Wind Turbine Payback in Jefferson County, MT
Wind turbine payback in Jefferson 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 Jefferson County, MT averages 4.03 m/s (9 mph). A 10 kW turbine there would make about 6,729 kWh a year, worth $951 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 Jefferson County
A home turbine is not worth buying for savings in Jefferson County unless your spot is far windier than the county average, 8.2 m/s at the hub against 4.03 m/s here. Per kW, solar panels would make about 1,171 kWh a year here against the turbine's 673, so get a solar quote first.
What would have to change
- Power would have to cost 74¢/kWh, 5.3 times what MT pays now.
- Or the average wind at the hub would have to be 8.2 m/s instead of 4.03. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of MT
Jefferson County is the 2,037th 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 Jefferson County
January is the strongest month here, at 4.96 m/s and about 1,043 kWh. July is the weakest, 3.11 m/s and 250 kWh, so the best month makes 4.2 times the worst. November to March brings in 61% of the year's output in Jefferson County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 4.96 m/s | 1,043 kWh | $147 |
| February | 4.54 m/s | 737 kWh | $104 |
| March | 4.51 m/s | 798 kWh | $113 |
| April | 4.05 m/s | 561 kWh | $79 |
| May | 3.56 m/s | 389 kWh | $55 |
| June | 3.41 m/s | 329 kWh | $46 |
| July | 3.11 m/s | 250 kWh | $35 |
| August | 3.14 m/s | 257 kWh | $36 |
| September | 3.51 m/s | 359 kWh | $51 |
| October | 4.16 m/s | 630 kWh | $89 |
| November | 4.69 m/s | 865 kWh | $122 |
| December | 4.77 m/s | 936 kWh | $132 |
What a taller tower would buy
Measured at 10 m the wind in Jefferson County averages 2.98 m/s; at 50 m it is 4.64 m/s. That gives a shear exponent of 0.275, typical of ordinary open country. Going from 20 m to 50 m takes output from 4,763 to 10,195 kWh a year, 114% 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 | 3.61 m/s | 4,763 kWh | over 100 years |
| 30 m | 4.03 m/s | 6,739 kWh | over 100 years |
| 40 m | 4.36 m/s | 8,539 kWh | 83 years |
| 50 m | 4.64 m/s | 10,195 kWh | 69 years |
Counties around Jefferson County
3 of the 6 closest counties are windier at turbine height; the windiest, Madison County, averages 4.63 m/s.
- Broadwater County, MT: 3.97 m/s, 6,428 kWh, payback over 100 years (30 mi)
- Silver Bow County, MT: 3.78 m/s, 5,523 kWh, payback over 100 years (33 mi)
- Deer Lodge County, MT: 3.65 m/s, 4,948 kWh, payback over 100 years (52 mi)
- Madison County, MT: 4.63 m/s, 10,132 kWh, payback 70 years (56 mi)
- Gallatin County, MT: 4.18 m/s, 7,515 kWh, payback 94 years (60 mi)
- Meagher County, MT: 4.63 m/s, 10,132 kWh, payback 70 years (63 mi)
Sun versus wind in Jefferson County
Jefferson County gets 4.01 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,171 kWh a year; one kW of the turbine above makes 673. Kilowatt for kilowatt, panels make 1.7 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.