Wind Turbine Payback in Jasper County, IL
Wind turbine payback in Jasper 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 Jasper County, IL averages 5.73 m/s (12.8 mph). A 10 kW turbine there would make about 17,712 kWh a year, worth $3,406 at IL's 19.23¢/kWh. Against an installed cost of about $100,000, that is a payback of 29 years, and the turbine is built to last about 20.
What to do in Jasper County
A home turbine is not worth buying for savings in Jasper County unless your spot is far windier than the county average, 6.8 m/s at the hub against 5.73 m/s here. Per kW, solar panels would make about 1,188 kWh a year here against the turbine's 1,771, so get a solar quote first.
What would have to change
- Power would have to cost 28¢/kWh, 1.5 times what IL pays now.
- Or the average wind at the hub would have to be 6.8 m/s instead of 5.73. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of IL
Jasper County is the 1,121st 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 Jasper County
April is the strongest month here, at 6.77 m/s and about 2,086 kWh. August is the weakest, 4.27 m/s and 679 kWh, so the best month makes 3.1 times the worst. November to March brings in 52% of the year's output in Jasper County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.46 m/s | 1,963 kWh | $377 |
| February | 6.44 m/s | 1,763 kWh | $339 |
| March | 6.56 m/s | 2,024 kWh | $389 |
| April | 6.77 m/s | 2,086 kWh | $401 |
| May | 5.77 m/s | 1,530 kWh | $294 |
| June | 4.96 m/s | 1,007 kWh | $194 |
| July | 4.27 m/s | 679 kWh | $131 |
| August | 4.27 m/s | 679 kWh | $131 |
| September | 4.82 m/s | 930 kWh | $179 |
| October | 5.93 m/s | 1,629 kWh | $313 |
| November | 6.36 m/s | 1,841 kWh | $354 |
| December | 6.22 m/s | 1,813 kWh | $349 |
What a taller tower would buy
Measured at 10 m the wind in Jasper County averages 4.39 m/s; at 50 m it is 6.48 m/s. That gives a shear exponent of 0.242, typical of ordinary open country. Going from 20 m to 50 m takes output from 13,846 to 23,260 kWh a year, 68% 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 | 5.19 m/s | 13,846 kWh | 38 years |
| 30 m | 5.73 m/s | 17,686 kWh | 29 years |
| 40 m | 6.14 m/s | 20,737 kWh | 25 years |
| 50 m | 6.48 m/s | 23,260 kWh | 22 years |
Counties around Jasper County
3 of the 6 closest counties are windier at turbine height; the windiest, Cumberland County, averages 5.91 m/s.
- Cumberland County, IL: 5.91 m/s, 19,038 kWh, payback 27 years (19 mi)
- Richland County, IL: 5.61 m/s, 16,834 kWh, payback 31 years (21 mi)
- Crawford County, IL: 5.61 m/s, 16,834 kWh, payback 31 years (21 mi)
- Effingham County, IL: 5.82 m/s, 18,374 kWh, payback 28 years (24 mi)
- Clay County, IL: 5.71 m/s, 17,565 kWh, payback 30 years (25 mi)
- Clark County, IL: 5.76 m/s, 17,932 kWh, payback 29 years (30 mi)
Sun versus wind in Jasper County
Jasper County gets 4.07 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,188 kWh a year; one kW of the turbine above makes 1,771. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.5 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.