Wind Turbine Payback in Johnson County, MO
Wind turbine payback in Johnson 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 Johnson County, MO averages 5.42 m/s (12.1 mph). A 10 kW turbine there would make about 15,462 kWh a year, worth $2,208 at MO's 14.28¢/kWh. Against an installed cost of about $100,000, that is a payback of 45 years, and the turbine is built to last about 20.
What to do in Johnson County
A home turbine is not worth buying for savings in Johnson County unless your spot is far windier than the county average, 8.2 m/s at the hub against 5.42 m/s here. Per kW, solar panels would make about 1,247 kWh a year here against the turbine's 1,546, so get a solar quote first.
What would have to change
- Power would have to cost 32¢/kWh, 2.3 times what MO pays now.
- Or the average wind at the hub would have to be 8.2 m/s instead of 5.42. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of MO
Johnson County is the 1,264th 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 Johnson County
April is the strongest month here, at 6.33 m/s and about 1,818 kWh. July is the weakest, 4.22 m/s and 658 kWh, so the best month makes 2.8 times the worst. November to March brings in 50% of the year's output in Johnson County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 5.90 m/s | 1,608 kWh | $230 |
| February | 5.93 m/s | 1,472 kWh | $210 |
| March | 6.20 m/s | 1,801 kWh | $257 |
| April | 6.33 m/s | 1,818 kWh | $260 |
| May | 5.42 m/s | 1,315 kWh | $188 |
| June | 4.98 m/s | 1,022 kWh | $146 |
| July | 4.22 m/s | 658 kWh | $94 |
| August | 4.25 m/s | 670 kWh | $96 |
| September | 4.73 m/s | 885 kWh | $126 |
| October | 5.58 m/s | 1,412 kWh | $202 |
| November | 5.90 m/s | 1,562 kWh | $223 |
| December | 5.71 m/s | 1,493 kWh | $213 |
What a taller tower would buy
Measured at 10 m the wind in Johnson County averages 4.08 m/s; at 50 m it is 6.19 m/s. That gives a shear exponent of 0.259, typical of ordinary open country. Going from 20 m to 50 m takes output from 11,749 to 21,113 kWh a year, 80% 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 | 4.88 m/s | 11,749 kWh | 60 years |
| 30 m | 5.42 m/s | 15,483 kWh | 45 years |
| 40 m | 5.84 m/s | 18,539 kWh | 38 years |
| 50 m | 6.19 m/s | 21,113 kWh | 33 years |
Counties around Johnson County
4 of the 6 closest counties are windier at turbine height; the windiest, Jackson County, averages 5.96 m/s.
- Lafayette County, MO: 5.86 m/s, 18,669 kWh, payback 38 years (23 mi)
- Henry County, MO: 5.42 m/s, 15,462 kWh, payback 45 years (25 mi)
- Pettis County, MO: 4.81 m/s, 11,276 kWh, payback 62 years (28 mi)
- Cass County, MO: 5.9 m/s, 18,964 kWh, payback 37 years (30 mi)
- Jackson County, MO: 5.96 m/s, 19,408 kWh, payback 36 years (34 mi)
- Ray County, MO: 5.89 m/s, 18,890 kWh, payback 37 years (40 mi)
Sun versus wind in Johnson County
Johnson County gets 4.27 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,247 kWh a year; one kW of the turbine above makes 1,546. 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.