Winds of change

The promised wind farm work bonanza continues to generate excitement among offshore contractors keen to supplement today's patchy oil & gas orders.

Heerema Fabrication Group's Hartlepool yard in the UK landed a contract to fabricate and load out the topsides for two substation platform topsides for the Sheringham Shoal offshore wind farm from Areva T&D UK on behalf of owners Statoil and Statkraft. The 1000t decks, each 30.5m long, 17.7m and 16m high, are scheduled to sail out from Hartlepool in September 2010.

Sheringham Shoal, situated 17-23km north off the Norfolk coast and due onstream in late 2011, is owned jointly by Statoil (50%) and Statkraft (50%) through Scira Offshore Energy. Statoil is operator for the development phase and Scira will be the operator of the wind farm. Wood Group Engineering is the project manager.

JDR Cable Systems, which coincidentally opened a new manufacturing facility in Hartlepool last year (OE September 2009), secured a contract for the engineering, design and manufacture of over 200km of 33kV array cables for phase one of the London Array offshore wind farm being developed in the outer Thames Estuary by a consortium of Dong Energy, E.ON and Masdar. The development's 630MW first phase alone will see the installation of 175 wind turbines and two offshore substations in up to 23m of water, connected by subsea export cables to an onshore substation on the north Kent coast.

JDR's subsea power array cables, complete with proprietary hang-off and termination systems, will link individual wind turbine generators with wind turbine generator arrays and the offshore substations. The cables will be produced this year and next.

Another big London Array catch came Nexans' way. Its €100 million high voltage subsea power export cable contract involves the design, manufacture and supply of four 150kV XLPE submarine power cables to be laid in parallel, each 53-54km in length. Nexans' Halden factory in Norway will deliver two of the cables in 2011, and two in 2012, all in single continuous lengths. Another Norwegian facility, in Rognan, will manufacture the fibre optic elements to be incorporated in these HV cables.

Other mid-December awards for London Array included: Siemens Wind Power for the 3.6MW turbines, with 120m rotors and a hub height of 87m above sea level; the JV of Per Aarsleff and Bilfinger Berger for the foundations contract, supply of 177 monopiles and turbine installation; Future Energy, a JV between Fabricom, Iemants and Geosea, for the three-level offshore substations, and Visser & Smit Marine Contracting and Global Marine Systems for installation of the export and array cables.

During the recent Subsea Europe conference in London, Rhys Thomas, supply chain policy officer at the British Wind Energy Association, illustrated the scale of the opportunities in the offshore wind sector. The UK led the way on offshore wind capacity installed. However, the plans for future build, including the 25GW UK offshore Round 3, which received the go-ahead last summer, plus 6GW in Scottish territorial waters, dwarfed earlier developments.

Thomas estimated that 7600km of subsea cable (5200km HVDC and 2400km HVAC) would be required for Round 3 alone to connect offshore substations to shore. Further investment in the supply chain was required here, he said, as HVDC capacity was currently 1000km/yr. The figure for inter-array cables was 900km for round 3, involving a £1.3 billion spend.

Hailing offshore wind as a major business opportunity for the UK, Thomas said for 40GW around 8000 5MW turbines would be required. There would be service opportunities for harbours and ports, vessel operation and maintenance, on and offshore construction, storage, transport, training and divers. On the supply side there were requirements for monopiles and jackets, steel manufacture and fabrication, concrete, cables and transformers, bearings, castings, lubricants and ancillary items. He added that the Crown Estate was planning to hold 12 supply chain events dedicated to Round 3 around the UK this year (see 'Diary'). OE