Wind Turbine Payback in Mille Lacs County, MN
Wind turbine payback in Mille Lacs 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 Mille Lacs County, MN averages 6.32 m/s (14.1 mph). A 10 kW turbine there would make about 22,077 kWh a year, worth $3,629 at MN's 16.44¢/kWh. Against an installed cost of about $100,000, that is a payback of 28 years, and the turbine is built to last about 20.
What to do in Mille Lacs County
A home turbine is not worth buying for savings in Mille Lacs County unless your spot is far windier than the county average, 7.5 m/s at the hub against 6.32 m/s here. Per kW, solar panels would make about 1,110 kWh a year here against the turbine's 2,208, so get a solar quote first.
What would have to change
- Power would have to cost 23¢/kWh, 1.4 times what MN pays now.
- Or the average wind at the hub would have to be 7.5 m/s instead of 6.32. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of MN
Mille Lacs County is the 452nd 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 Mille Lacs County
April is the strongest month here, at 6.93 m/s and about 2,182 kWh. July is the weakest, 5.38 m/s and 1,288 kWh, so the best month makes 1.7 times the worst. November to March brings in 44% of the year's output in Mille Lacs County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.60 m/s | 2,050 kWh | $337 |
| February | 6.68 m/s | 1,897 kWh | $312 |
| March | 6.57 m/s | 2,033 kWh | $334 |
| April | 6.93 m/s | 2,182 kWh | $359 |
| May | 6.49 m/s | 1,983 kWh | $326 |
| June | 5.94 m/s | 1,585 kWh | $261 |
| July | 5.38 m/s | 1,288 kWh | $212 |
| August | 5.49 m/s | 1,353 kWh | $222 |
| September | 6.37 m/s | 1,842 kWh | $303 |
| October | 6.70 m/s | 2,111 kWh | $347 |
| November | 6.51 m/s | 1,929 kWh | $317 |
| December | 6.27 m/s | 1,842 kWh | $303 |
What a taller tower would buy
Measured at 10 m the wind in Mille Lacs County averages 5.01 m/s; at 50 m it is 7.04 m/s. That gives a shear exponent of 0.211, typical of ordinary open country. Going from 20 m to 50 m takes output from 18,244 to 27,328 kWh a year, 50% 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 | 5.8 m/s | 18,244 kWh | 33 years |
| 30 m | 6.32 m/s | 22,082 kWh | 28 years |
| 40 m | 6.72 m/s | 24,993 kWh | 24 years |
| 50 m | 7.04 m/s | 27,328 kWh | 22 years |
Counties around Mille Lacs County
1 of the 6 closest counties is windier at turbine height; the windiest, Morrison County, averages 6.34 m/s.
- Kanabec County, MN: 6.14 m/s, 20,742 kWh, payback 29 years (16 mi)
- Benton County, MN: 6.13 m/s, 20,668 kWh, payback 29 years (24 mi)
- Isanti County, MN: 5.96 m/s, 19,408 kWh, payback 31 years (30 mi)
- Morrison County, MN: 6.34 m/s, 22,225 kWh, payback 27 years (31 mi)
- Sherburne County, MN: 6.13 m/s, 20,668 kWh, payback 29 years (34 mi)
- Pine County, MN: 5.77 m/s, 18,006 kWh, payback 34 years (43 mi)
Sun versus wind in Mille Lacs County
Mille Lacs County gets 3.8 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,110 kWh a year; one kW of the turbine above makes 2,208. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 2.0 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.