Wind Turbine Payback in Ziebach County, SD
Wind turbine payback in Ziebach 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 Ziebach County, SD averages 6.41 m/s (14.3 mph). A 10 kW turbine there would make about 22,743 kWh a year, worth $3,316 at SD's 14.58¢/kWh. Against an installed cost of about $100,000, that is a payback of 30 years, and the turbine is built to last about 20.
What to do in Ziebach County
A home turbine is not worth buying for savings in Ziebach County unless your spot is far windier than the county average, 8.1 m/s at the hub against 6.41 m/s here. Per kW, solar panels would make about 1,244 kWh a year here against the turbine's 2,274, so get a solar quote first.
What would have to change
- Power would have to cost 22¢/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 6.41. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of SD
Ziebach County is the 309th 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 Ziebach County
October is the strongest month here, at 6.87 m/s and about 2,219 kWh. July is the weakest, 5.61 m/s and 1,432 kWh, so the best month makes 1.5 times the worst. November to March brings in 44% of the year's output in Ziebach County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.84 m/s | 2,202 kWh | $321 |
| February | 6.35 m/s | 1,711 kWh | $249 |
| March | 6.69 m/s | 2,108 kWh | $307 |
| April | 6.76 m/s | 2,083 kWh | $304 |
| May | 6.51 m/s | 1,996 kWh | $291 |
| June | 5.96 m/s | 1,598 kWh | $233 |
| July | 5.61 m/s | 1,432 kWh | $209 |
| August | 5.69 m/s | 1,477 kWh | $215 |
| September | 6.32 m/s | 1,817 kWh | $265 |
| October | 6.87 m/s | 2,219 kWh | $324 |
| November | 6.64 m/s | 2,007 kWh | $293 |
| December | 6.67 m/s | 2,091 kWh | $305 |
What a taller tower would buy
Measured at 10 m the wind in Ziebach County averages 5.09 m/s; at 50 m it is 7.14 m/s. That gives a shear exponent of 0.210, typical of ordinary open country. Going from 20 m to 50 m takes output from 18,892 to 28,038 kWh a year, 48% 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 | 5.89 m/s | 18,892 kWh | 36 years |
| 30 m | 6.41 m/s | 22,770 kWh | 30 years |
| 40 m | 6.81 m/s | 25,697 kWh | 27 years |
| 50 m | 7.14 m/s | 28,038 kWh | 25 years |
Counties around Ziebach County
2 of the 6 closest counties are windier at turbine height; the windiest, Perkins County, averages 6.58 m/s.
- Dewey County, SD: 6.39 m/s, 22,595 kWh, payback 30 years (42 mi)
- Haakon County, SD: 6.3 m/s, 21,929 kWh, payback 31 years (49 mi)
- Perkins County, SD: 6.58 m/s, 23,996 kWh, payback 29 years (52 mi)
- Corson County, SD: 6.52 m/s, 23,554 kWh, payback 29 years (53 mi)
- Meade County, SD: 6.32 m/s, 22,077 kWh, payback 31 years (58 mi)
- Stanley County, SD: 6.31 m/s, 22,003 kWh, payback 31 years (60 mi)
Sun versus wind in Ziebach County
Ziebach County gets 4.26 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,244 kWh a year; one kW of the turbine above makes 2,274. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.8 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.