To transmit energy without direct mechanical or electrical contact, a transmitter unit emits a laser beam onto a radiation receiver of a receiver unit including a photovoltaic cell arrangement surrounded by a ring-shaped reflector. A portion of the laser beam is reflected from the reflector back to the transmitter unit, where the received reflected signal is evaluated to determine the position of the laser beam impinging on the radiation receiver. The transmitter unit deflects the laser beam as necessary to impinge directly on the photovoltaic cell arrangement and track any relative motion of the receiver unit. The receiver unit orients the radiation receiver to optimize the energy reception. The position of the laser beam is modulated and the resulting variation of the reflected signal is evaluated to determine therefrom the position of the laser beam on the radiation receiver.