Wind Turbine Payback in Monona County, IA
Wind turbine payback in Monona 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 Monona County, IA averages 6.39 m/s (14.3 mph). A 10 kW turbine there would make about 22,595 kWh a year, worth $3,288 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 Monona County
A home turbine is not worth buying for savings in Monona County unless your spot is far windier than the county average, 8.1 m/s at the hub against 6.39 m/s here. Per kW, solar panels would make about 1,206 kWh a year here against the turbine's 2,260, 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 6.39. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of IA
Monona County is the 347th 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 Monona County
April is the strongest month here, at 7.26 m/s and about 2,371 kWh. July is the weakest, 5.25 m/s and 1,212 kWh, so the best month makes 2.0 times the worst. November to March brings in 45% of the year's output in Monona County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.64 m/s | 2,074 kWh | $302 |
| February | 6.64 m/s | 1,873 kWh | $273 |
| March | 6.86 m/s | 2,212 kWh | $322 |
| April | 7.26 m/s | 2,371 kWh | $345 |
| May | 6.60 m/s | 2,052 kWh | $299 |
| June | 6.02 m/s | 1,632 kWh | $237 |
| July | 5.25 m/s | 1,212 kWh | $176 |
| August | 5.27 m/s | 1,222 kWh | $178 |
| September | 6.33 m/s | 1,823 kWh | $265 |
| October | 6.66 m/s | 2,091 kWh | $304 |
| November | 6.74 m/s | 2,066 kWh | $301 |
| December | 6.49 m/s | 1,979 kWh | $288 |
What a taller tower would buy
Measured at 10 m the wind in Monona County averages 5.03 m/s; at 50 m it is 7.14 m/s. That gives a shear exponent of 0.218, typical of ordinary open country. Going from 20 m to 50 m takes output from 18,574 to 28,038 kWh a year, 51% 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 | 5.85 m/s | 18,574 kWh | 37 years |
| 30 m | 6.39 m/s | 22,577 kWh | 30 years |
| 40 m | 6.8 m/s | 25,609 kWh | 27 years |
| 50 m | 7.14 m/s | 28,038 kWh | 25 years |
Counties around Monona County
2 of the 6 closest counties are windier at turbine height; the windiest, Ida County, averages 6.44 m/s.
- Burt County, NE: 6.39 m/s, 22,595 kWh, payback 34 years (24 mi)
- Woodbury County, IA: 6.4 m/s, 22,669 kWh, payback 30 years (24 mi)
- Harrison County, IA: 6.31 m/s, 22,003 kWh, payback 31 years (26 mi)
- Crawford County, IA: 6.39 m/s, 22,595 kWh, payback 30 years (29 mi)
- Thurston County, NE: 6.39 m/s, 22,595 kWh, payback 34 years (30 mi)
- Ida County, IA: 6.44 m/s, 22,964 kWh, payback 30 years (33 mi)
Sun versus wind in Monona County
Monona County gets 4.13 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,206 kWh a year; one kW of the turbine above makes 2,260. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.9 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.