02.09.2015 - The offshore wind farm Global Tech I (GTI), located in the North Sea 140 kilometres off the German coastline, officially went into operation today. With a capacity of 400 megawatts, it is the largest offshore wind farm to go on grid this year in Germany. Axpo has a 24.1% share in this wind farm, making GTI the first offshore farm with substantial Swiss participation. Axpo will market the energy produced off the North Sea coast directly through its subsidiary in Germany in proportion with its own holdings.
With the inauguration of Global Tech I, Axpo can selectively and steadily expand its position and know-how in the wind power business. „Global Tech I is an excellent fit in the Axpo strategy,“ says Andy Heiz, Head of Assets at Axpo. The inauguration is a „milestone and an important expansion of our wind energy portfolio.“ Along with the acquisition of the wind farm developer „Volkswind“ announced on 16 July 2015 and the interests in onshore wind farms, GTI counts among the investments Axpo has made to boost added value from renewable energies in Europe. In Switzerland, Axpo is already by far the largest producer of renewable energy.
With 80 5-megawatt wind turbines and a total capacity of 400 megawatts, GTI is the largest offshore wind farm to go on grid this year. In purely mathematically terms, the plant can supply some 445,000 households with electricity. The North Sea power plant GTI makes an important contribution to eco-friendly energy supply and the achievement of climate goals. In comparison to conventional coal-fired power plants, CO2 emissions can be reduced by 1.2 million tons per year.
The Global Tech I wind farm covers an area of over 40 square kilometres, corresponding to the surface area of the city of Saint Gall. Located 140 kilometres from the logistic base in Emden, it is also the wind farm that is the farthest away from the coast. The total investment costs for the offshore wind farm amounted to 1.8 billion euros. Alongside the German energy companies Stadtwerke München and ENTEGA AG, Axpo is the third largest shareholder of GTI.
Construction of the wind farm in itself is an engineering feat: The wind turbines were mounted on steel tripod foundations 40 metres under water while taking into account strict marine environmental protection requirements. The overall logistics for every construction phase from foundation installation to the assembly of the rotor stars had to be optimally and flexibly coordinated taking into account factors such as weather, the availability of ships, crews, material, as well as grid connection. Since grid connection was postponed several times, Global Tech I adapted the construction schedule as best possible and realised the project on budget and on schedule despite the delays.
In order to ensure smooth operation of the wind farm, the offshore substation platform manned with 37 people and the operation control centre in Hamburg’s HafenCity work closely together. The control centre monitors sea activity and all the wind farm parameters. This also includes monitoring the internal cable network and large transformers used to convert the electricity generated by the wind turbines from 33 to 155 kilovolts. It’s all done by mouse click in the heart of Hamburg.
The operation control centre is also responsible for communication with the direct marketers of the generated electricity, as well as the interim grid operator. Due to the wind farm’s remoteness, the substation is set up as a logistical base for service and maintenance. Similar to a small, self-sufficient town, the centre is equipped with essential infrastructure such as fresh and wastewater treatment, a hotel, a hospital with paramedics and telemedical equipment, as well as its own fire brigade and helicopter-landing pad with filling station.