Wind Turbine Payback in Campbell County, SD
Wind turbine payback in Campbell 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 Campbell County, SD averages 6.57 m/s (14.7 mph). A 10 kW turbine there would make about 23,922 kWh a year, worth $3,488 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 Campbell County
A home turbine is not worth buying for savings in Campbell County unless your spot is far windier than the county average, 8.1 m/s at the hub against 6.57 m/s here. Per kW, solar panels would make about 1,206 kWh a year here against the turbine's 2,392, so get a solar quote first.
What would have to change
- Power would have to cost 21¢/kWh, 1.4 times what SD pays now.
- Or the average wind at the hub would have to be 8.1 m/s instead of 6.57. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of SD
Campbell County is the 130th 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 Campbell County
October is the strongest month here, at 7.09 m/s and about 2,354 kWh. July is the weakest, 5.82 m/s and 1,563 kWh, so the best month makes 1.5 times the worst. November to March brings in 42% of the year's output in Campbell County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.60 m/s | 2,050 kWh | $299 |
| February | 6.36 m/s | 1,719 kWh | $251 |
| March | 6.81 m/s | 2,178 kWh | $318 |
| April | 7.07 m/s | 2,262 kWh | $330 |
| May | 6.88 m/s | 2,223 kWh | $324 |
| June | 6.31 m/s | 1,809 kWh | $264 |
| July | 5.82 m/s | 1,563 kWh | $228 |
| August | 5.91 m/s | 1,619 kWh | $236 |
| September | 6.69 m/s | 2,038 kWh | $297 |
| October | 7.09 m/s | 2,354 kWh | $343 |
| November | 6.73 m/s | 2,060 kWh | $300 |
| December | 6.54 m/s | 2,010 kWh | $293 |
What a taller tower would buy
Measured at 10 m the wind in Campbell County averages 5.26 m/s; at 50 m it is 7.29 m/s. That gives a shear exponent of 0.203, typical of ordinary open country. Going from 20 m to 50 m takes output from 20,094 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 | 6.05 m/s | 20,094 kWh | 34 years |
| 30 m | 6.57 m/s | 23,936 kWh | 29 years |
| 40 m | 6.97 m/s | 26,808 kWh | 26 years |
| 50 m | 7.29 m/s | 29,090 kWh | 24 years |
Counties around Campbell County
2 of the 6 closest counties are windier at turbine height; the windiest, McIntosh County, averages 6.65 m/s.
- Walworth County, SD: 6.51 m/s, 23,481 kWh, payback 29 years (25 mi)
- McIntosh County, ND: 6.65 m/s, 24,509 kWh, payback 33 years (36 mi)
- Emmons County, ND: 6.53 m/s, 23,628 kWh, payback 34 years (36 mi)
- McPherson County, SD: 6.65 m/s, 24,509 kWh, payback 28 years (38 mi)
- Edmunds County, SD: 6.46 m/s, 23,112 kWh, payback 30 years (46 mi)
- Potter County, SD: 6.43 m/s, 22,891 kWh, payback 30 years (51 mi)
Sun versus wind in Campbell County
Campbell 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 2,392. 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.