An air cooled oil-free centrifugal chiller system and method, the system comprising at least one AC condenser fan; at least one solar panel; at least one AC/DC convertible fan connected to the at least one solar panel; and a controller configured to determine when sufficient DC power is available and activating the at least one AC/DC convertible fan when sufficient DC power is available, and when DC power is not sufficient, activating the at least one AC condenser fan.