Wind Turbine Payback in Mahnomen County, MN
Wind turbine payback in Mahnomen 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 Mahnomen County, MN averages 6.56 m/s (14.7 mph). A 10 kW turbine there would make about 23,849 kWh a year, worth $3,921 at MN's 16.44¢/kWh. Against an installed cost of about $100,000, that is a payback of 26 years, and the turbine is built to last about 20.
What to do in Mahnomen County
A home turbine is not worth buying for savings in Mahnomen County unless your spot is far windier than the county average, 7.5 m/s at the hub against 6.56 m/s here. Per kW, solar panels would make about 1,083 kWh a year here against the turbine's 2,385, so get a solar quote first.
What would have to change
- Power would have to cost 21¢/kWh, 1.3 times what MN pays now.
- Or the average wind at the hub would have to be 7.5 m/s instead of 6.56. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of MN
Mahnomen County is the 139th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in MN is Lincoln County at 6.68 m/s, payback 25 years.
Month by month in Mahnomen County
October is the strongest month here, at 6.93 m/s and about 2,254 kWh. July is the weakest, 5.77 m/s and 1,527 kWh, so the best month makes 1.5 times the worst. November to March brings in 43% of the year's output in Mahnomen County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.71 m/s | 2,120 kWh | $349 |
| February | 6.68 m/s | 1,895 kWh | $312 |
| March | 6.76 m/s | 2,148 kWh | $353 |
| April | 7.00 m/s | 2,223 kWh | $365 |
| May | 6.74 m/s | 2,137 kWh | $351 |
| June | 6.27 m/s | 1,785 kWh | $293 |
| July | 5.77 m/s | 1,527 kWh | $251 |
| August | 5.88 m/s | 1,600 kWh | $263 |
| September | 6.69 m/s | 2,036 kWh | $335 |
| October | 6.93 m/s | 2,254 kWh | $371 |
| November | 6.79 m/s | 2,101 kWh | $345 |
| December | 6.50 m/s | 1,986 kWh | $326 |
What a taller tower would buy
Measured at 10 m the wind in Mahnomen County averages 5.24 m/s; at 50 m it is 7.28 m/s. That gives a shear exponent of 0.204, typical of ordinary open country. Going from 20 m to 50 m takes output from 19,992 to 29,020 kWh a year, 45% 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 | 6.04 m/s | 19,992 kWh | 30 years |
| 30 m | 6.56 m/s | 23,845 kWh | 26 years |
| 40 m | 6.96 m/s | 26,728 kWh | 23 years |
| 50 m | 7.28 m/s | 29,020 kWh | 21 years |
Counties around Mahnomen County
1 of the 6 closest counties is windier at turbine height; the windiest, Becker County, averages 6.62 m/s.
- Clearwater County, MN: 6.56 m/s, 23,849 kWh, payback 26 years (27 mi)
- Becker County, MN: 6.62 m/s, 24,289 kWh, payback 25 years (27 mi)
- Norman County, MN: 6.37 m/s, 22,447 kWh, payback 27 years (31 mi)
- Red Lake County, MN: 6.34 m/s, 22,225 kWh, payback 27 years (39 mi)
- Polk County, MN: 6.34 m/s, 22,225 kWh, payback 27 years (41 mi)
- Clay County, MN: 6.45 m/s, 23,038 kWh, payback 26 years (44 mi)
Sun versus wind in Mahnomen County
Mahnomen County gets 3.71 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,083 kWh a year; one kW of the turbine above makes 2,385. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 2.2 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.