Wind Turbine Payback in Silver Bow County, MT
Wind turbine payback in Silver Bow 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 Silver Bow County, MT averages 3.78 m/s (8.5 mph). A 10 kW turbine there would make about 5,523 kWh a year, worth $780 at MT's 14.13¢/kWh. Against an installed cost of about $100,000, that is a payback of over 100 years, and the turbine is built to last about 20.
What to do in Silver Bow County
A home turbine is not worth buying for savings in Silver Bow County unless your spot is far windier than the county average, 8.2 m/s at the hub against 3.78 m/s here. Per kW, solar panels would make about 1,232 kWh a year here against the turbine's 552, so get a solar quote first.
What would have to change
- Power would have to cost 91¢/kWh, 6.4 times what MT pays now.
- Or the average wind at the hub would have to be 8.2 m/s instead of 3.78. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of MT
Silver Bow County is the 2,219th 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 Silver Bow County
January is the strongest month here, at 4.61 m/s and about 851 kWh. August is the weakest, 2.98 m/s and 217 kWh, so the best month makes 3.9 times the worst. November to March brings in 60% of the year's output in Silver Bow County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 4.61 m/s | 851 kWh | $120 |
| February | 4.29 m/s | 624 kWh | $88 |
| March | 4.27 m/s | 679 kWh | $96 |
| April | 3.85 m/s | 480 kWh | $68 |
| May | 3.35 m/s | 318 kWh | $45 |
| June | 3.19 m/s | 264 kWh | $37 |
| July | 2.98 m/s | 217 kWh | $31 |
| August | 2.98 m/s | 217 kWh | $31 |
| September | 3.33 m/s | 302 kWh | $43 |
| October | 3.93 m/s | 530 kWh | $75 |
| November | 4.28 m/s | 665 kWh | $94 |
| December | 4.35 m/s | 719 kWh | $102 |
What a taller tower would buy
Measured at 10 m the wind in Silver Bow County averages 2.59 m/s; at 50 m it is 4.51 m/s. That gives a shear exponent of 0.345, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 3,533 to 9,399 kWh a year, 166% 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 | 3.29 m/s | 3,533 kWh | over 100 years |
| 30 m | 3.78 m/s | 5,528 kWh | over 100 years |
| 40 m | 4.18 m/s | 7,493 kWh | 95 years |
| 50 m | 4.51 m/s | 9,399 kWh | 75 years |
Counties around Silver Bow County
4 of the 6 closest counties are windier at turbine height; the windiest, Madison County, averages 4.63 m/s.
- Deer Lodge County, MT: 3.65 m/s, 4,948 kWh, payback over 100 years (27 mi)
- Jefferson County, MT: 4.03 m/s, 6,729 kWh, payback over 100 years (33 mi)
- Granite County, MT: 3.77 m/s, 5,477 kWh, payback over 100 years (50 mi)
- Madison County, MT: 4.63 m/s, 10,132 kWh, payback 70 years (53 mi)
- Beaverhead County, MT: 3.95 m/s, 6,329 kWh, payback over 100 years (54 mi)
- Broadwater County, MT: 3.97 m/s, 6,428 kWh, payback over 100 years (63 mi)
Sun versus wind in Silver Bow County
Silver Bow County gets 4.22 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,232 kWh a year; one kW of the turbine above makes 552. Kilowatt for kilowatt, panels make 2.2 times as much here as the turbine. 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.