On October 28, 2008, BARD Engineering GmbH inaugurated Germany’s first 5-megawatt (MW) near-shore wind turbine prototype in 2- to 8-meter deep water at Hooksiel off the German North Sea coast.
A boat trip took invited guests to the huge research turbine, which rises out of the water standing on top of a massive bright yellow coated Tripile foundation (see images below). The boat offered an impressive view on engineering details, the shear size of components and the large slow turning rotor.
The Hooksiel turbine is located close to the port of Wilhelmshaven and serves as Germany’s first open water wind installation that is fully exposed to the rough demanding North Sea marine environment. In addition to conducting a federal government supported offshore wind research program, BARD Engineering, the firm behind the impressive structure, plans to use this wind turbine for staff training purposes.
The near-shore project above all represents a major step forward towards BARD’s goal of becoming the world’s largest fully integrated offshore wind farm developer by the end of this decade. Founded in September 2003, family-owned BARD Engineering today employs some five hundred staff.
The company has already begun series production of itsBARD 5.0 wind turbine and next spring BARD will commence the construction ofBARD Offshore 1, its first 400-MW North Sea offshore wind farm that is expected to be operational by 2010. Offshore 1, an 80-turbine wind farm, will be located 100 km north of the isle Borkum in over 40-meter deep water.
Record-setting Development Schedule
The gear driven pitch-controlled variable speed BARD 5.0 offshore turbine was developed in a record one-year timeframe. With a top head mass of 425 tonnes, the turbine is a true heavy weight, and each of the nearly 60-meter long blades features a 28.5-tonne mass.
The BARD 5.0 wind turbine was designed by engineering consultancy aerodyn Energiesysteme of Germany, a company that among others also developed the patented 5-MW low-speed MULTIBRID M5000 offshore turbine between 1996 and 2003. Like the latter turbine series model, the BARD 5.0 features a single rotor bearing and a spherical cast iron main chassis. A major wind technology difference is that the BARD 5.0 features a state-of-the-art fast speed geared drive train, comprising a three-stage planetary & spur gear gearbox and a double-fed induction generator. All power electronics are located in the tower base.
The building and installation of the first BARD 5.0 land prototype took another year. Prototypes one and two were erected in late 2007 at windy Rysumer Nacken near the port of Emden. During their first 6 months of operation, the two land prototypes achieved 93% availability according to BARD CEO Heiko Ross (98 – 99% is considered state-of-the-art for serial products onshore).
In-house Production Line
BARD’s production line is in Emden, where turbine assembly and manufacturing of BARD 61 rotor blades takes place. Company headquarters and project development department are in Bremen. The patented Tripile foundations are being manufactured by the recently-founded BARD subsidiary, CSC Cuxhaven Steel Construction, based in the port of Cuxhaven.
The Hooksiel Tripile contains about 1100 tonnes of steel. Each Tripile comprises three individual tubular steel piles set apart and a transition piece. The piles are rammed into the seabed with the help of a special guiding frame. Next, they are joined together by the transition piece, which is placed on top, and which has, at its center, a connection flange for fitting the wind turbine tubular steel tower. The piles and transition piece are then permanently bonded by a grout connection.
Each BARD offshore project features identical Tripile, but the length of the piles varies with water depth.
BARD’s Hooksiel prototype was grid connected on October 25 thereby making it the company’s third wind turbine to become operational. At the commissioning, BARD CEO Heiko Ross gave a welcome speech and outlined some project highlights.
“Preparations commenced on August 28 with the first pile ramming. During the process we faced delay due to stormy weather, but the net time required for the entire installation process from pile ramming to turbine grid connection took only seven days. We are confident that it will be feasible to reduce this net installation period to five days once we gain experience with the offshore erection process. For this project we developed together with our partners NSW (General Cable) and Tekmar a cost-effective medium-voltage electricity transport cable solution for the inner park cabling which a patent has been applied for.”
Next Steps: More Than 5 MW?
With regard to BARD Offshore 1 progress, Ross said that he was confident that utilityE.oN Netz will have grid connection ready by September 2009. He also announced the placing of an order for a SWATH service vessel by German shipbuilder Abeking & Rasmussen. These innovative twin-hull vessels are known for their superior sea-faring capabilities under rough maritime conditions.
Ross also gave an impressive future outlook for the company, “From 2011 onwards it is our goal to install each year an 80-turbine offshore wind farm. Currently we are in the permitting process for seven other major projects in Germany and another three in the Netherlands,” he said.
Natalia Bekker, BARD Director explained the company’s potential plans to upgrade the 5.0. “The rotor diameter will remain unchanged at 122 meters. This upscaling is possible because the wind turbine contains substantial built-in design reserves and reaches nominal power already at 12.5 m/s. Measured average wind speeds in excess of 10 m/s in the North Sea section guarantee a substantial yield increase at a higher power output level. As a first step it is therefore a logical and cost-effective optimizing measure,” she said.
A Win-win Project
At the end of the Hooksiel inauguration ceremony, the German federal minister for the environment and nature conservation, Sigmar Gabriel, explained how the installation represented the country’s goals.
He started by praising BARD for its achievement, and symbolically handed over a check to Ross. The minister also emphasized Germany’s plans to have 10,000 MW offshore capacity operational by 2020 and 25,000-30,000 in 2030 and the enormous task ahead this represents.
Gabriel also specifically mentioned the new 70% higher feed-in tariff for German offshore wind projects that will come into effect January 1, 2009. The new rates as a policy instrument is aimed at creating a win-win situation for the environment and the people of Germany.
“It will serve as a contribution towards meeting environmental goals, boosting industrial development including job creation and reduce our dependency on fossil energy imports.”