The offshore wind project Arkona in the German Baltic Sea received the German Renewables Award in Hamburg. E.ON and Statoil's joint project got the Innovation of the Year award for a newly developed process that protects the steel foundations of offshore wind turbines from corrosion.
“The procedure developed by E.ON reduces the environmental impact and at the same time lowers the costs for the construction of offshore wind farms,” explained the independent jury from science and industry. The German Renewables Award is presented by the Clusteragentur Erneuerbare Energien, based in Hamburg.
During the 25-year operating life of an offshore wind farm, the metal-dissolving corrosion process is significantly reduced by the new process and emissions to the sea are reduced by several hundred tons. This progress is achieved by means of the thermal-spray aluminum process, whereby the mono steels, which are up to 81 meters long and weigh 1200 tons, are first coated with aluminum and then additionally protected with a synthetic resin layer. Arkona is the first project to install all monopiles of an offshore wind farm using environmentally friendly corrosion protection technology. This set new standards for the construction and operation of offshore wind power plants.
The award was submitted to E.ON project director Holger Matthiesen. “We have taken the risk of integrating innovation into our ongoing project process. We are pleased to have successfully implemented this jointly developed innovation in the Arkona offshore wind farm for the first time worldwide. This will further reduce costs for the offshore wind sector and further minimize the environmental impact,” said Holger Matthiesen at the award ceremony.
E.ON has developed the thermal spray aluminum process together with Rambøll, an engineering company. The companies EEW Special Pipe Constructions and Krebs then implemented the process industrially at their sites in Rostock. For this purpose, existing coating halls were expanded and the world's first fully automated coating line was developed.
In the coating process, a robot sprays molten aluminum onto the foundation using two arc burners. The process works under the highest occupational safety and environmental protection standards and is largely dust-free. The surface is then sealed with synthetic resin. The thermal spray aluminum process has so far been used primarily as corrosion protection for smaller steel components under water or for larger components above water, such as offshore substations.
For the foundations of the Arkona turbines, the process is being used for the first time on an industrial scale. Through automation, the alternative coating can lead to significant cost savings compared to conventional corrosion protection.
The Arkona project is located 35 kilometers northeast of the island of Rügen. The wind farm will have a capacity of 385 megawatts (MW) and will be able to supply up to 400,000 households with renewable energy from 2019 onwards. Compared to conventionally generated electricity, Arkona saves up to 1.2 million tons of CO2 per year. It will install 60 six-megawatt class turbines from Siemens. The plants are based on monopile foundations at water depths of 23 to 37 meters. Arkona is a joint venture between E.ON and the Norwegian energy company Statoil.