With the great use of non-renewable energy sources, and the constant increase in pollution of the Earth, man turned to exploitation of renewable energy sources. As there is a possibility of wind in every part of the Earth, wind is seen as a very available source of energy. Wind energy has been known to man since ancient times, and was initially used for the purpose of obtaining mechanical energy. With the development of technology and the appearance of electricity, the primary purpose of exploitation wind energy is to obtain electricity through wind turbines. In the beginning, wind generators were installed exclusively on land, but with the additional development of technology and the development of larger wind generator, it was possible to efficiently use this type of energy at sea. In this paper, the subject of research is wind energy as a renewable energy source with a focus on presenting II the development of wind energy at sea. Except wind energy, sea energy sources are also presented. The part related to the specifics of the use of wind energy at sea, and special ships used for this purpose, has been specially treated. An analysis of the current development of wind energy in the world, Europe and Republic of Croatia has been made. For the Republic of Croatia, an analysis of suitable areas of the Adriatic sea for the use of wind energy and the construction of wind generators is being carried out.