Wind Turbine Payback in DeKalb County, MO
Wind turbine payback in DeKalb 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 DeKalb County, MO averages 5.99 m/s (13.4 mph). A 10 kW turbine there would make about 19,630 kWh a year, worth $2,803 at MO's 14.28¢/kWh. Against an installed cost of about $100,000, that is a payback of 36 years, and the turbine is built to last about 20.
What to do in DeKalb County
A home turbine is not worth buying for savings in DeKalb County unless your spot is far windier than the county average, 8.2 m/s at the hub against 5.99 m/s here. Per kW, solar panels would make about 1,235 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, 1.8 times what MO pays now.
- Or the average wind at the hub would have to be 8.2 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 MO
DeKalb County is the 858th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in MO is Atchison County at 6.17 m/s, payback 33 years.
Month by month in DeKalb County
April is the strongest month here, at 6.89 m/s and about 2,158 kWh. August is the weakest, 4.71 m/s and 903 kWh, so the best month makes 2.4 times the worst. November to March brings in 48% of the year's output in DeKalb County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.38 m/s | 1,911 kWh | $273 |
| February | 6.37 m/s | 1,721 kWh | $246 |
| March | 6.70 m/s | 2,116 kWh | $302 |
| April | 6.89 m/s | 2,158 kWh | $308 |
| May | 6.08 m/s | 1,721 kWh | $246 |
| June | 5.56 m/s | 1,354 kWh | $193 |
| July | 4.78 m/s | 941 kWh | $134 |
| August | 4.71 m/s | 903 kWh | $129 |
| September | 5.55 m/s | 1,349 kWh | $193 |
| October | 6.26 m/s | 1,838 kWh | $262 |
| November | 6.48 m/s | 1,914 kWh | $273 |
| December | 6.22 m/s | 1,810 kWh | $258 |
What a taller tower would buy
Measured at 10 m the wind in DeKalb County averages 4.63 m/s; at 50 m it is 6.76 m/s. That gives a shear exponent of 0.235, typical of ordinary open country. Going from 20 m to 50 m takes output from 15,680 to 25,311 kWh a year, 61% 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 | 5.45 m/s | 15,680 kWh | 45 years |
| 30 m | 6 m/s | 19,669 kWh | 36 years |
| 40 m | 6.41 m/s | 22,777 kWh | 31 years |
| 50 m | 6.76 m/s | 25,311 kWh | 28 years |
Counties around DeKalb County
2 of the 6 closest counties are windier at turbine height; the windiest, Andrew County, averages 6.07 m/s.
- Clinton County, MO: 5.99 m/s, 19,630 kWh, payback 36 years (20 mi)
- Gentry County, MO: 5.99 m/s, 19,630 kWh, payback 36 years (22 mi)
- Andrew County, MO: 6.07 m/s, 20,223 kWh, payback 35 years (22 mi)
- Daviess County, MO: 5.91 m/s, 19,038 kWh, payback 37 years (24 mi)
- Buchanan County, MO: 6.06 m/s, 20,149 kWh, payback 35 years (27 mi)
- Caldwell County, MO: 5.89 m/s, 18,890 kWh, payback 37 years (28 mi)
Sun versus wind in DeKalb County
DeKalb County gets 4.23 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,235 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 1.6 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.