Optimal generation and transmission development of the North Sea region: Impact of grid architecture and planning horizon

Abstract — The European Union is pushing to achieve a sustainable, competitive and secure energy supply in Europe. This has translated into significant long-term renewable energy targets towards 2050, and the ambition to improve the European grid. A large share of this development is expected to occur in the North Sea. This paper investigates which transmission architecture is the most beneficial to integrate large shares of renewable energy in the North Sea region, and the consequences of the planning horizon when planning such a system towards 2050 are analysed. This is achieved by performing investment optimisation of generation and transmission for different scenarios. It is found that: 1) an integrated offshore grid configuration planned over a long planning horizon leads to cost minimization; 2) the grid topology is not likely to influence the penetration of variable renewable energy, but it will affect the contribution of each variable renewable energy type and the system costs; and 3) not taking the future into account when developing the energy system is likely to lead to a more expensive system. These results remark the importance of long-term planning horizon for energy systems and grid expansion and calls for a political focus on planning and international cooperation.