NOVELTY - The device (1) has a Savonius type rotor with vertical axis carrying a rotary shaft (11) on which two reinforcement elements (5, 7) are fixed, where the reinforcement elements carry two flexible semi cylindrical blades (9). The shaft is arranged to vary in height from a folded position until a deployed position and vice-versa. Modification of height of the shaft causes modification of spacing between the reinforcement elements. The shaft is telescopic in a portion located between the reinforcement elements. The shaft has a jack configured to be actuated remotely.    USE - Savonius rotor type wind power device i.e. wind turbine, for mounting on a roof of a vehicle (all claimed) e.g. motor vehicle and camping cars, to convert wind energy into mechanical energy or electrical energy. Can also be used for Darrieus rotor type wind power device.    ADVANTAGE - The blades are inflatable and arranged such that the inflation modifies the spacing between the reinforcement elements from the deployed position to the folded up position in a remote and control manner, where height of the device in folded position is lower than the height of the device in deployed position, so that the device can be in deployed position when the vehicle is at a stop to reload battery, and the device is put in the folded position when the vehicle moves while facilitating simple retraction by reducing the obstructions in the device, and avoiding a human intervention for deployment or folding up of the blades on the device. The design of the device enables mounting the rotor on a telescopic mast and coupling the panels to increase or decrease the height to facilitate retraction and arrangement in a storage compartment located on the roof of the vehicle, so that the opening of the storage compartment and deployment or retraction of the device are controlled due to the dashboard of the vehicle.    DESCRIPTION OF DRAWING(S) - The drawing shows a perspective view of a wind power device on which the blade is represented in order to make appear the telescopic central rotary shaft.    Wind power device (1)    Reinforcement elements (5, 7)    Flexible semi cylindrical blades (9)    Rotary shaft (11)