Wind Turbine Payback in Yellowstone County, MT
Wind turbine payback in Yellowstone 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 Yellowstone County, MT averages 5.74 m/s (12.8 mph). A 10 kW turbine there would make about 17,785 kWh a year, worth $2,513 at MT's 14.13¢/kWh. Against an installed cost of about $100,000, that is a payback of 40 years, and the turbine is built to last about 20.
What to do in Yellowstone County
A home turbine is not worth buying for savings in Yellowstone County unless your spot is far windier than the county average, 8.2 m/s at the hub against 5.74 m/s here. Per kW, solar panels would make about 1,203 kWh a year here against the turbine's 1,779, so get a solar quote first.
What would have to change
- Power would have to cost 28¢/kWh, 2.0 times what MT pays now.
- Or the average wind at the hub would have to be 8.2 m/s instead of 5.74. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of MT
Yellowstone County is the 1,116th 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 Yellowstone County
January is the strongest month here, at 6.90 m/s and about 2,236 kWh. July is the weakest, 4.60 m/s and 846 kWh, so the best month makes 2.6 times the worst. November to March brings in 53% of the year's output in Yellowstone County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.90 m/s | 2,236 kWh | $316 |
| February | 6.15 m/s | 1,595 kWh | $225 |
| March | 5.95 m/s | 1,643 kWh | $232 |
| April | 5.73 m/s | 1,455 kWh | $206 |
| May | 5.40 m/s | 1,302 kWh | $184 |
| June | 5.04 m/s | 1,051 kWh | $149 |
| July | 4.60 m/s | 846 kWh | $120 |
| August | 4.69 m/s | 893 kWh | $126 |
| September | 5.18 m/s | 1,131 kWh | $160 |
| October | 6.02 m/s | 1,687 kWh | $238 |
| November | 6.60 m/s | 1,983 kWh | $280 |
| December | 6.59 m/s | 2,044 kWh | $289 |
What a taller tower would buy
Measured at 10 m the wind in Yellowstone County averages 4.43 m/s; at 50 m it is 6.47 m/s. That gives a shear exponent of 0.235, typical of ordinary open country. Going from 20 m to 50 m takes output from 14,023 to 23,186 kWh a year, 65% 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 | 5.22 m/s | 14,023 kWh | 51 years |
| 30 m | 5.74 m/s | 17,771 kWh | 40 years |
| 40 m | 6.14 m/s | 20,738 kWh | 34 years |
| 50 m | 6.47 m/s | 23,186 kWh | 31 years |
Counties around Yellowstone County
3 of the 6 closest counties are windier at turbine height; the windiest, Golden Valley County, averages 6 m/s.
- Musselshell County, MT: 5.95 m/s, 19,334 kWh, payback 37 years (40 mi)
- Big Horn County, MT: 5.44 m/s, 15,605 kWh, payback 45 years (52 mi)
- Treasure County, MT: 5.74 m/s, 17,785 kWh, payback 40 years (52 mi)
- Golden Valley County, MT: 6 m/s, 19,704 kWh, payback 36 years (53 mi)
- Stillwater County, MT: 5.8 m/s, 18,226 kWh, payback 39 years (57 mi)
- Carbon County, MT: 4.41 m/s, 8,807 kWh, payback 80 years (61 mi)
Sun versus wind in Yellowstone County
Yellowstone County gets 4.12 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,203 kWh a year; one kW of the turbine above makes 1,779. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.5 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.