Wind Turbine Payback in Lawrence County, SD
Wind turbine payback in Lawrence 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 Lawrence County, SD averages 5.27 m/s (11.8 mph). A 10 kW turbine there would make about 14,397 kWh a year, worth $2,099 at SD's 14.58¢/kWh. Against an installed cost of about $100,000, that is a payback of 48 years, and the turbine is built to last about 20.
What to do in Lawrence County
A home turbine is not worth buying for savings in Lawrence County unless your spot is far windier than the county average, 8.1 m/s at the hub against 5.27 m/s here. Per kW, solar panels would make about 1,241 kWh a year here against the turbine's 1,440, so get a solar quote first.
What would have to change
- Power would have to cost 35¢/kWh, 2.4 times what SD pays now.
- Or the average wind at the hub would have to be 8.1 m/s instead of 5.27. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of SD
Lawrence County is the 1,333rd 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 Lawrence County
January is the strongest month here, at 6.03 m/s and about 1,694 kWh. July is the weakest, 4.35 m/s and 716 kWh, so the best month makes 2.4 times the worst. November to March brings in 51% of the year's output in Lawrence County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.03 m/s | 1,694 kWh | $247 |
| February | 5.56 m/s | 1,263 kWh | $184 |
| March | 5.50 m/s | 1,361 kWh | $198 |
| April | 5.36 m/s | 1,236 kWh | $180 |
| May | 5.13 m/s | 1,139 kWh | $166 |
| June | 4.72 m/s | 882 kWh | $129 |
| July | 4.35 m/s | 716 kWh | $104 |
| August | 4.50 m/s | 794 kWh | $116 |
| September | 4.95 m/s | 1,002 kWh | $146 |
| October | 5.56 m/s | 1,398 kWh | $204 |
| November | 5.71 m/s | 1,446 kWh | $211 |
| December | 5.86 m/s | 1,586 kWh | $231 |
What a taller tower would buy
Measured at 10 m the wind in Lawrence County averages 3.81 m/s; at 50 m it is 6.12 m/s. That gives a shear exponent of 0.294, typical of ordinary open country. Going from 20 m to 50 m takes output from 10,412 to 20,594 kWh a year, 98% 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 | 4.67 m/s | 10,412 kWh | 66 years |
| 30 m | 5.27 m/s | 14,373 kWh | 48 years |
| 40 m | 5.73 m/s | 17,722 kWh | 39 years |
| 50 m | 6.12 m/s | 20,594 kWh | 33 years |
Counties around Lawrence County
6 of the 6 closest counties are windier at turbine height; the windiest, Meade County, averages 6.32 m/s.
- Butte County, SD: 6.15 m/s, 20,816 kWh, payback 33 years (41 mi)
- Crook County, WY: 5.61 m/s, 16,834 kWh, payback 42 years (41 mi)
- Custer County, SD: 5.58 m/s, 16,616 kWh, payback 41 years (49 mi)
- Weston County, WY: 5.46 m/s, 15,749 kWh, payback 45 years (51 mi)
- Pennington County, SD: 5.76 m/s, 17,932 kWh, payback 38 years (54 mi)
- Meade County, SD: 6.32 m/s, 22,077 kWh, payback 31 years (57 mi)
Sun versus wind in Lawrence County
Lawrence County gets 4.25 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,241 kWh a year; one kW of the turbine above makes 1,440. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.2 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.