Wind Turbine Payback in Johnson County, AR
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, AR averages 3.43 m/s (7.7 mph). A 10 kW turbine there would make about 4,056 kWh a year, worth $557 at AR's 13.74¢/kWh. Against an installed cost of about $100,000, that is a payback of over 100 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, 8.4 m/s at the hub against 3.43 m/s here. Per kW, solar panels would make about 1,285 kWh a year here against the turbine's 406, so get a solar quote first.
What would have to change
- Power would have to cost 123¢/kWh, 9.0 times what AR pays now.
- Or the average wind at the hub would have to be 8.4 m/s instead of 3.43. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of AR
Johnson County is the 2,587th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in AR is Mississippi County at 5.35 m/s, payback 49 years.
Month by month in Johnson County
March is the strongest month here, at 3.99 m/s and about 555 kWh. July is the weakest, 2.66 m/s and 145 kWh, so the best month makes 3.8 times the worst. November to March brings in 53% of the year's output in Johnson County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.72 m/s | 446 kWh | $61 |
| February | 3.86 m/s | 450 kWh | $62 |
| March | 3.99 m/s | 555 kWh | $76 |
| April | 4.03 m/s | 554 kWh | $76 |
| May | 3.48 m/s | 360 kWh | $49 |
| June | 3.04 m/s | 224 kWh | $31 |
| July | 2.66 m/s | 145 kWh | $20 |
| August | 2.70 m/s | 152 kWh | $21 |
| September | 3.07 m/s | 232 kWh | $32 |
| October | 3.43 m/s | 344 kWh | $47 |
| November | 3.66 m/s | 411 kWh | $56 |
| December | 3.57 m/s | 393 kWh | $54 |
What a taller tower would buy
Measured at 10 m the wind in Johnson County averages 2.15 m/s; at 50 m it is 4.26 m/s. That gives a shear exponent of 0.425, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 2,276 to 7,953 kWh a year, 249% 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 | 2.89 m/s | 2,276 kWh | over 100 years |
| 30 m | 3.43 m/s | 4,051 kWh | over 100 years |
| 40 m | 3.87 m/s | 5,963 kWh | over 100 years |
| 50 m | 4.26 m/s | 7,953 kWh | 92 years |
Counties around Johnson County
2 of the 6 closest counties are windier at turbine height; the windiest, Madison County, averages 3.63 m/s.
- Franklin County, AR: 3.43 m/s, 4,056 kWh, payback over 100 years (24 mi)
- Pope County, AR: 3.19 m/s, 3,198 kWh, payback over 100 years (26 mi)
- Newton County, AR: 3.49 m/s, 4,289 kWh, payback over 100 years (27 mi)
- Logan County, AR: 3.3 m/s, 3,577 kWh, payback over 100 years (28 mi)
- Madison County, AR: 3.63 m/s, 4,862 kWh, payback over 100 years (34 mi)
- Yell County, AR: 3.24 m/s, 3,367 kWh, payback over 100 years (40 mi)
Sun versus wind in Johnson County
Johnson County gets 4.4 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,285 kWh a year; one kW of the turbine above makes 406. Kilowatt for kilowatt, panels make 3.2 times as much here as the turbine. 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.