Wind Turbine Payback in Fulton County, IL
Wind turbine payback in Fulton 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 Fulton County, IL averages 5.94 m/s (13.3 mph). A 10 kW turbine there would make about 19,260 kWh a year, worth $3,704 at IL's 19.23¢/kWh. Against an installed cost of about $100,000, that is a payback of 27 years, and the turbine is built to last about 20.
What to do in Fulton County
A home turbine is not worth buying for savings in Fulton County unless your spot is far windier than the county average, 6.8 m/s at the hub against 5.94 m/s here. Per kW, solar panels would make about 1,186 kWh a year here against the turbine's 1,926, so get a solar quote first.
What would have to change
- Power would have to cost 26¢/kWh, 1.4 times what IL pays now.
- Or the average wind at the hub would have to be 6.8 m/s instead of 5.94. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of IL
Fulton County is the 934th 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 Fulton County
April is the strongest month here, at 6.93 m/s and about 2,179 kWh. July is the weakest, 4.56 m/s and 825 kWh, so the best month makes 2.6 times the worst. November to March brings in 50% of the year's output in Fulton County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.50 m/s | 1,988 kWh | $382 |
| February | 6.46 m/s | 1,775 kWh | $341 |
| March | 6.65 m/s | 2,082 kWh | $400 |
| April | 6.93 m/s | 2,179 kWh | $419 |
| May | 6.00 m/s | 1,675 kWh | $322 |
| June | 5.28 m/s | 1,190 kWh | $229 |
| July | 4.56 m/s | 825 kWh | $159 |
| August | 4.57 m/s | 829 kWh | $159 |
| September | 5.26 m/s | 1,180 kWh | $227 |
| October | 6.22 m/s | 1,809 kWh | $348 |
| November | 6.55 m/s | 1,956 kWh | $376 |
| December | 6.32 m/s | 1,876 kWh | $361 |
What a taller tower would buy
Measured at 10 m the wind in Fulton County averages 4.61 m/s; at 50 m it is 6.68 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 15,395 to 24,728 kWh a year, 61% 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 | 5.41 m/s | 15,395 kWh | 34 years |
| 30 m | 5.94 m/s | 19,256 kWh | 27 years |
| 40 m | 6.35 m/s | 22,268 kWh | 23 years |
| 50 m | 6.68 m/s | 24,728 kWh | 21 years |
Counties around Fulton County
2 of the 6 closest counties are windier at turbine height; the windiest, Peoria County, averages 6.03 m/s.
- Mason County, IL: 5.88 m/s, 18,816 kWh, payback 28 years (22 mi)
- McDonough County, IL: 5.94 m/s, 19,260 kWh, payback 27 years (25 mi)
- Schuyler County, IL: 5.85 m/s, 18,595 kWh, payback 28 years (30 mi)
- Peoria County, IL: 6.03 m/s, 19,926 kWh, payback 26 years (32 mi)
- Knox County, IL: 6.03 m/s, 19,926 kWh, payback 26 years (32 mi)
- Cass County, IL: 5.88 m/s, 18,816 kWh, payback 28 years (34 mi)
Sun versus wind in Fulton County
Fulton County gets 4.06 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,186 kWh a year; one kW of the turbine above makes 1,926. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.6 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.