TurbinePayback

Wind Turbine Payback in Vernon County, WI

Wind turbine payback in Vernon 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 Vernon County, WI averages 6.09 m/s (13.6 mph). A 10 kW turbine there would make about 20,371 kWh a year, worth $3,881 at WI's 19.05¢/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 Vernon County

A home turbine is not worth buying for savings in Vernon County unless your spot is far windier than the county average, 6.9 m/s at the hub against 6.09 m/s here. Per kW, solar panels would make about 1,133 kWh a year here against the turbine's 2,037, so get a solar quote first.

What would have to change

Against the rest of WI

Vernon County is the 701st windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in WI is Manitowoc County at 7.32 m/s, payback 18 years.

Month by month in Vernon County

April is the strongest month here, at 6.86 m/s and about 2,138 kWh. August is the weakest, 4.90 m/s and 1,009 kWh, so the best month makes 2.1 times the worst. November to March brings in 48% of the year's output in Vernon County.

MonthWind at 30 mOutputWorth
January6.60 m/s2,049 kWh$390
February6.74 m/s1,931 kWh$368
March6.53 m/s2,004 kWh$382
April6.86 m/s2,138 kWh$407
May6.13 m/s1,758 kWh$335
June5.54 m/s1,344 kWh$256
July4.97 m/s1,049 kWh$200
August4.90 m/s1,009 kWh$192
September5.79 m/s1,489 kWh$284
October6.39 m/s1,921 kWh$366
November6.41 m/s1,869 kWh$356
December6.26 m/s1,836 kWh$350

What a taller tower would buy

Measured at 10 m the wind in Vernon County averages 4.77 m/s; at 50 m it is 6.82 m/s. That gives a shear exponent of 0.222, typical of ordinary open country. Going from 20 m to 50 m takes output from 16,505 to 25,747 kWh a year, 56% more, before counting the extra cost of the taller tower. Why tower height decides it explains the shear behind these numbers.

Hub heightAverage windOutputPayback
20 m5.56 m/s16,505 kWh32 years
30 m6.09 m/s20,363 kWh26 years
40 m6.49 m/s23,336 kWh23 years
50 m6.82 m/s25,747 kWh20 years

Counties around Vernon County

None of the 6 closest counties is windier than Vernon County.

Sun versus wind in Vernon County

Vernon County gets 3.88 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,133 kWh a year; one kW of the turbine above makes 2,037. 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.