Wind Turbine Payback in Corson County, SD
Wind turbine payback in Corson 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 Corson County, SD averages 6.52 m/s (14.6 mph). A 10 kW turbine there would make about 23,554 kWh a year, worth $3,434 at SD's 14.58¢/kWh. Against an installed cost of about $100,000, that is a payback of 29 years, and the turbine is built to last about 20.
What to do in Corson County
A home turbine is not worth buying for savings in Corson County unless your spot is far windier than the county average, 8.1 m/s at the hub against 6.52 m/s here. Per kW, solar panels would make about 1,206 kWh a year here against the turbine's 2,355, so get a solar quote first.
What would have to change
- Power would have to cost 21¢/kWh, 1.5 times what SD pays now.
- Or the average wind at the hub would have to be 8.1 m/s instead of 6.52. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of SD
Corson County is the 180th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in SD is Todd County at 6.77 m/s, payback 27 years.
Month by month in Corson County
October is the strongest month here, at 7.01 m/s and about 2,304 kWh. July is the weakest, 5.74 m/s and 1,512 kWh, so the best month makes 1.5 times the worst. November to March brings in 43% of the year's output in Corson County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.82 m/s | 2,189 kWh | $319 |
| February | 6.37 m/s | 1,724 kWh | $251 |
| March | 6.75 m/s | 2,144 kWh | $313 |
| April | 6.92 m/s | 2,177 kWh | $317 |
| May | 6.68 m/s | 2,100 kWh | $306 |
| June | 6.16 m/s | 1,715 kWh | $250 |
| July | 5.74 m/s | 1,512 kWh | $220 |
| August | 5.82 m/s | 1,563 kWh | $228 |
| September | 6.53 m/s | 1,945 kWh | $284 |
| October | 7.01 m/s | 2,304 kWh | $336 |
| November | 6.71 m/s | 2,053 kWh | $299 |
| December | 6.70 m/s | 2,111 kWh | $308 |
What a taller tower would buy
Measured at 10 m the wind in Corson County averages 5.2 m/s; at 50 m it is 7.24 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 19,664 to 28,741 kWh a year, 46% 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 | 5.99 m/s | 19,664 kWh | 35 years |
| 30 m | 6.52 m/s | 23,531 kWh | 29 years |
| 40 m | 6.91 m/s | 26,431 kWh | 26 years |
| 50 m | 7.24 m/s | 28,741 kWh | 24 years |
Counties around Corson County
3 of the 6 closest counties are windier at turbine height; the windiest, Grant County, averages 6.67 m/s.
- Sioux County, ND: 6.56 m/s, 23,849 kWh, payback 34 years (30 mi)
- Dewey County, SD: 6.39 m/s, 22,595 kWh, payback 30 years (41 mi)
- Grant County, ND: 6.67 m/s, 24,655 kWh, payback 33 years (51 mi)
- Ziebach County, SD: 6.41 m/s, 22,743 kWh, payback 30 years (53 mi)
- Campbell County, SD: 6.57 m/s, 23,922 kWh, payback 29 years (57 mi)
- Walworth County, SD: 6.51 m/s, 23,481 kWh, payback 29 years (59 mi)
Sun versus wind in Corson County
Corson County gets 4.13 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,206 kWh a year; one kW of the turbine above makes 2,355. 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.