Wind Turbine Payback in Hill County, MT
Wind turbine payback in Hill 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 Hill County, MT averages 6.21 m/s (13.9 mph). A 10 kW turbine there would make about 21,262 kWh a year, worth $3,004 at MT's 14.13¢/kWh. Against an installed cost of about $100,000, that is a payback of 33 years, and the turbine is built to last about 20.
What to do in Hill County
A home turbine is not worth buying for savings in Hill County unless your spot is far windier than the county average, 8.2 m/s at the hub against 6.21 m/s here. Per kW, solar panels would make about 1,142 kWh a year here against the turbine's 2,126, 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 6.21. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of MT
Hill County is the 576th 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 Hill County
January is the strongest month here, at 7.05 m/s and about 2,329 kWh. August is the weakest, 5.10 m/s and 1,121 kWh, so the best month makes 2.1 times the worst. November to March brings in 49% of the year's output in Hill County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 7.05 m/s | 2,329 kWh | $329 |
| February | 6.30 m/s | 1,684 kWh | $238 |
| March | 6.56 m/s | 2,027 kWh | $286 |
| April | 6.31 m/s | 1,810 kWh | $256 |
| May | 5.99 m/s | 1,668 kWh | $236 |
| June | 5.78 m/s | 1,484 kWh | $210 |
| July | 5.38 m/s | 1,291 kWh | $182 |
| August | 5.10 m/s | 1,121 kWh | $158 |
| September | 5.62 m/s | 1,387 kWh | $196 |
| October | 6.55 m/s | 2,021 kWh | $286 |
| November | 7.08 m/s | 2,269 kWh | $321 |
| December | 6.85 m/s | 2,204 kWh | $311 |
What a taller tower would buy
Measured at 10 m the wind in Hill County averages 4.87 m/s; at 50 m it is 6.96 m/s. That gives a shear exponent of 0.222, typical of ordinary open country. Going from 20 m to 50 m takes output from 17,338 to 26,756 kWh a year, 54% 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 | 5.68 m/s | 17,338 kWh | 41 years |
| 30 m | 6.21 m/s | 21,290 kWh | 33 years |
| 40 m | 6.62 m/s | 24,316 kWh | 29 years |
| 50 m | 6.96 m/s | 26,756 kWh | 27 years |
Counties around Hill County
1 of the 6 closest counties is windier at turbine height; the windiest, Blaine County, averages 6.31 m/s.
- Liberty County, MT: 6.21 m/s, 21,262 kWh, payback 33 years (43 mi)
- Chouteau County, MT: 6.09 m/s, 20,371 kWh, payback 35 years (54 mi)
- Blaine County, MT: 6.31 m/s, 22,003 kWh, payback 32 years (54 mi)
- Toole County, MT: 6.17 m/s, 20,965 kWh, payback 34 years (74 mi)
- Pondera County, MT: 5.4 m/s, 15,319 kWh, payback 46 years (101 mi)
- Phillips County, MT: 6.17 m/s, 20,965 kWh, payback 34 years (103 mi)
Sun versus wind in Hill County
Hill 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 2,126. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.9 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.