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An Innovative Solution for High Hub Heights

Bolted Steel Shell Tower

Higher towers significantly increase the energy yield of a wind turbine generator on sites with a high wind shear. At the same time, they pose considerable challenges in terms of transportability and costs. Siemens offers an in-novative and economically viable tower concept to allow its wind turbines reach heights above 100 m.

The Bolted Steel Shell Tower consists of multiple tower sec-tions, mounted on top of each other (Figure 1). Each section is made out of steel shells which are assembled together on site.

The steel shells are produced from bended steel plates and can be transported to site with standard trucks. They are bolt-

ed together with HRC (tension-controlled) bolts to form a tow-er section (Figure 2).

Depending on the hub height, the towers are constructed of 9 or more sections with a bottom diameter of 8 m or more.

The modular space concept of the Bolted Steel Shell Tower al-lows for very high hub heights (in excess of 140 m) with very low transportation requirements. The tower is erected in a short time and requires minimal maintenance. In fact, the HRC bolts require no re-torquing during the tower’s lifetime.

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siemens.com/wind

Published by and copyright © 2011:Siemens AGEnergy SectorFreyeslebenstrasse 191058 Erlangen, Germany

Siemens Wind PowerLindenplatz 2 20099 Hamburg, Germany

Customer Support CenterPhone: +49 180 524 70 00E-mail: support.energy@siemens.comAll rights reserved.

Wind Power DivisionOrder no. E50001-E310-A193-X-4A00

All rights reserved.

Subject to change without prior notice.The information in this document contains general descriptions of the technical options available, which may not apply in all cases. The required technical options should therefore be specified in the contract.

For more information, please contact

your Customer Support Center for your

local Siemens sales representative.

The tower includes a lift and ladder to reach the nacelle. A transformer unit can be installed within the tower. The door has standard dimensions to allow for the exchange of internal components. The tower can be fitted with aviation warning lights which can be bolted to the outside tower wall at any horizontal section connection.

The Bolted Steel Shell Tower features the following key benefits:

• Virtually no restriction on the maximum hub height, as long as a suitable crane is available

• Low steel requirement compared to tubular steel towers through the combination of larger tower diameters, high-strength steel and reduced material thickness

• The possibility to use steel coils which are cheaper than quarto steel plates

• An automated shell production process which ensures high quality and reduced costs

• Easy transportation of shells on standard trailers, in containers or by rail, facilitating access to even remote locations

• Fast and easy installation using tension-controlled HRC bolts and pre-installed internals (tower erection within a couple of days)

• No welded connections which reduces the risk of errors and long-term problems with fatigue and crack initiation

• Fully recyclable tower (material value is retained)• No service maintenance of bolt connections necessary• Effective corrosion protection, tower sealing and dehumidification

solutions

Product roadmap

• First prototype installed in May 2011 • Serial production in 2012

Figure 2. 3-D model and top-view of a tower section showing the steel shells

Figure 1. Bolted Steel Shell Tower with 9 sections

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