Wind Turbine Payback in Blue Earth County, MN
Wind turbine payback in Blue Earth 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 Blue Earth County, MN averages 6.38 m/s (14.3 mph). A 10 kW turbine there would make about 22,521 kWh a year, worth $3,702 at MN's 16.44¢/kWh. Against an installed cost of about $100,000, that is a payback of 27 years, and the turbine is built to last about 20.
What to do in Blue Earth County
A home turbine is not worth buying for savings in Blue Earth County unless your spot is far windier than the county average, 7.5 m/s at the hub against 6.38 m/s here. Per kW, solar panels would make about 1,145 kWh a year here against the turbine's 2,252, so get a solar quote first.
What would have to change
- Power would have to cost 22¢/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 6.38. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of MN
Blue Earth County is the 359th 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 Blue Earth County
April is the strongest month here, at 7.11 m/s and about 2,288 kWh. August is the weakest, 5.23 m/s and 1,198 kWh, so the best month makes 1.9 times the worst. November to March brings in 46% of the year's output in Blue Earth County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.72 m/s | 2,124 kWh | $349 |
| February | 6.72 m/s | 1,918 kWh | $315 |
| March | 6.81 m/s | 2,179 kWh | $358 |
| April | 7.11 m/s | 2,288 kWh | $376 |
| May | 6.56 m/s | 2,023 kWh | $333 |
| June | 5.94 m/s | 1,581 kWh | $260 |
| July | 5.26 m/s | 1,214 kWh | $200 |
| August | 5.23 m/s | 1,198 kWh | $197 |
| September | 6.30 m/s | 1,800 kWh | $296 |
| October | 6.71 m/s | 2,118 kWh | $348 |
| November | 6.77 m/s | 2,087 kWh | $343 |
| December | 6.55 m/s | 2,018 kWh | $332 |
What a taller tower would buy
Measured at 10 m the wind in Blue Earth County averages 5.05 m/s; at 50 m it is 7.12 m/s. That gives a shear exponent of 0.213, typical of ordinary open country. Going from 20 m to 50 m takes output from 18,651 to 27,897 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 | 5.86 m/s | 18,651 kWh | 33 years |
| 30 m | 6.39 m/s | 22,565 kWh | 27 years |
| 40 m | 6.79 m/s | 25,526 kWh | 24 years |
| 50 m | 7.12 m/s | 27,897 kWh | 22 years |
Counties around Blue Earth County
2 of the 6 closest counties are windier at turbine height; the windiest, Martin County, averages 6.5 m/s.
- Waseca County, MN: 6.38 m/s, 22,521 kWh, payback 27 years (24 mi)
- Nicollet County, MN: 6.27 m/s, 21,706 kWh, payback 28 years (24 mi)
- Faribault County, MN: 6.47 m/s, 23,186 kWh, payback 26 years (25 mi)
- Watonwan County, MN: 6.38 m/s, 22,521 kWh, payback 27 years (28 mi)
- Le Sueur County, MN: 6.23 m/s, 21,410 kWh, payback 28 years (29 mi)
- Martin County, MN: 6.5 m/s, 23,407 kWh, payback 26 years (34 mi)
Sun versus wind in Blue Earth County
Blue Earth County gets 3.92 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,145 kWh a year; one kW of the turbine above makes 2,252. 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.