NOVELTY - The method for obtaining electrical energy from the kinetic energy of water waves, comprises providing a device in water, where the device comprises electroactive polymer, which is arranged between electrodes and is arranged so that a part of the device is arranged above the water surface, and a mechanical energy is transferred from a variation of the water level to the electroactive polymer in the device, and expanding the electroactive polymer from a minimum expansion up to a maximum expansion as sequence of a mechanical effect of a water wave with an expansion speed and a wavelength.    USE - Method useful for obtaining electrical energy from kinetic energy of water waves.    ADVANTAGE - The method ensures simple and efficient obtaining of electrical energy from kinetic energy of water waves.    DETAILED DESCRIPTION - The method for obtaining electrical energy from the kinetic energy of water waves, comprises providing a device in water, where the device comprises electroactive polymer, which is arranged between electrodes and is arranged so that a part of the device is arranged above the water surface, and a mechanical energy is transferred from a variation of the water level to the electroactive polymer in the device, expanding the electroactive polymer from a minimum expansion up to a maximum expansion as sequence of a mechanical effect of a water wave with an expansion speed and a wavelength, relaxing the expanded electroactive polymer from the maximum expansion up to minimum expansion as sequence of reduced mechanical effect of the water wave, evaluating the maximum wave height of a water wave and correlating the maximum wave height with the maximum expansion over a assignment rule. The electroactive polymer is applied during a time interval of a time point up to a time point with an electric finish load and the electric breakthrough field of the electroactive polymer is not exceeded. The wavelength is determined in which a vertical acceleration of the water surface is measured by an acceleration sensor. The oscillation of the acceleration sensor-signal arises a wave length dependent voltage over a phase control loop, and/or the oscillation of the received acceleration sensor-signal is guided over a Fourier- or cosine transformation in the domain. The wavelength is determined in which the voltage applied between the electrodes at the electroactive polymer is measured. The oscillation of the voltage arises over the wave length dependent voltage over the phase control loop. The actual wave height is higher against the estimated wave height so that the penetration field strength of the electroactive polymer is exceeded from which loads are received. The device has a buoy, an axially segmented chain or liquid filled body from a material having electroactive polymer, or an arrangement of floating body connected together by a swivel joint, with an eccentrically arranged sections from a material having electroactive polymer, where the material expands and relaxes itself in a kink movement of the floating body opposing to each other. INDEPENDENT CLAIMS are included for:    (1) a system for obtaining electrical energy from the kinetic energy of water waves; and    (2) a computer program product.    DESCRIPTION OF DRAWING(S) - The diagram shows a graph of a wave progress with loading- and unloading flow of the electroactive polymer (Drawing includes non-English language text).    Water wave (100)    Loading- and unloading flow (110)    Reference sign (120)    Unloading interval (130)    Interval. (140)