Wind Turbine Payback in Lake County, MT
Wind turbine payback in Lake 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 Lake County, MT averages 2.95 m/s (6.6 mph). A 10 kW turbine there would make about 2,455 kWh a year, worth $347 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 Lake County
A home turbine is not worth buying for savings in Lake County unless your spot is far windier than the county average, 8.2 m/s at the hub against 2.95 m/s here. Per kW, solar panels would make about 1,092 kWh a year here against the turbine's 246, so get a solar quote first.
What would have to change
- Power would have to cost 204¢/kWh, 14.4 times what MT pays now.
- Or the average wind at the hub would have to be 8.2 m/s instead of 2.95. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of MT
Lake County is the 3,083rd 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 Lake County
March is the strongest month here, at 3.23 m/s and about 282 kWh. August is the weakest, 2.63 m/s and 138 kWh, so the best month makes 2.0 times the worst. November to March brings in 44% of the year's output in Lake County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 2.92 m/s | 201 kWh | $28 |
| February | 2.91 m/s | 180 kWh | $25 |
| March | 3.23 m/s | 282 kWh | $40 |
| April | 3.18 m/s | 261 kWh | $37 |
| May | 2.98 m/s | 216 kWh | $31 |
| June | 3.00 m/s | 213 kWh | $30 |
| July | 2.78 m/s | 169 kWh | $24 |
| August | 2.63 m/s | 138 kWh | $19 |
| September | 2.77 m/s | 162 kWh | $23 |
| October | 3.03 m/s | 229 kWh | $32 |
| November | 3.08 m/s | 233 kWh | $33 |
| December | 2.90 m/s | 197 kWh | $28 |
What a taller tower would buy
Measured at 10 m the wind in Lake County averages 2.24 m/s; at 50 m it is 3.36 m/s. That gives a shear exponent of 0.252, typical of ordinary open country. Going from 20 m to 50 m takes output from 1,719 to 3,794 kWh a year, 121% 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 | 2.67 m/s | 1,719 kWh | over 100 years |
| 30 m | 2.95 m/s | 2,467 kWh | over 100 years |
| 40 m | 3.18 m/s | 3,153 kWh | over 100 years |
| 50 m | 3.36 m/s | 3,794 kWh | over 100 years |
Counties around Lake County
4 of the 6 closest counties are windier at turbine height; the windiest, Teton County, averages 5.4 m/s.
- Missoula County, MT: 2.8 m/s, 2,047 kWh, payback over 100 years (43 mi)
- Flathead County, MT: 3.37 m/s, 3,830 kWh, payback over 100 years (45 mi)
- Sanders County, MT: 2.89 m/s, 2,287 kWh, payback over 100 years (52 mi)
- Mineral County, MT: 3 m/s, 2,601 kWh, payback over 100 years (59 mi)
- Powell County, MT: 3.35 m/s, 3,757 kWh, payback over 100 years (77 mi)
- Teton County, MT: 5.4 m/s, 15,319 kWh, payback 46 years (85 mi)
Sun versus wind in Lake County
Lake County gets 3.74 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,092 kWh a year; one kW of the turbine above makes 246. Kilowatt for kilowatt, panels make 4.4 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.