Wind Turbine Payback in Perkins County, SD
Wind turbine payback in Perkins 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 Perkins County, SD averages 6.58 m/s (14.7 mph). A 10 kW turbine there would make about 23,996 kWh a year, worth $3,499 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 Perkins County
A home turbine is not worth buying for savings in Perkins County unless your spot is far windier than the county average, 8.1 m/s at the hub against 6.58 m/s here. Per kW, solar panels would make about 1,229 kWh a year here against the turbine's 2,400, 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 6.58. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of SD
Perkins County is the 126th 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 Perkins County
January is the strongest month here, at 7.17 m/s and about 2,399 kWh. July is the weakest, 5.69 m/s and 1,477 kWh, so the best month makes 1.6 times the worst. November to March brings in 46% of the year's output in Perkins County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 7.17 m/s | 2,399 kWh | $350 |
| February | 6.60 m/s | 1,854 kWh | $270 |
| March | 6.84 m/s | 2,197 kWh | $320 |
| April | 6.81 m/s | 2,110 kWh | $308 |
| May | 6.59 m/s | 2,041 kWh | $298 |
| June | 6.09 m/s | 1,675 kWh | $244 |
| July | 5.69 m/s | 1,477 kWh | $215 |
| August | 5.80 m/s | 1,550 kWh | $226 |
| September | 6.38 m/s | 1,850 kWh | $270 |
| October | 7.04 m/s | 2,318 kWh | $338 |
| November | 6.90 m/s | 2,164 kWh | $316 |
| December | 6.98 m/s | 2,285 kWh | $333 |
What a taller tower would buy
Measured at 10 m the wind in Perkins County averages 5.24 m/s; at 50 m it is 7.31 m/s. That gives a shear exponent of 0.207, typical of ordinary open country. Going from 20 m to 50 m takes output from 20,053 to 29,229 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 | 6.05 m/s | 20,053 kWh | 34 years |
| 30 m | 6.58 m/s | 23,970 kWh | 29 years |
| 40 m | 6.98 m/s | 26,900 kWh | 26 years |
| 50 m | 7.31 m/s | 29,229 kWh | 24 years |
Counties around Perkins County
2 of the 6 closest counties are windier at turbine height; the windiest, Adams County, averages 6.73 m/s.
- Adams County, ND: 6.73 m/s, 25,093 kWh, payback 32 years (43 mi)
- Harding County, SD: 6.62 m/s, 24,289 kWh, payback 28 years (49 mi)
- Ziebach County, SD: 6.41 m/s, 22,743 kWh, payback 30 years (52 mi)
- Meade County, SD: 6.32 m/s, 22,077 kWh, payback 31 years (62 mi)
- Corson County, SD: 6.52 m/s, 23,554 kWh, payback 29 years (64 mi)
- Butte County, SD: 6.15 m/s, 20,816 kWh, payback 33 years (65 mi)
Sun versus wind in Perkins County
Perkins County gets 4.21 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,229 kWh a year; one kW of the turbine above makes 2,400. 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.