Wind Turbine Payback in Buchanan County, IA
Wind turbine payback in Buchanan 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 Buchanan County, IA averages 6.11 m/s (13.7 mph). A 10 kW turbine there would make about 20,520 kWh a year, worth $2,986 at IA's 14.55¢/kWh. Against an installed cost of about $100,000, that is a payback of 34 years, and the turbine is built to last about 20.
What to do in Buchanan County
A home turbine is not worth buying for savings in Buchanan County unless your spot is far windier than the county average, 8.1 m/s at the hub against 6.11 m/s here. Per kW, solar panels would make about 1,156 kWh a year here against the turbine's 2,052, so get a solar quote first.
What would have to change
- Power would have to cost 24¢/kWh, 1.7 times what IA pays now.
- Or the average wind at the hub would have to be 8.1 m/s instead of 6.11. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of IA
Buchanan County is the 675th 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 Buchanan County
April is the strongest month here, at 7.04 m/s and about 2,247 kWh. August is the weakest, 4.80 m/s and 950 kWh, so the best month makes 2.4 times the worst. November to March brings in 48% of the year's output in Buchanan County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.53 m/s | 2,009 kWh | $292 |
| February | 6.61 m/s | 1,855 kWh | $270 |
| March | 6.70 m/s | 2,115 kWh | $308 |
| April | 7.04 m/s | 2,247 kWh | $327 |
| May | 6.31 m/s | 1,870 kWh | $272 |
| June | 5.51 m/s | 1,323 kWh | $192 |
| July | 4.80 m/s | 950 kWh | $138 |
| August | 4.80 m/s | 950 kWh | $138 |
| September | 5.75 m/s | 1,468 kWh | $214 |
| October | 6.40 m/s | 1,926 kWh | $280 |
| November | 6.53 m/s | 1,945 kWh | $283 |
| December | 6.33 m/s | 1,881 kWh | $274 |
What a taller tower would buy
Measured at 10 m the wind in Buchanan County averages 4.77 m/s; at 50 m it is 6.85 m/s. That gives a shear exponent of 0.225, typical of ordinary open country. Going from 20 m to 50 m takes output from 16,571 to 25,964 kWh a year, 57% 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 | 5.57 m/s | 16,571 kWh | 42 years |
| 30 m | 6.11 m/s | 20,492 kWh | 34 years |
| 40 m | 6.51 m/s | 23,514 kWh | 29 years |
| 50 m | 6.85 m/s | 25,964 kWh | 27 years |
Counties around Buchanan County
3 of the 6 closest counties are windier at turbine height; the windiest, Bremer County, averages 6.21 m/s.
- Black Hawk County, IA: 6.17 m/s, 20,965 kWh, payback 33 years (24 mi)
- Delaware County, IA: 6.06 m/s, 20,149 kWh, payback 34 years (24 mi)
- Fayette County, IA: 6.18 m/s, 21,039 kWh, payback 33 years (27 mi)
- Benton County, IA: 6.07 m/s, 20,223 kWh, payback 34 years (28 mi)
- Linn County, IA: 6.07 m/s, 20,223 kWh, payback 34 years (30 mi)
- Bremer County, IA: 6.21 m/s, 21,262 kWh, payback 32 years (33 mi)
Sun versus wind in Buchanan County
Buchanan County gets 3.96 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,156 kWh a year; one kW of the turbine above makes 2,052. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.8 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.