Siemens receives order to connect offshore wind farms via HVDC link

BorWin2, a consortium of Siemens Energy and Prysmian Powerlink, has received an order worth more than € 500 million from the German transmission grid company transpower. The consortium will connect the Veja Mate and Global Tech 1 offshore wind farms to the grid on behalf of transpower. The offshore wind farms, which will have a combined power generating capacity of as much as 800MW, will be connected to the grid via a submarine cable link carrying high-voltage direct current (HVDC). Siemens will supply the voltage sourced converter (VSC) system using Siemens HVDC Plus technology. The converter will be installed on an offshore platform, where the voltage level will be stepped up from 155 kilovolts (kV) to 300kV alternating current (AC) and then converted to direct current (DC) at the same voltage level. The platform will accommodate all the requisite electrical equipment for the HVDC converter. The Siemens Wind Power Offshore Substation (WIPOS) will be designed as a floating, self-lifting platform. This platform will be towed by tugs to its destination at sea, where the water is about 40 metres deep. The wind power will be transported via submarine and land cable to Diele near Papenburg, where an onshore substation will reconvert it from DC to AC for further transmission and distribution within the 400kV AC grid. The design and engineering phase for BorWin 2 will be completed by mid-2011. The onshore substation will be built in 2011, with installation of the offshore platform planned for mid-2012. Cable laying is scheduled for completion in 2012 as well. The whole transmission link is expected to begin operation in 2013.