A method of operating a wind turbine system includes: determining, by an industrial process controller, if an actual wind speed value, received from an anemometer, of a wind at a location of the wind turbine system is less than a predetermined minimum wind speed value. If so, then calculating a command speed value that will cause a variable-speed drive to drive the motor/generator and a sail assembly at a speed that the sail assembly would turn if the actual wind speed value was the minimum wind speed value, such that the sail assembly turns and provides a visual effect. If not, then calculating a command speed value based on the actual wind speed value such that the variable-speed drive and the motor/generator will operate in a braking mode to recover a braking energy of a load of the wind on the sail assembly.