Japan Agency for Marine-Earth Science and Technology (JAMSTEC) has been engaged in research and development of ocean-wave energy extraction technology for many years now. In particular, work began in 1987 an offshore floating type wave power device called "Mighty Whale". The open sea tests were started on the 10th of September 1998. Tests were conducted until March 2002. For converting renewable energy into electricity, it is not only important to raise energy conversion efficiency, but also to flat-and-smooth of generating electricity considering demand-and-supply balance and system cooperation. Although there are accumulation of electricity and a proposal of storing energy with a flywheel etc., as this measure, equipment different from power generation is needed, and it becomes the factor which raises cost. Generally, when it is fine, a wave is small, and when a wave is high, it is bad weather. For this reason, it is thought that photovoltaics and wave power generation can complement each other fault, and can perform flat-and-smoothization of the amount of power generation. This paper describes verification of the possibility of hybridizing of solar and wave energy and application to the system from an experiment of the combined cycle power generation system of the photovoltaics and wave power generation which were performed with the offshore wave power device "Mighty Whale"