Abstract: The hydroelectric power system according to the invention comprises at. least one wave generator, a wave booster and a wave energy, transformer. The at least .one wave generator comprises a water passage and is designed to transform at least some of the potential and/or kinetic energy of flowing water into waves. The wave booster is-designed to increase the amplitude of the waves at least in an area .where the waves are exploited. The wave' energy transformer is provided in. the area where the waves are exploited and comprises a derivable conversion element for converting at least part of the energy in the amplified waves into a different energy form. In the wave, booster, the wave energy in a first part of the water is utilized; to increase the amplitude of the waves in a second part of the water. This increase in the amplitude of the waves produces a higher potential energy and pressure in these waves than in the water, which was originally flowing.