Abstract
Large amounts of offshore wind (OW) power are expected to be installed in the North Sea in the next decades with countries aiming for a total of 300 GW by 2050 as stated in the Ostend declaration. This scale-up will help achieve the decarbonization of the European energy system. However, it is unclear how the introduction of such large volumes of OW will impact the power system, the energy system and the profitability of the OW developments. This paper investigates these issues. A capacity expansion planning model of the European energy system is used to compare cases with limited OW investments, free investments and investments in OW fixed to the targets for 2040. It finds that large amounts of OW mainly reduce the installation of onshore wind, PV and nuclear while causing a total system cost increase across the horizon of about 1%. The offshore grid layout has little impact on the return on investment (ROI), with slightly higher ROIs for meshed offshore grids. Meeting the OW targets increase their ROI by forcing investments to be made at an earlier date, allowing production in periods with higher electricity prices.
