Wind Turbine Payback in Yankton County, SD
Wind turbine payback in Yankton 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 Yankton County, SD averages 6.47 m/s (14.5 mph). A 10 kW turbine there would make about 23,186 kWh a year, worth $3,380 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 Yankton County
A home turbine is not worth buying for savings in Yankton County unless your spot is far windier than the county average, 8.1 m/s at the hub against 6.47 m/s here. Per kW, solar panels would make about 1,215 kWh a year here against the turbine's 2,319, 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 6.47. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of SD
Yankton County is the 234th 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 Yankton County
April is the strongest month here, at 7.18 m/s and about 2,328 kWh. August is the weakest, 5.50 m/s and 1,365 kWh, so the best month makes 1.7 times the worst. November to March brings in 44% of the year's output in Yankton County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.66 m/s | 2,088 kWh | $304 |
| February | 6.61 m/s | 1,856 kWh | $271 |
| March | 6.88 m/s | 2,226 kWh | $325 |
| April | 7.18 m/s | 2,328 kWh | $339 |
| May | 6.71 m/s | 2,122 kWh | $309 |
| June | 6.10 m/s | 1,678 kWh | $245 |
| July | 5.50 m/s | 1,365 kWh | $199 |
| August | 5.50 m/s | 1,365 kWh | $199 |
| September | 6.55 m/s | 1,956 kWh | $285 |
| October | 6.81 m/s | 2,182 kWh | $318 |
| November | 6.71 m/s | 2,048 kWh | $299 |
| December | 6.50 m/s | 1,988 kWh | $290 |
What a taller tower would buy
Measured at 10 m the wind in Yankton County averages 5.12 m/s; at 50 m it is 7.22 m/s. That gives a shear exponent of 0.214, typical of ordinary open country. Going from 20 m to 50 m takes output from 19,219 to 28,601 kWh a year, 49% 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 | 5.93 m/s | 19,219 kWh | 36 years |
| 30 m | 6.47 m/s | 23,203 kWh | 30 years |
| 40 m | 6.88 m/s | 26,205 kWh | 26 years |
| 50 m | 7.22 m/s | 28,601 kWh | 24 years |
Counties around Yankton County
2 of the 6 closest counties are windier at turbine height; the windiest, Cedar County, averages 6.66 m/s.
- Clay County, SD: 6.4 m/s, 22,669 kWh, payback 30 years (22 mi)
- Turner County, SD: 6.46 m/s, 23,112 kWh, payback 30 years (24 mi)
- Bon Homme County, SD: 6.45 m/s, 23,038 kWh, payback 30 years (25 mi)
- Cedar County, NE: 6.66 m/s, 24,582 kWh, payback 32 years (29 mi)
- Hutchinson County, SD: 6.45 m/s, 23,038 kWh, payback 30 years (29 mi)
- Knox County, NE: 6.62 m/s, 24,289 kWh, payback 32 years (36 mi)
Sun versus wind in Yankton County
Yankton County gets 4.16 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,215 kWh a year; one kW of the turbine above makes 2,319. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.9 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.