Development of an economical and insured TLP substructure for a 6MW wind turbine - Use of steel reinforced concrete composite material

Jochen Grossmann1, Frank Adam 2 ,1, Uwe Ritschel2, Frank Dahlhaus3, Karsten Koepke4
1GICON Holding GmbH, Dresden, Saxony, Germany, 2University of Rostock, Rostock, Mecklenburg-Hither Pomerania, Germany, 3TU Bergakademie Freiberg, Freiberg, Saxony, Germany, 4ESG GmbH, Stralsund, Mecklenburg-Hither Pomerania, Germany


Offshore wind parks will play an important role in supplying the increasing energy demand while considering ecological and economic aspects. Especially floating foundations which have a great potential for offshore wind farms in water depths between 40 m up to 200 m and more, will be a major factor. In cooperation with the University of Rostock and the University of Freiberg, GICON has developed a special solution of a floating foundation, referred to as GICONŽ-TLP. It is an improved version of a TLP. This solution has been optimized and tested over several years to reach a development stage as an economic and ecological substructure for offshore wind turbines of the third generation (6 MW capacity and higher).


The objective of this presentation is to focus on the design of a substructure incl. the anchoring in the seabed by considering the dynamics of a 6 MW wind turbine. The pre-design for a 6 MW sub-structure incl. the anchor pre-design will be presented. One main focus will be on the supply chain and the cost saving potential based on both an optimized design and an optimized supply chain.

In addition, the anchoring via a gravity anchor will be another focus of the paper and presentation. For the GICONŽ-TLP, several anchor-concepts can be used to meet specific seabed-conditions.



The key aspect will be the bankability confirmation by a German Bank, as well as the confirmed insurance coverage provided by ALLIANZ. The bankability confirmation is based on a LCOE calculation at LCOE < 9.0 €ct/kWh for the GICONŽ-TLP in 2025. The LCOE calculation parameters used by an independent entity were for a wind farm with 80 units in 40m water depth and 50km from shore. The costs include all relevant costs such as CAPEX, OPEX, decommissioning and transformer platform costs etc. This TLP has obtained insurance coverage for a 2.3MW demonstrator in the German Baltic Sea and for the serial design of the 6MW substructure (includes coverage for operating failure). This is a unique accomplishment for all current and future TLP generations.


The presentation will highlight the utilized material to fabricate the substructure. This steel reinforced ultra-high performance concrete is one core technology to reduce the costs as well as to optimize the manufacturing process. Therefore, the optimized substructure, respectively the process of optimization by using lightweight components will be presented.


Based on the results GICON developed a cost effective TLP substructure for the next generation of offshore wind turbines. The most imported fact was to maximise the modularity to get a higher flexibility within the supply chain.