Wind Turbine Payback in Lewis County, MO
Wind turbine payback in Lewis 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 Lewis County, MO averages 5.77 m/s (12.9 mph). A 10 kW turbine there would make about 18,006 kWh a year, worth $2,571 at MO's 14.28¢/kWh. Against an installed cost of about $100,000, that is a payback of 39 years, and the turbine is built to last about 20.
What to do in Lewis County
A home turbine is not worth buying for savings in Lewis County unless your spot is far windier than the county average, 8.2 m/s at the hub against 5.77 m/s here. Per kW, solar panels would make about 1,191 kWh a year here against the turbine's 1,801, so get a solar quote first.
What would have to change
- Power would have to cost 28¢/kWh, 1.9 times what MO pays now.
- Or the average wind at the hub would have to be 8.2 m/s instead of 5.77. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of MO
Lewis County is the 1,088th 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 Lewis County
April is the strongest month here, at 6.66 m/s and about 2,018 kWh. August is the weakest, 4.48 m/s and 782 kWh, so the best month makes 2.6 times the worst. November to March brings in 50% of the year's output in Lewis County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.35 m/s | 1,891 kWh | $270 |
| February | 6.30 m/s | 1,683 kWh | $240 |
| March | 6.48 m/s | 1,975 kWh | $282 |
| April | 6.66 m/s | 2,018 kWh | $288 |
| May | 5.76 m/s | 1,524 kWh | $218 |
| June | 5.18 m/s | 1,130 kWh | $161 |
| July | 4.52 m/s | 805 kWh | $115 |
| August | 4.48 m/s | 782 kWh | $112 |
| September | 5.12 m/s | 1,100 kWh | $157 |
| October | 5.99 m/s | 1,668 kWh | $238 |
| November | 6.35 m/s | 1,836 kWh | $262 |
| December | 6.14 m/s | 1,763 kWh | $252 |
What a taller tower would buy
Measured at 10 m the wind in Lewis County averages 4.44 m/s; at 50 m it is 6.52 m/s. That gives a shear exponent of 0.239, typical of ordinary open country. Going from 20 m to 50 m takes output from 14,170 to 23,554 kWh a year, 66% 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 | 5.24 m/s | 14,170 kWh | 49 years |
| 30 m | 5.77 m/s | 18,010 kWh | 39 years |
| 40 m | 6.18 m/s | 21,049 kWh | 33 years |
| 50 m | 6.52 m/s | 23,554 kWh | 30 years |
Counties around Lewis County
3 of the 6 closest counties are windier at turbine height; the windiest, Adams County, averages 5.85 m/s.
- Marion County, MO: 5.77 m/s, 18,006 kWh, payback 39 years (20 mi)
- Clark County, MO: 5.84 m/s, 18,521 kWh, payback 38 years (22 mi)
- Knox County, MO: 5.77 m/s, 18,006 kWh, payback 39 years (22 mi)
- Shelby County, MO: 5.77 m/s, 18,006 kWh, payback 39 years (28 mi)
- Adams County, IL: 5.85 m/s, 18,595 kWh, payback 28 years (29 mi)
- Scotland County, MO: 5.84 m/s, 18,521 kWh, payback 38 years (33 mi)
Sun versus wind in Lewis County
Lewis County gets 4.08 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,191 kWh a year; one kW of the turbine above makes 1,801. 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.