Question

A wind turbine designer is considering installing a horizontal axis wind turbine at a location in Michigan. To increase the power extracted from wind, the designer is debating between increasing the blade radius by 10% versus increasing the height from 40 m to 60 m, which would increase the average wind speed from 6 mph to 6.5 mph. Considering the only the impact on power extraction, the designer should go with the height increase.
a. True
b. False

Answer 1

Answer:

False ( B )

Explanation:

considering that the wind turbine is a horizontal axis turbine

Power generated/extracted by the turbine can be calculated as

P =  n * 1/2 * p *Av^3

where: n = turbine efficiency

           p = air density

           A = πd^2 / 4

           v =  speed

From the above equation it can seen that increasing the Blade radius by 10% will increase the Blade Area which will in turn increase the value of the power extracted by the wind turbine