Substations for offshore wind farms: a review from the perspective of the needs of the Polish wind energy sector

Offshore renewable energy, and in particular the offshore wind energy sector, is still developing in many countries around the world. Wind offshore projects are characterized by the need to build offshore electric power transmission infrastructure. Offshore substations are a key element of submarine electric power transmission systems. Due to the environmental conditions, an offshore substation is constructed as an indoor facility located on a platform. Depending on the offshore wind farm capacity, there are various solutions for platform and substructure designs used for the substation. Numerous economic and technical analyses indicate a significant potential for the development of offshore wind energy in Poland. By 2030, this potential is set at 6 GW of installed capacity, taking into account 2.2 GW of power included in the connection agreements being concluded. The main objective of this paper is to present the prospects for the development of offshore wind energy in Poland, and to describe the various offshore substation solutions and the different aspects of substation operation. Offshore wind energy resources and power capacity are also presented. Moreover, solutions for offshore substation platforms, electrical equipment and layout, functions of offshore substations in the power systems and offshore substation designs are described.