Wind Turbine Payback in Clay County, MN
Wind turbine payback in Clay 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 Clay County, MN averages 6.45 m/s (14.4 mph). A 10 kW turbine there would make about 23,038 kWh a year, worth $3,787 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 Clay County
A home turbine is not worth buying for savings in Clay County unless your spot is far windier than the county average, 7.5 m/s at the hub against 6.45 m/s here. Per kW, solar panels would make about 1,142 kWh a year here against the turbine's 2,304, so get a solar quote first.
What would have to change
- Power would have to cost 22¢/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 6.45. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of MN
Clay County is the 257th 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 Clay County
April is the strongest month here, at 7.05 m/s and about 2,251 kWh. July is the weakest, 5.62 m/s and 1,434 kWh, so the best month makes 1.6 times the worst. November to March brings in 42% of the year's output in Clay County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.44 m/s | 1,948 kWh | $320 |
| February | 6.44 m/s | 1,764 kWh | $290 |
| March | 6.71 m/s | 2,116 kWh | $348 |
| April | 7.05 m/s | 2,251 kWh | $370 |
| May | 6.81 m/s | 2,183 kWh | $359 |
| June | 6.19 m/s | 1,737 kWh | $286 |
| July | 5.62 m/s | 1,434 kWh | $236 |
| August | 5.72 m/s | 1,501 kWh | $247 |
| September | 6.58 m/s | 1,972 kWh | $324 |
| October | 6.88 m/s | 2,222 kWh | $365 |
| November | 6.63 m/s | 2,005 kWh | $330 |
| December | 6.33 m/s | 1,880 kWh | $309 |
What a taller tower would buy
Measured at 10 m the wind in Clay County averages 5.14 m/s; at 50 m it is 7.16 m/s. That gives a shear exponent of 0.206, typical of ordinary open country. Going from 20 m to 50 m takes output from 19,174 to 28,179 kWh a year, 47% 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 | 5.93 m/s | 19,174 kWh | 32 years |
| 30 m | 6.44 m/s | 23,000 kWh | 26 years |
| 40 m | 6.84 m/s | 25,880 kWh | 24 years |
| 50 m | 7.16 m/s | 28,179 kWh | 22 years |
Counties around Clay County
2 of the 6 closest counties are windier at turbine height; the windiest, Becker County, averages 6.62 m/s.
- Norman County, MN: 6.37 m/s, 22,447 kWh, payback 27 years (30 mi)
- Becker County, MN: 6.62 m/s, 24,289 kWh, payback 25 years (36 mi)
- Cass County, ND: 6.35 m/s, 22,299 kWh, payback 36 years (36 mi)
- Wilkin County, MN: 6.45 m/s, 23,038 kWh, payback 26 years (37 mi)
- Mahnomen County, MN: 6.56 m/s, 23,849 kWh, payback 26 years (44 mi)
- Richland County, ND: 6.27 m/s, 21,706 kWh, payback 37 years (49 mi)
Sun versus wind in Clay County
Clay 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 2,304. 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.