The German Association of Energy and Water Industries (BDEW) has published a study by Fraunhofer IWES examining scenarios for extending the lifetime and re-use of offshore wind farms and grid connection systems. The analysis was carried out with input from offshore wind farm and transmission system operators.
The permits for Germany’s first large offshore wind farms will begin to expire around 2040. Current rules require decommissioning after 25 years, even if continued operation could be technically, economically, and legally feasible. Many wind farms in the North Sea share grid connection systems with differing operating lifetimes, and future clusters are planned with 2 GW capacity. This creates challenges for coordination of decommissioning, repowering, and grid connection.
Fraunhofer IWES analysed different approaches, from uncoordinated decommissioning and rebuilding after 25 years to coordinated lifetime extension of up to 35 years followed by decommissioning and new construction. The study considered costs, downtime, failure rates, decommissioning and idle periods, as well as supply chain and vessel capacity.
The results show that coordinated lifetime extension can increase electricity generation while reducing overall costs compared with direct decommissioning and rebuilding after 25 years. It also places lower long-term demands on supply chains and reduces environmental impact.
BDEW recommends that the German government address the issue in the upcoming revision of the area development plan and in reforms of the WindSeeG and EnWG to establish regulatory conditions that would allow for coordinated continued operation of offshore wind farms and grid connections.
