Mechanical Technology January 2015

⎪ Power transmission, bearings, bushes and seals ⎪

WEG W22 generators power Windsor Castle

A project delivered by Southeast Power Engineering of the UK has seen a mini power station installed on the River Thames at Romney Weir to generate electricity using environmentally friendly water- driven Archimedes screw generators. The completed design features two WEG W22 Premium Efficiency IE3 gen- erators being driven by the screws via a gearbox to produce electricity, which now powers Windsor Castle. The WEG W22 units are ‘special’ products for this application in the sense that they are generators based on the WEG W22 motor. On starting the rotation of the Archimedes screws, the W22 draws electricity and is driven as a motor. Then, once turning at a suitable speed, the motor function changes over to that of a generator and the rotation of the screw is maintained by the water, which drives the W22 as a generator in order to produce electricity. The scheme is the brainchild of David Dechambeau, managing director of Southeast Power Engineering, who has overseen every step of the design and installation process. “In order to make this project sustainable, it was essential that we select the most ef- ficient equipment for the construction of this power station. The design called for a reliable generator with superior efficiency ratings and, on balance, the WEG W22 unit definitely fitted the crite- ria and it was straightforward to install.” The power station has been generat- ing electricity since July 2013 and is in the final stages of testing and commis- sioning. It comprises two Archimedes screws manufactured by Landustrie, each weighing 40 tonnes, connected to the WEG W22 IE3 class premium efficiency generators, which can deliver 320 kW at peak flow, exceeding the original design criteria. The WEG W22 IE3 generators were designed and manufactured in Portugal at WEG’s dedicated European Two s p e c i a l l y d e s i g n e d generators based on WEG W22 premium efficiency motors, are being driven by Archimedes screws to produce electricity for Windsor Castle in the UK.

Above: A mini power station installed on the River Thames at Romney Weir produces ‘green’ electricity by means of water-driven Archimedes screw genera- tors based on two WEG W22 premium efficiency IE3 generators. Right: The W22 units are ‘special’ products for this application in the sense that they are generators based on a W22 motor. At 96% efficiency, they were a critical part of the power transmission design to ensure the six-year return on investment target was met. manufacturing site. They are rated at 185 kW each and produce electricity at 400 V, which is then fed via a 500 kVA transformer to an underground line that connects to Windsor Castle and to the national grid. Efficiency was a key target for this application, as the installation has a fixed return on investment (ROI) period. At 96% efficiency, the WEG motor/ generators represented one of the best investments Southeast Power could make in the power transmission design to ensure their six-year ROI target was met. The installation has a minimum guaranteed design life of 50 years while Southeast Power has a 40-year tenancy of the site, which means that reliability and longevity were also very important considerations. If the screws stop turn- ing, there is a direct consequence in terms of revenue. “This was a very important project for us, not only because we are supplying the Royal Household, but also as an initial stepping stone for a number of

similar projects. It is essential that we install the most efficient and ecologically sound power plant possible. The work we are completing now will help to deliver future projects using similar tech- nology as demand for sustainable power increases,” Dechambeau concludes. WEG is represented in Africa by the Zest WEG Group, a leading supplier of electric motors, vibrator motors, vari- able speeds drives, softstarters, trans- formers MCCs, containerised substa- tions, diesel generator sets, switchgear and co-generation and energy solutions as well as electrical/instrumentation engineering and project management services. The Zest WEG Group operates a stra- tegically positioned network of support operations across Africa, which includes eight branches in South Africa and operations in Mozambique, Tanzania, Zambia and Ghana, with distributors in Botswana, Namibia, Zimbabwe, Zambia, Kenya, the DRC, Nigeria, Cameroon, Angola and Mauritania. q

Mechanical Technology — January 2015

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