What factors affect the output of wind turbines?

What factors affect the output of wind turbines?
Wind energy is undoubtedly one of the cleanest forms of producing power from a renewable source. There is no pollution, there is no burning of fossil fuels, and unless something very drastic happens, you don’t run out of wind. But it’s not like you can erect a wind turbine anywhere and it will start generating power for you. There are lots of factors that can make an impact on the amount of energy you can generate out of wind.