Wind Turbine Payback in Coffey County, KS
Wind turbine payback in Coffey 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 Coffey County, KS averages 6.18 m/s (13.8 mph). A 10 kW turbine there would make about 21,039 kWh a year, worth $3,211 at KS's 15.26¢/kWh. Against an installed cost of about $100,000, that is a payback of 31 years, and the turbine is built to last about 20.
What to do in Coffey County
A home turbine is not worth buying for savings in Coffey County unless your spot is far windier than the county average, 7.8 m/s at the hub against 6.18 m/s here. Per kW, solar panels would make about 1,276 kWh a year here against the turbine's 2,104, so get a solar quote first.
What would have to change
- Power would have to cost 24¢/kWh, 1.6 times what KS pays now.
- Or the average wind at the hub would have to be 7.8 m/s instead of 6.18. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of KS
Coffey County is the 599th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in KS is Edwards County at 6.68 m/s, payback 27 years.
Month by month in Coffey County
April is the strongest month here, at 7.24 m/s and about 2,362 kWh. August is the weakest, 4.91 m/s and 1,015 kWh, so the best month makes 2.3 times the worst. November to March brings in 47% of the year's output in Coffey County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.45 m/s | 1,956 kWh | $298 |
| February | 6.50 m/s | 1,797 kWh | $274 |
| March | 6.94 m/s | 2,259 kWh | $345 |
| April | 7.24 m/s | 2,362 kWh | $360 |
| May | 6.24 m/s | 1,827 kWh | $279 |
| June | 5.90 m/s | 1,557 kWh | $238 |
| July | 4.99 m/s | 1,060 kWh | $162 |
| August | 4.91 m/s | 1,015 kWh | $155 |
| September | 5.56 m/s | 1,354 kWh | $207 |
| October | 6.42 m/s | 1,939 kWh | $296 |
| November | 6.68 m/s | 2,032 kWh | $310 |
| December | 6.38 m/s | 1,911 kWh | $292 |
What a taller tower would buy
Measured at 10 m the wind in Coffey County averages 4.79 m/s; at 50 m it is 6.96 m/s. That gives a shear exponent of 0.232, typical of ordinary open country. Going from 20 m to 50 m takes output from 16,959 to 26,756 kWh a year, 58% 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 | 5.63 m/s | 16,959 kWh | 39 years |
| 30 m | 6.18 m/s | 21,055 kWh | 31 years |
| 40 m | 6.61 m/s | 24,207 kWh | 27 years |
| 50 m | 6.96 m/s | 26,756 kWh | 25 years |
Counties around Coffey County
2 of the 6 closest counties are windier at turbine height; the windiest, Lyon County, averages 6.38 m/s.
- Anderson County, KS: 6.03 m/s, 19,926 kWh, payback 33 years (24 mi)
- Woodson County, KS: 6.18 m/s, 21,039 kWh, payback 31 years (24 mi)
- Lyon County, KS: 6.38 m/s, 22,521 kWh, payback 29 years (28 mi)
- Osage County, KS: 6.22 m/s, 21,336 kWh, payback 31 years (29 mi)
- Franklin County, KS: 6.06 m/s, 20,149 kWh, payback 33 years (33 mi)
- Allen County, KS: 6.03 m/s, 19,926 kWh, payback 33 years (34 mi)
Sun versus wind in Coffey County
Coffey County gets 4.37 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,276 kWh a year; one kW of the turbine above makes 2,104. 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.