European renewable energy leader RWE has celebrated an innovative foundation technology at RWE’s Kaskasi offshore wind farm. Special collars were installed around the monopile foundation at seabed level for the first time ever in the renewables industry. The ‘collared monopile’ is a design based on a RWE patent. The new technology provides additional support for lateral loading, increase the bearing capacity and improves the structural integrity of the entire foundation. Installation works were carried out by DEME Offshore.Kaskasi is RWE’s sixth wind farm off the German coast. 342 MW project is currently under construction 35 kilometres north of the Island of Heligoland. In total three innovative foundation collars were successfully embedded into the seabed, each 7 metres high weighing 170 tonnes. The installation in water depths of up to 25 metres was carried out by the jack-up vessel Sea Challenger from DEME Offshore. The space between collar and monopile foundation was filled with grout material, creating finally a stable connection. RWE will carry out accompanying tests to verify that the collar improves the structural behaviour in comparison with standard monopiles.The detailed design of the collars was developed by the German civil engineering company JBO based on the RWE patent, Bladt Industries was selected as manufacturer and DEME Offshore was responsible for the transportation and installation.