Wind Turbine Payback in Champaign County, IL
Wind turbine payback in Champaign 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 Champaign County, IL averages 6 m/s (13.4 mph). A 10 kW turbine there would make about 19,704 kWh a year, worth $3,789 at IL's 19.23¢/kWh. Against an installed cost of about $100,000, that is a payback of 26 years, and the turbine is built to last about 20.
What to do in Champaign County
A home turbine is not worth buying for savings in Champaign County unless your spot is far windier than the county average, 6.8 m/s at the hub against 6 m/s here. Per kW, solar panels would make about 1,174 kWh a year here against the turbine's 1,970, so get a solar quote first.
What would have to change
- Power would have to cost 25¢/kWh, 1.3 times what IL pays now.
- Or the average wind at the hub would have to be 6.8 m/s instead of 6. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of IL
Champaign County is the 840th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in IL is Cook County at 6.73 m/s, payback 21 years.
Month by month in Champaign County
April is the strongest month here, at 7.04 m/s and about 2,247 kWh. July is the weakest, 4.52 m/s and 802 kWh, so the best month makes 2.8 times the worst. November to March brings in 51% of the year's output in Champaign County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.70 m/s | 2,115 kWh | $407 |
| February | 6.65 m/s | 1,881 kWh | $362 |
| March | 6.71 m/s | 2,121 kWh | $408 |
| April | 7.04 m/s | 2,247 kWh | $432 |
| May | 6.07 m/s | 1,719 kWh | $331 |
| June | 5.25 m/s | 1,169 kWh | $225 |
| July | 4.52 m/s | 802 kWh | $154 |
| August | 4.53 m/s | 806 kWh | $155 |
| September | 5.14 m/s | 1,108 kWh | $213 |
| October | 6.25 m/s | 1,831 kWh | $352 |
| November | 6.70 m/s | 2,047 kWh | $394 |
| December | 6.52 m/s | 1,999 kWh | $384 |
What a taller tower would buy
Measured at 10 m the wind in Champaign County averages 4.66 m/s; at 50 m it is 6.75 m/s. That gives a shear exponent of 0.230, typical of ordinary open country. Going from 20 m to 50 m takes output from 15,802 to 25,239 kWh a year, 60% 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 | 5.47 m/s | 15,802 kWh | 33 years |
| 30 m | 6 m/s | 19,717 kWh | 26 years |
| 40 m | 6.41 m/s | 22,760 kWh | 23 years |
| 50 m | 6.75 m/s | 25,239 kWh | 21 years |
Counties around Champaign County
3 of the 6 closest counties are windier at turbine height; the windiest, Ford County, averages 6.07 m/s.
- Piatt County, IL: 6.04 m/s, 20,001 kWh, payback 26 years (23 mi)
- Vermilion County, IL: 5.9 m/s, 18,964 kWh, payback 27 years (25 mi)
- Douglas County, IL: 6 m/s, 19,704 kWh, payback 26 years (26 mi)
- Ford County, IL: 6.07 m/s, 20,223 kWh, payback 26 years (32 mi)
- De Witt County, IL: 6.04 m/s, 20,001 kWh, payback 26 years (37 mi)
- Edgar County, IL: 5.76 m/s, 17,932 kWh, payback 29 years (40 mi)
Sun versus wind in Champaign County
Champaign County gets 4.02 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,174 kWh a year; one kW of the turbine above makes 1,970. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.7 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.