from 12,142 to 20,742 kWh a year, 71% 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 | 4.94 m/s | 12,142 kWh | 58 years |
| 30 m | 5.44 m/s | 15,604 kWh | 45 years |
| 40 m | 5.82 m/s | 18,401 kWh | 39 years |
| 50 m | 6.14 m/s | 20,742 kWh | 34 years |
Counties around Big Horn County
4 of the 6 closest counties are windier at turbine height; the windiest, Rosebud County, averages 5.92 m/s.
- Yellowstone County, MT: 5.74 m/s, 17,785 kWh, payback 40 years (52 mi)
- Sheridan County, WY: 5.63 m/s, 16,980 kWh, payback 42 years (53 mi)
- Treasure County, MT: 5.74 m/s, 17,785 kWh, payback 40 years (58 mi)
- Big Horn County, WY: 4.34 m/s, 8,403 kWh, payback 85 years (65 mi)
- Rosebud County, MT: 5.92 m/s, 19,112 kWh, payback 37 years (67 mi)
- Carbon County, MT: 4.41 m/s, 8,807 kWh, payback 80 years (74 mi)
Sun versus wind in Big Horn County
Big Horn County gets 4.21 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,229 kWh a year; one kW of the turbine above makes 1,561. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.3 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.