Like all of Valcrow's work this wind turbine model is designed to be printed in parts and snapped together without any adhesives or external fasteners. The model is of the Vertical Axis Wind Turbine type, or VAWT's as they are known by engineers. They're modern windmill designs that arrange the generator and gearbox close to the ground, making it easier for the turbine to be serviced and repaired. Because they are set up in a vertical direction the turbines can function in any direction and do not need wind-sensing and orientation mechanisms.
Check out this timelapse of Valcrow's VAWT model being printed and assembled: