Wind Turbine Payback in Worth County, IA
Wind turbine payback in Worth 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 Worth County, IA averages 6.43 m/s (14.4 mph). A 10 kW turbine there would make about 22,891 kWh a year, worth $3,331 at IA's 14.55¢/kWh. Against an installed cost of about $100,000, that is a payback of 30 years, and the turbine is built to last about 20.
What to do in Worth County
A home turbine is not worth buying for savings in Worth County unless your spot is far windier than the county average, 8.1 m/s at the hub against 6.43 m/s here. Per kW, solar panels would make about 1,159 kWh a year here against the turbine's 2,289, so get a solar quote first.
What would have to change
- Power would have to cost 22¢/kWh, 1.5 times what IA pays now.
- Or the average wind at the hub would have to be 8.1 m/s instead of 6.43. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of IA
Worth County is the 290th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in IA is Dickinson County at 6.59 m/s, payback 29 years.
Month by month in Worth County
April is the strongest month here, at 7.28 m/s and about 2,385 kWh. August is the weakest, 5.11 m/s and 1,128 kWh, so the best month makes 2.1 times the worst. November to March brings in 47% of the year's output in Worth County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.92 m/s | 2,248 kWh | $327 |
| February | 6.90 m/s | 2,021 kWh | $294 |
| March | 6.97 m/s | 2,276 kWh | $331 |
| April | 7.28 m/s | 2,385 kWh | $347 |
| May | 6.60 m/s | 2,049 kWh | $298 |
| June | 5.91 m/s | 1,563 kWh | $227 |
| July | 5.15 m/s | 1,149 kWh | $167 |
| August | 5.11 m/s | 1,128 kWh | $164 |
| September | 6.19 m/s | 1,733 kWh | $252 |
| October | 6.67 m/s | 2,094 kWh | $305 |
| November | 6.83 m/s | 2,123 kWh | $309 |
| December | 6.70 m/s | 2,110 kWh | $307 |
What a taller tower would buy
Measured at 10 m the wind in Worth County averages 5.08 m/s; at 50 m it is 7.17 m/s. That gives a shear exponent of 0.214, typical of ordinary open country. Going from 20 m to 50 m takes output from 18,915 to 28,250 kWh a year, 49% 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 | 5.89 m/s | 18,915 kWh | 36 years |
| 30 m | 6.43 m/s | 22,872 kWh | 30 years |
| 40 m | 6.84 m/s | 25,860 kWh | 27 years |
| 50 m | 7.17 m/s | 28,250 kWh | 24 years |
Counties around Worth County
1 of the 6 closest counties is windier at turbine height; the windiest, Winnebago County, averages 6.47 m/s.
- Cerro Gordo County, IA: 6.33 m/s, 22,151 kWh, payback 31 years (21 mi)
- Freeborn County, MN: 6.43 m/s, 22,891 kWh, payback 27 years (21 mi)
- Mitchell County, IA: 6.37 m/s, 22,447 kWh, payback 31 years (23 mi)
- Winnebago County, IA: 6.47 m/s, 23,186 kWh, payback 30 years (25 mi)
- Mower County, MN: 6.37 m/s, 22,447 kWh, payback 27 years (32 mi)
- Floyd County, IA: 6.21 m/s, 21,262 kWh, payback 32 years (32 mi)
Sun versus wind in Worth County
Worth County gets 3.97 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,159 kWh a year; one kW of the turbine above makes 2,289. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 2.0 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.