Hello, As wind speed rises, the power output of wind turbine also rises. However, after it reaches a certain value (rated power), it levels off, i.e., it doesn't increase any further. According to my teacher, there is a limit to the power generation capability of the generator and hence the output power does not go beyond a certain value. However, he also said that we have to use gear mechanisms to keep the output power at that value. I saw nearly the same description on this website: http://www.wind-power-program.com/turbine_characteristics.htm Problem is, I see a contradiction in this description. If the capability of the generator is already limited, then why do we also have to deliberately design the turbine (using gear mechanisms etc.) in such a way as to maintain the output at the rated value? Thank you.