Wind Turbine Payback in McPherson County, SD
Wind turbine payback in McPherson 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 McPherson County, SD averages 6.65 m/s (14.9 mph). A 10 kW turbine there would make about 24,509 kWh a year, worth $3,573 at SD's 14.58¢/kWh. Against an installed cost of about $100,000, that is a payback of 28 years, and the turbine is built to last about 20.
What to do in McPherson County
A home turbine is not worth buying for savings in McPherson County unless your spot is far windier than the county average, 8.1 m/s at the hub against 6.65 m/s here. Per kW, solar panels would make about 1,197 kWh a year here against the turbine's 2,451, so get a solar quote first.
What would have to change
- Power would have to cost 20¢/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 6.65. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of SD
McPherson County is the 92nd 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 McPherson County
October is the strongest month here, at 7.20 m/s and about 2,415 kWh. July is the weakest, 5.76 m/s and 1,525 kWh, so the best month makes 1.6 times the worst. November to March brings in 43% of the year's output in McPherson County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.82 m/s | 2,185 kWh | $319 |
| February | 6.57 m/s | 1,832 kWh | $267 |
| March | 6.84 m/s | 2,202 kWh | $321 |
| April | 7.11 m/s | 2,284 kWh | $333 |
| May | 6.93 m/s | 2,257 kWh | $329 |
| June | 6.30 m/s | 1,799 kWh | $262 |
| July | 5.76 m/s | 1,525 kWh | $222 |
| August | 5.86 m/s | 1,587 kWh | $231 |
| September | 6.73 m/s | 2,061 kWh | $300 |
| October | 7.20 m/s | 2,415 kWh | $352 |
| November | 6.91 m/s | 2,168 kWh | $316 |
| December | 6.75 m/s | 2,146 kWh | $313 |
What a taller tower would buy
Measured at 10 m the wind in McPherson County averages 5.31 m/s; at 50 m it is 7.38 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 20,565 to 29,714 kWh a year, 44% 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 | 6.12 m/s | 20,565 kWh | 33 years |
| 30 m | 6.65 m/s | 24,481 kWh | 28 years |
| 40 m | 7.05 m/s | 27,400 kWh | 25 years |
| 50 m | 7.38 m/s | 29,714 kWh | 23 years |
Counties around McPherson County
None of the 6 closest counties is windier than McPherson County.
- McIntosh County, ND: 6.65 m/s, 24,509 kWh, payback 33 years (24 mi)
- Edmunds County, SD: 6.46 m/s, 23,112 kWh, payback 30 years (26 mi)
- Campbell County, SD: 6.57 m/s, 23,922 kWh, payback 29 years (38 mi)
- Dickey County, ND: 6.5 m/s, 23,407 kWh, payback 34 years (41 mi)
- Brown County, SD: 6.3 m/s, 21,929 kWh, payback 31 years (44 mi)
- Walworth County, SD: 6.51 m/s, 23,481 kWh, payback 29 years (47 mi)
Sun versus wind in McPherson County
McPherson County gets 4.1 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,197 kWh a year; one kW of the turbine above makes 2,451. 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.