A wave power assembly having a hull and a linear electric generator. The rotor is connected to the hull by connection means so that lifting force is transferred from the hull to the rotor. Spring means exert a force on the rotor that is counter-directed the lifting force. The spring means is arranged to, at a motion amplitude corresponding to 50% of the maximum length of stroke of the rotor, exert a force, the size of which varies by a factor of 2.5 as a maximum. The invention also relates to a wave power plant built up from wave power assemblies according to the invention. Furthermore, the invention relates to a use of the wave power assembly and a method for the generation of electric energy.