The German Association of Energy and Water Industries (BDEW) today published a study on the further operation and reuse of offshore wind farms and grid connection systems. The report was commissioned by BDEW and prepared by the Fraunhofer Institute for Wind Energy Systems IWES in cooperation with offshore wind farm operators and transmission system operators. It analyzes options for the further operation and reuse of these farms.

The operating permits for the first large offshore wind farms in Germany will expire around 2040. Without additional regulations, the installations would have to be dismantled after 25 years of operation, even if their continued operation were technically, economically, and legally possible (according to the BDEW 2024 white paper). This situation raises concerns from a sustainability perspective, including the impact on the marine ecosystem. In terms of cost-effectiveness and feasibility, the transition to subsequent wind farms is particularly difficult because in existing clusters in the North Sea, multiple farms with different operating periods are often connected to a common grid connection system. In addition, existing farms are to be combined into larger areas with 2 GW connections in the future, which requires coordination in terms of operating periods, dismantling, and construction.

Therefore, the Fraunhofer IWES study analyzed various scenarios for further operation and reuse, ranging from direct, uncoordinated dismantling and construction to coordinated forms of further operation followed by dismantling and construction. The study covered factors such as operating and investment costs, failure rates, dismantling and downtime, and the availability of ships and supply chains.

The results of the study show that coordinated extension of the operation of installations to 35 years, followed by dismantling and construction of new ones, can increase electricity production in the cluster while reducing overall costs to the economy compared to a scenario where farms are directly dismantled and replaced after 25 years. Furthermore, scenarios with coordinated extension of operation place moderate demands on supply chains and lead to less burden on the ecosystem in the long term.

“The study shows that coordinated life extension of offshore wind farms and grid connection systems can bring significant benefits in terms of cost efficiency and environmental balance in the development of offshore wind energy,” says Kerstin Andreae, CEO of BDEW. “It is crucial that operators receive planning certainty as early as possible so that they can adapt their operating and maintenance strategies accordingly and address the increasing susceptibility to failure as the installations age. The earlier further operation can be prepared, the more efficiently it can be enabled.”

“The federal government should therefore address this issue in the next update of the offshore development plan and create an appropriate regulatory framework as part of the planned reforms of the Offshore Wind Energy Act (WindSeeG) and the Energy Industry Act (EnWG). This includes an adapted compensation system for offshore wind energy, as well as appropriate provisions regulating the possibility of further operation of offshore connection systems belonging to transmission system operators.”

The results of the study can be found here.

Source: BDEW