Which better ( Wind Turbines , Photovoltaics Solar Energy ) and why ?

Well, Wind turbines are cheaper per Watt produced but it requires more maintenance, and more knowledge and technology required,

Wind turbines production depends on wind speed which is not easily predicted and repetitive

Solar on the other hand is a bit more expensive but less maintenance and technology required, Solar radiation is more predictable.

wind turbines is better and why ?

its rpm can be controlled by equation d1/d2 =n1/n2

 solar cells is better in a places that the sun is strong such as middle east and Africa but wind turbines is better in places  that wind is strong