Löwenstedt Community Wind Farm Banks on Radio Shielding Wind Turbines from Siemens


• Siemens direct-drive wind turbines are the only product that meets the site's stringent regulations

• Protection against electromagnetic emissions allows erection directly beside a receiving station of Deutsche Flugsicherung (DFS)

• Community wind farm counts over 280 shareholders



The receiving stations of Deutsche Flugsicherung (DFS), the company in charge of air traffic control for Germany, are an important part of the wireless communication infrastructure of the aviation industry. One of these radio navigation stations, close to the village of Löwenstedt in Germany's northern state of Schleswig-Holstein, supports communications of pilots aloft. At first, it did not appear feasible for a publicly-owned wind project to be erected close to this receiving station: To gain approval the wind turbines need to comply with highly stringent radio shielding requirements. Then, however, the farm planners opted for Siemens Model SWT-3.0- 113 wind turbines - direct-drive units that are the only wind turbines offering the required protection against electromagnetic emissions. Their remote-control capability also ensures that these Siemens' wind turbines comply with the technical requirements governing the nearby radar installations operated by the Bundeswehr - the Federal Defense Forces of Germany.



Siemens is set to deliver five Model SWT-3.0-113 units to the operator, Bürgerwindpark Löwenstedt GmbH Co. KG. These units offer extremely low electromagnetic emissions of the permanent magnet generator and the electrical systems. Because these units feature a closed cylindrical ring of conductive permanent magnets that rotate around the stator with the generator windings, the electrical energy does not have to be derived from moving components by e.g. sliprings. Added to this is the shielded design of the generator's power electronics and other electrical components which are encapsulated in a metal housing as well as within the structure of the nacelle and the steel of the tower. Due to the position of the power converter in the bottom of the tower the range of electromagnetic emissions is very limited. Faced with the stringent regulations, the offer from Siemens was the only solution developers WEB Andresen in the town Breklum and the engineers of Ingenieurbüro Henning Holst in nearby Husum would consider. The co-managing directors of the publicly-operated wind farm, Jan Peter Thoröe and Astrid Jensen, recognized that this solution offered the best chances for building the wind farm at this sensitive location. Siemens' Wind Power and Renewables Division submitted verifying proof of the turbines' electromagnetic compatibility by measurement in the relevant frequency ranges, and the project was granted the required permit. All five Siemens wind turbines will be erected within a radius of two kilometers around the DFS receiver station.



"The conflicting interests of air traffic control and publicly-operated wind farms have presented problems for a number of wind power projects in the state of SchleswigHolstein," confirms Jan Peter Thoröe, chief technical officer of Bürgerwindpark Löwenstedt GmbH Co. KG. "In Löwenstedt, Siemens' advanced technology helps us comply with the regulations dictated by Deutsche Flugsicherung and the Bundeswehr, and simultaneously implement an important project in which more than 280 local citizens are stakeholders."



"The design concept of our direct-drive D3-series wind turbines offers numerous advantages," confirms Thomas Richterich, CEO of the Onshore Markets unit of Siemens Wind Power and Renewables Division. "For the Löwenstedt project, we are especially pleased that the unique electromagnetic compatibility of these units has contributed to ensuring project feasibility at this location."



Shielded and electromagnetically nonhazardous:

Siemens' Model SWT-3.0-113 wind turbine generates electricity in a permanent magnet generator arranged between hub and nacelle (transparent section shown above). Because the stator with the windings does not move during operation, while the cylinder-shaped rotor with its ring of permanent magnets rotates around it, the electromagnetic field remains inside the unit. Electrical systems such as the power electronics are encapsulated inside the unit as well.



For further information on Siemens' Wind Power and Renewables Division, please see: www.siemens.com/wind



Siemens AG (Berlin and Munich) is a global technology powerhouse that has stood for engineering excellence, innovation, quality, reliability and internationality for more than 165 years. The company is active in more than 200 countries, focusing on the areas of electrification, automation and digitalization. One of the world’s largest producers of energy-efficient, resource-saving technologies, Siemens is No. 1 in offshore wind turbine construction, a leading supplier of combined cycle turbines for power generation, a major provider of power transmission solutions and a pioneer in infrastructure solutions as well as automation, drive and software solutions for industry. The company is also a leading provider of medical imaging equipment – such as computed tomography and magnetic resonance imaging systems – and a leader in laboratory diagnostics as well as clinical IT. In fiscal 2014, which ended on September 30, 2014, Siemens generated revenue from continuing operations of €71.9 billion and net income of €5.5 billion. At the end of September 2014, the company had around 343,000 employees worldwide. Further information is available on the Internet at www.siemens.com.



Siemens AG

Communications and Government Affairs

Head: Stephan Heimbach



Wittelsbacherplatz 2

80333 Munich

Germany



Contact for journalists:

Bernd Eilitz

Phone: +49 40 2889-8842; e-mail: bernd.eilitz@siemens.com

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