Wind Turbine Payback in Toole County, MT
Wind turbine payback in Toole 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 Toole County, MT averages 6.17 m/s (13.8 mph). A 10 kW turbine there would make about 20,965 kWh a year, worth $2,962 at MT's 14.13¢/kWh. Against an installed cost of about $100,000, that is a payback of 34 years, and the turbine is built to last about 20.
What to do in Toole County
A home turbine is not worth buying for savings in Toole County unless your spot is far windier than the county average, 8.2 m/s at the hub against 6.17 m/s here. Per kW, solar panels would make about 1,142 kWh a year here against the turbine's 2,097, so get a solar quote first.
What would have to change
- Power would have to cost 24¢/kWh, 1.7 times what MT pays now.
- Or the average wind at the hub would have to be 8.2 m/s instead of 6.17. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of MT
Toole County is the 608th 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 Toole County
January is the strongest month here, at 7.23 m/s and about 2,435 kWh. August is the weakest, 4.97 m/s and 1,045 kWh, so the best month makes 2.3 times the worst. November to March brings in 51% of the year's output in Toole County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 7.23 m/s | 2,435 kWh | $344 |
| February | 6.52 m/s | 1,807 kWh | $255 |
| March | 6.56 m/s | 2,028 kWh | $287 |
| April | 6.23 m/s | 1,758 kWh | $248 |
| May | 5.81 m/s | 1,554 kWh | $220 |
| June | 5.66 m/s | 1,412 kWh | $200 |
| July | 5.22 m/s | 1,195 kWh | $169 |
| August | 4.97 m/s | 1,045 kWh | $148 |
| September | 5.44 m/s | 1,280 kWh | $181 |
| October | 6.48 m/s | 1,973 kWh | $279 |
| November | 7.01 m/s | 2,228 kWh | $315 |
| December | 6.87 m/s | 2,215 kWh | $313 |
What a taller tower would buy
Measured at 10 m the wind in Toole County averages 4.78 m/s; at 50 m it is 6.94 m/s. That gives a shear exponent of 0.232, typical of ordinary open country. Going from 20 m to 50 m takes output from 16,841 to 26,613 kWh a year, 58% 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 | 5.61 m/s | 16,841 kWh | 42 years |
| 30 m | 6.16 m/s | 20,923 kWh | 34 years |
| 40 m | 6.59 m/s | 24,068 kWh | 29 years |
| 50 m | 6.94 m/s | 26,613 kWh | 27 years |
Counties around Toole County
2 of the 6 closest counties are windier at turbine height; the windiest, Liberty County, averages 6.21 m/s.
- Liberty County, MT: 6.21 m/s, 21,262 kWh, payback 33 years (32 mi)
- Pondera County, MT: 5.4 m/s, 15,319 kWh, payback 46 years (36 mi)
- Glacier County, MT: 5.52 m/s, 16,181 kWh, payback 44 years (58 mi)
- Teton County, MT: 5.4 m/s, 15,319 kWh, payback 46 years (62 mi)
- Hill County, MT: 6.21 m/s, 21,262 kWh, payback 33 years (74 mi)
- Chouteau County, MT: 6.09 m/s, 20,371 kWh, payback 35 years (79 mi)
Sun versus wind in Toole County
Toole County gets 3.91 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,142 kWh a year; one kW of the turbine above makes 2,097. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.8 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.