Wind Turbine Payback in Polk County, AR
Wind turbine payback in Polk 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 Polk County, AR averages 3.35 m/s (7.5 mph). A 10 kW turbine there would make about 3,757 kWh a year, worth $516 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 Polk County
A home turbine is not worth buying for savings in Polk County unless your spot is far windier than the county average, 8.4 m/s at the hub against 3.35 m/s here. Per kW, solar panels would make about 1,288 kWh a year here against the turbine's 376, so get a solar quote first.
What would have to change
- Power would have to cost 133¢/kWh, 9.7 times what AR pays now.
- Or the average wind at the hub would have to be 8.4 m/s instead of 3.35. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of AR
Polk County is the 2,683rd 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 Polk County
April is the strongest month here, at 3.91 m/s and about 505 kWh. August is the weakest, 2.70 m/s and 153 kWh, so the best month makes 3.3 times the worst. November to March brings in 51% of the year's output in Polk County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.55 m/s | 385 kWh | $53 |
| February | 3.63 m/s | 373 kWh | $51 |
| March | 3.82 m/s | 484 kWh | $67 |
| April | 3.91 m/s | 505 kWh | $69 |
| May | 3.46 m/s | 353 kWh | $49 |
| June | 3.06 m/s | 229 kWh | $31 |
| July | 2.70 m/s | 153 kWh | $21 |
| August | 2.70 m/s | 153 kWh | $21 |
| September | 3.00 m/s | 214 kWh | $29 |
| October | 3.35 m/s | 320 kWh | $44 |
| November | 3.57 m/s | 381 kWh | $52 |
| December | 3.46 m/s | 353 kWh | $49 |
What a taller tower would buy
Measured at 10 m the wind in Polk County averages 2 m/s; at 50 m it is 4.25 m/s. That gives a shear exponent of 0.468, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 1,965 to 7,897 kWh a year, 302% 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 | 2.77 m/s | 1,965 kWh | over 100 years |
| 30 m | 3.35 m/s | 3,743 kWh | over 100 years |
| 40 m | 3.83 m/s | 5,747 kWh | over 100 years |
| 50 m | 4.25 m/s | 7,897 kWh | 92 years |
Counties around Polk County
3 of the 6 closest counties are windier at turbine height; the windiest, Le Flore County, averages 4 m/s.
- Scott County, AR: 3.58 m/s, 4,653 kWh, payback over 100 years (27 mi)
- Howard County, AR: 3.28 m/s, 3,506 kWh, payback over 100 years (31 mi)
- Montgomery County, AR: 3.31 m/s, 3,612 kWh, payback over 100 years (32 mi)
- Sevier County, AR: 3.54 m/s, 4,489 kWh, payback over 100 years (34 mi)
- Le Flore County, OK: 4 m/s, 6,577 kWh, payback over 100 years (39 mi)
- Pike County, AR: 3.28 m/s, 3,506 kWh, payback over 100 years (40 mi)
Sun versus wind in Polk County
Polk County gets 4.41 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,288 kWh a year; one kW of the turbine above makes 376. Kilowatt for kilowatt, panels make 3.4 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.