“It’s great to see the building gradually filling with life. That is our reward for the not exactly stress-free construction time,” explains Peggy Kleidon, the project engineer responsible at RWE Innogy. “Together with our local partners, we have built a modern and above all functional building in the shortest of times – and that exclusively with sustainable materials. Because we intend to crown our new building with certification by the German Sustainable Building Council. With that we are pursuing a logical overall concept for the holiday island of Heligoland, where renewable energy production and sustainable building go hand in hand.”
The building comprises a floor area of around 1,200 square metres. Storage spaces and a workshop are situated on about half of the floor area. The other half of the two-storey building houses changing and sanitary rooms, as well as offices, rest and meeting rooms and a control room to manage the wind farm. Containers and larger components can in the future be stored temporarily on the outdoor area.
“Unlike on land, wind turbines at sea cannot be serviced and repaired at any time of day or night. Waves, wind and weather place quite new demands on our service engineers, so short routes, local partners and good downstream service logistics are essential for viable operation of power plants like these,” explains Nils Feil, head of the new RWE service station. “With Heilgoland we have found a safe haven and are looking forward to operating our Nordsee Ost wind farm from here for at least the next 20 years.”
Heligoland’s southern harbour
The maintenance workload for wind turbine at sea is higher than for wind turbines on land, because the loads through waves and saltwater are much higher. As standard, a wind turbine at sea will be serviced on about four to five days a year. Unforeseen events, such as fierce storms, can make further maintenance work necessary. For the operating base on Heligoland that means ships with service personnel must regularly set out for the wind farm at sea and return again in the evening when the work has been completed. These ships are fuelled and loaded with tooling and spare parts from the quayside.
Upon its completion in the spring of 2015, the Nordsee Ost offshore wind farm will have an installed power of around 295 megawatts and supply the equivalent of 300,000 households with electricity. At the moment, the 48 wind turbines of the 6-megawatt class are being erected at the site. From this summer onwards, the first maintenance work will be carried out on the foundations in parallel. The focus is on the stability of the foundations and safe accessibility. The inspections will be performed both above and under water: besides visual inspections of the structures and corrosion protection, part of the work above the water will be inspections of the welt and bolt joints by inspectors specially trained for climbing and working at heights. Special submersibles will be used for the underwater inspections.
RWE apartment building
The service personnel responsible for maintenance will be accommodated on Heligoland. RWE Innogy has had an apartment building built on the island for that purpose and rented it completely. With around 320 square metres, the building is equipped with 18 apartments and a big lounge. Senvion has rented a second building with twelve apartments for its employees, so there has been accommodation available since the beginning of 2014 for around 30 offshore employees of RWE Innogy and Senvion.