This review investigates different aspects of the realization of a North Sea offshore grid. The North Sea region has several characteristics that make large-scale integration of renewable energy sources attractive, such as large wind resources and huge hydro reservoirs in the North. A meshed offshore grid with underwater storage can contribute to facilitate sufficient flexibility in the system. The technical review reveals some aspects that need more research, particularly regarding the protection schemes. Furthermore, offshore storage solutions are under development. However, most other aspects are covered by readily available solutions. The greatest challenges seem to lie within standardization, cost-benefit sharing and harmonization of regulatory regimes of the surrounding countries. Nevertheless, several studies have shown highly promising economic benefits of establishing an offshore grid in the North Sea compared to traditional planning of point-to-point connections only.