Wind Turbine Payback in Sioux County, ND
Wind turbine payback in Sioux 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 Sioux County, ND averages 6.56 m/s (14.7 mph). A 10 kW turbine there would make about 23,849 kWh a year, worth $2,972 at ND's 12.46¢/kWh. Against an installed cost of about $100,000, that is a payback of 34 years, and the turbine is built to last about 20.
What to do in Sioux County
A home turbine is not worth buying for savings in Sioux County unless your spot is far windier than the county average, 9.1 m/s at the hub against 6.56 m/s here. Per kW, solar panels would make about 1,177 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, 1.7 times what ND pays now.
- Or the average wind at the hub would have to be 9.1 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 ND
Sioux County is the 139th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in ND is Bowman County at 6.79 m/s, payback 31 years.
Month by month in Sioux County
October is the strongest month here, at 7.07 m/s and about 2,339 kWh. July is the weakest, 5.75 m/s and 1,514 kWh, so the best month makes 1.5 times the worst. November to March brings in 44% of the year's output in Sioux County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.89 m/s | 2,229 kWh | $278 |
| February | 6.43 m/s | 1,756 kWh | $219 |
| March | 6.80 m/s | 2,174 kWh | $271 |
| April | 6.94 m/s | 2,189 kWh | $273 |
| May | 6.70 m/s | 2,113 kWh | $263 |
| June | 6.20 m/s | 1,739 kWh | $217 |
| July | 5.75 m/s | 1,514 kWh | $189 |
| August | 5.86 m/s | 1,587 kWh | $198 |
| September | 6.57 m/s | 1,963 kWh | $245 |
| October | 7.07 m/s | 2,339 kWh | $291 |
| November | 6.82 m/s | 2,115 kWh | $264 |
| December | 6.76 m/s | 2,152 kWh | $268 |
What a taller tower would buy
Measured at 10 m the wind in Sioux County averages 5.24 m/s; at 50 m it is 7.29 m/s. That gives a shear exponent of 0.205, typical of ordinary open country. Going from 20 m to 50 m takes output from 20,012 to 29,090 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 | 20,012 kWh | 40 years |
| 30 m | 6.57 m/s | 23,887 kWh | 34 years |
| 40 m | 6.96 m/s | 26,785 kWh | 30 years |
| 50 m | 7.29 m/s | 29,090 kWh | 28 years |
Counties around Sioux County
2 of the 6 closest counties are windier at turbine height; the windiest, Grant County, averages 6.67 m/s.
- Corson County, SD: 6.52 m/s, 23,554 kWh, payback 29 years (30 mi)
- Grant County, ND: 6.67 m/s, 24,655 kWh, payback 33 years (32 mi)
- Emmons County, ND: 6.53 m/s, 23,628 kWh, payback 34 years (41 mi)
- Morton County, ND: 6.53 m/s, 23,628 kWh, payback 34 years (43 mi)
- Campbell County, SD: 6.57 m/s, 23,922 kWh, payback 29 years (56 mi)
- Burleigh County, ND: 6.43 m/s, 22,891 kWh, payback 35 years (66 mi)
Sun versus wind in Sioux County
Sioux County gets 4.03 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,177 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 2.0 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.