Wind Turbine Payback in Cook County, IL
Wind turbine payback in Cook 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 Cook County, IL averages 6.73 m/s (15.1 mph). A 10 kW turbine there would make about 25,093 kWh a year, worth $4,825 at IL's 19.23¢/kWh. Against an installed cost of about $100,000, that is a payback of 21 years, and the turbine is built to last about 20.
What to do in Cook County
A home turbine is not worth buying for savings in Cook County unless your spot is far windier than the county average, 6.8 m/s at the hub against 6.73 m/s here. Per kW, solar panels would make about 1,121 kWh a year here against the turbine's 2,509, so get a solar quote first.
What would have to change
- Power would have to cost 20¢/kWh, 1.0 times what IL pays now.
- Or the average wind at the hub would have to be 6.8 m/s instead of 6.73. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of IL
Cook County is the 46th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. It is the windiest county in IL.
Month by month in Cook County
January is the strongest month here, at 7.79 m/s and about 2,759 kWh. August is the weakest, 5.02 m/s and 1,074 kWh, so the best month makes 2.6 times the worst. November to March brings in 51% of the year's output in Cook County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 7.79 m/s | 2,759 kWh | $531 |
| February | 7.50 m/s | 2,345 kWh | $451 |
| March | 7.22 m/s | 2,429 kWh | $467 |
| April | 7.43 m/s | 2,471 kWh | $475 |
| May | 6.61 m/s | 2,057 kWh | $396 |
| June | 5.72 m/s | 1,448 kWh | $278 |
| July | 5.10 m/s | 1,122 kWh | $216 |
| August | 5.02 m/s | 1,074 kWh | $207 |
| September | 5.98 m/s | 1,610 kWh | $310 |
| October | 7.17 m/s | 2,401 kWh | $462 |
| November | 7.67 m/s | 2,604 kWh | $501 |
| December | 7.59 m/s | 2,644 kWh | $508 |
What a taller tower would buy
Measured at 10 m the wind in Cook County averages 5.65 m/s; at 50 m it is 7.3 m/s. That gives a shear exponent of 0.159, typical of very open, smooth ground where height adds little. Going from 20 m to 50 m takes output from 22,005 to 29,160 kWh a year, 33% 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 | 6.31 m/s | 22,005 kWh | 24 years |
| 30 m | 6.73 m/s | 25,097 kWh | 21 years |
| 40 m | 7.05 m/s | 27,368 kWh | 19 years |
| 50 m | 7.3 m/s | 29,160 kWh | 18 years |
Counties around Cook County
None of the 6 closest counties is windier than Cook County.
- Lake County, IL: 6.73 m/s, 25,093 kWh, payback 21 years (22 mi)
- DuPage County, IL: 6.12 m/s, 20,594 kWh, payback 25 years (23 mi)
- Lake County, IN: 6.17 m/s, 20,965 kWh, payback 28 years (32 mi)
- Will County, IL: 5.98 m/s, 19,556 kWh, payback 27 years (35 mi)
- Porter County, IN: 6.1 m/s, 20,446 kWh, payback 29 years (40 mi)
- Kane County, IL: 6.12 m/s, 20,594 kWh, payback 25 years (40 mi)
Sun versus wind in Cook County
Cook County gets 3.84 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,121 kWh a year; one kW of the turbine above makes 2,509. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 2.2 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.