Wind Turbine Payback in Oglala Lakota County, SD
Wind turbine payback in Oglala Lakota 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 Oglala Lakota County, SD averages 5.99 m/s (13.4 mph). A 10 kW turbine there would make about 19,630 kWh a year, worth $2,862 at SD's 14.58¢/kWh. Against an installed cost of about $100,000, that is a payback of 35 years, and the turbine is built to last about 20.
What to do in Oglala Lakota County
A home turbine is not worth buying for savings in Oglala Lakota County unless your spot is far windier than the county average, 8.1 m/s at the hub against 5.99 m/s here. Per kW, solar panels would make about 1,279 kWh a year here against the turbine's 1,963, so get a solar quote first.
What would have to change
- Power would have to cost 25¢/kWh, 1.7 times what SD pays now.
- Or the average wind at the hub would have to be 8.1 m/s instead of 5.99. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of SD
Oglala Lakota County is the 858th 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 Oglala Lakota County
April is the strongest month here, at 6.38 m/s and about 1,849 kWh. July is the weakest, 5.46 m/s and 1,337 kWh, so the best month makes 1.4 times the worst. November to March brings in 44% of the year's output in Oglala Lakota County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.25 m/s | 1,832 kWh | $267 |
| February | 6.02 m/s | 1,523 kWh | $222 |
| March | 6.22 m/s | 1,809 kWh | $264 |
| April | 6.38 m/s | 1,849 kWh | $270 |
| May | 6.03 m/s | 1,692 kWh | $247 |
| June | 5.66 m/s | 1,416 kWh | $206 |
| July | 5.46 m/s | 1,337 kWh | $195 |
| August | 5.53 m/s | 1,381 kWh | $201 |
| September | 5.89 m/s | 1,550 kWh | $226 |
| October | 6.14 m/s | 1,765 kWh | $257 |
| November | 6.22 m/s | 1,756 kWh | $256 |
| December | 6.17 m/s | 1,781 kWh | $260 |
What a taller tower would buy
Measured at 10 m the wind in Oglala Lakota County averages 4.67 m/s; at 50 m it is 6.73 m/s. That gives a shear exponent of 0.227, typical of ordinary open country. Going from 20 m to 50 m takes output from 15,793 to 25,093 kWh a year, 59% 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 | 5.47 m/s | 15,793 kWh | 43 years |
| 30 m | 5.99 m/s | 19,653 kWh | 35 years |
| 40 m | 6.4 m/s | 22,651 kWh | 30 years |
| 50 m | 6.73 m/s | 25,093 kWh | 27 years |
Counties around Oglala Lakota County
4 of the 6 closest counties are windier at turbine height; the windiest, Bennett County, averages 6.73 m/s.
- Bennett County, SD: 6.73 m/s, 25,093 kWh, payback 27 years (46 mi)
- Pennington County, SD: 5.76 m/s, 17,932 kWh, payback 38 years (48 mi)
- Fall River County, SD: 6.21 m/s, 21,262 kWh, payback 32 years (48 mi)
- Custer County, SD: 5.58 m/s, 16,616 kWh, payback 41 years (51 mi)
- Dawes County, NE: 6.59 m/s, 24,069 kWh, payback 32 years (52 mi)
- Jackson County, SD: 6.49 m/s, 23,333 kWh, payback 29 years (53 mi)
Sun versus wind in Oglala Lakota County
Oglala Lakota County gets 4.38 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,279 kWh a year; one kW of the turbine above makes 1,963. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.5 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.