Abstract: The energy converter includes a frame, a rotor mounted in the frame with a rotor shaft and vanes, and an element that can connect the rotor shaft to a generator, an alternator or another energy-converting mechanism. Each vane has a holder, a plurality of blades which hinge in the holder about small axes which lie in parallel relationship with the rotor shaft, and stops for the blades. The blades are a plurality of leaves which hinge on one another about axes which lie in parallel relationship with the rotor shaft. Stops limit the relative hinging motion of the leaves on the one hand to the position where they lie in extension of one another, and on the other hand to a position where the leaves form angles, for example in the range of 135.degree..