"The high power yield of alpha ventus shows that offshore wind is already one of the pillars of a safe and reliable power supply. Offshore and onshore wind power complement each other perfectly, and even balance each other out", says Dr. Claus Burkhardt of the utility company EWE in his capacity as DOTI executive and overall project director of alpha ventus. After the technical problems of the first operating phase had been solved successfully, the wind turbines have reached a high availability. The turbines were operational for nearly 98% of the entire period. Claus Burkhardt: "This speaks for the reliability of German engineering in the wind energy industry. It also shows that our operations and maintenance concepts are fully validated."
On the other hand, Burkhardt points out that an offshore wind farm in Germany requires a considerably higher wind yield compared to its onshore counterpart in order to compensate for the significantly higher investment and operational costs. "This is a result of the difficult overall parameters here in Germany as opposed to other European countries, such as the required long distances from the coast and the correspondingly large water depths. They require elaborate offshore engineering for the turbines and foundations, as well as a corresponding infrastructure, such as suitable construction ships." According to Burkhardt, these factors continue to have a negative effect on the economic feasibility of German offshore wind farms and discourage potential investments. Thus, the German offshore wind industry first needs sufficient financial assistance to establish this young industry sector in Germany.
DOTI executive Rudolf Neuwirth of E.ON also underscores the great challenges the German offshore industry has to face in order to meet the ambitious goals set for offshore wind energy by the German Federal Government: "The successful alpha ventus pioneer venture shows the potential of offshore wind energy, but also the financial risks of complex offshore construction. Right now, as part of the massive changes in energy policy, the creation of no less than an entirely new industry is underway in the German North and Baltic Seas. Despite the positive experience of alpha ventus, many steps must still be taken", says Neuwirth. Nevertheless, alpha ventus’ positive interim results show that the German Federal Government is on the right path in focusing on offshore wind energy as an important element in establishing a CO2-friendly energy supply for the future of Germany. DOTI executive Bent Johansen of Vattenfall is pleased that the pioneer venture is bearing its first fruits: "alpha ventus’ positive performance confirms that we are on the right path in terms of our offshore commitments. Both the plants and their 'motor' – that is, the wind – have proven to be reliable. With alpha ventus, we are making an important contribution to the development of climate-friendly energy production. Furthermore, in the rough conditions of the North Sea we are gaining valuable technical experience for the ongoing development of the entire German offshore industry. With the follow-up offshore projects by our three utility companies in the German North and Baltic Seas, we will further widen our expertise.”
Research and development results will be incorporated into the design, construction and operation of future offshore turbines. EWE, E.ON and Vattenfall established the "Deutsche Offshore-Testfeld und Infrastruktur GmbH & Co. KG” (DOTI) in order to realise the alpha ventus wind farm. Using the name "Borkum West", DOTI leased the licensing rights for the test field from the Stiftung der Deutschen Wirtschaft für die Nutzung und Erforschung der Windenergie auf See (Foundation of the German Industry for the Utilisation and Investigation of Wind Energy at Sea.
alpha ventus is the first German offshore wind farm that was constructed on the high seas. The pilot project is located some 45 kilometres from the coast of Borkum and provides fundamental experience in the construction and operation of an offshore wind farm. Twelve 5- megawatt class wind power turbines are operating at the alpha ventus test field: six AREVA Wind M5000 turbines and six REpower 5M turbines, resting on two different foundations. Whereas the AREVA wind turbines stand on tripods, the REpower turbines are mounted on jacket foundations in a water depth of 30 metres.