Wind Turbine Payback in Todd County, SD
Wind turbine payback in Todd 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 Todd County, SD averages 6.77 m/s (15.1 mph). A 10 kW turbine there would make about 25,384 kWh a year, worth $3,701 at SD's 14.58¢/kWh. Against an installed cost of about $100,000, that is a payback of 27 years, and the turbine is built to last about 20.
What to do in Todd County
A home turbine is not worth buying for savings in Todd County unless your spot is far windier than the county average, 8.1 m/s at the hub against 6.77 m/s here. Per kW, solar panels would make about 1,253 kWh a year here against the turbine's 2,538, 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 6.77. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of SD
Todd County is the 38th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. It is the windiest county in SD.
Month by month in Todd County
January is the strongest month here, at 7.40 m/s and about 2,536 kWh. July is the weakest, 5.76 m/s and 1,525 kWh, so the best month makes 1.7 times the worst. November to March brings in 46% of the year's output in Todd County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 7.40 m/s | 2,536 kWh | $370 |
| February | 6.98 m/s | 2,062 kWh | $301 |
| March | 7.00 m/s | 2,294 kWh | $334 |
| April | 7.18 m/s | 2,330 kWh | $340 |
| May | 6.73 m/s | 2,134 kWh | $311 |
| June | 6.12 m/s | 1,695 kWh | $247 |
| July | 5.76 m/s | 1,525 kWh | $222 |
| August | 5.87 m/s | 1,593 kWh | $232 |
| September | 6.65 m/s | 2,011 kWh | $293 |
| October | 7.09 m/s | 2,349 kWh | $342 |
| November | 7.22 m/s | 2,351 kWh | $343 |
| December | 7.28 m/s | 2,467 kWh | $360 |
What a taller tower would buy
Measured at 10 m the wind in Todd County averages 5.39 m/s; at 50 m it is 7.53 m/s. That gives a shear exponent of 0.208, typical of ordinary open country. Going from 20 m to 50 m takes output from 21,360 to 30,739 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 | 6.22 m/s | 21,360 kWh | 32 years |
| 30 m | 6.77 m/s | 25,391 kWh | 27 years |
| 40 m | 7.19 m/s | 28,380 kWh | 24 years |
| 50 m | 7.53 m/s | 30,739 kWh | 22 years |
Counties around Todd County
1 of the 6 closest counties is windier at turbine height; the windiest, Cherry County, averages 6.83 m/s.
- Mellette County, SD: 6.55 m/s, 23,775 kWh, payback 29 years (26 mi)
- Tripp County, SD: 6.49 m/s, 23,333 kWh, payback 29 years (43 mi)
- Cherry County, NE: 6.83 m/s, 25,819 kWh, payback 30 years (47 mi)
- Bennett County, SD: 6.73 m/s, 25,093 kWh, payback 27 years (49 mi)
- Jones County, SD: 6.34 m/s, 22,225 kWh, payback 31 years (51 mi)
- Keya Paha County, NE: 6.73 m/s, 25,093 kWh, payback 31 years (55 mi)
Sun versus wind in Todd County
Todd County gets 4.29 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,253 kWh a year; one kW of the turbine above makes 2,538. 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.