Solar Fan Kits are Great for Green Houses, Kennels, Barns and Attics Where Ac Power is Not Available. the Solar Module Runs the Fan At Full Power in Full Sun and At a Slower Speed in Overcast Weather. Operation is Automatic. When the Sun Shines On the Solar Module, the Fan Begins to Operate. the Reversible, Ball Bearing Pm Motor Allows the Fan to Be Used for Intake or Exhaust By Reversing the Wire At the Motor. We have Soalr Fans for You