Siemens goes with the tidal flow

Siemens last month increased its stake in UK tidal energy company Marine Current Turbines to 45%, with Michael Axmann, CFO of Siemens Energy's newly established solar & hydro division, declaring: ‘We will actively shape the commercialization process of innovative marine current power plants.'

Driven by global CO2 reduction commitments, double-digit growth rates are being forecast for the ocean power market until 2020, with some estimates suggesting the global potential for power generation using tidal power plants could be 800 terrawatt-hours (TWh) per annum. Siemens entered this market last year by acquiring a minor stake in Marine Current Turbines, the acknowledged pioneer of horizontal axis marine current turbines (OE August 2010).

MCT chief executive Dr Andrew Tyler says: ‘Through the expansion of the partnership with Siemens, we have further strengthened our position in the tidal energy market. We have the increased backing of a major industrial player which is essential to support the commercialization of our proven technology. We are about to approach investors to secure funding for our first two tidal array projects, and Siemens' increased investment as well as UK Government support should give investors the confidence that we have the necessary backing to deliver these crucial projects and the ones to follow.'

MCT will shortly be presenting two project investment prospectuses to the market for its 8MW Kyle Rhea project in Scotland and its 10MW Anglesey Skerries project in Wales. For both projects, applications for leases from The Crown Estate have already been approved. Further encouragement for these initiatives came in the UK government's 20 October Renewable Obligation Certificate (ROC) banding review, which proposes trimming onshore and offshore wind farm subsidies slightly, to 0.9 and 1.9 ROCs per megawatt hour respectively, while raising support for tidal stream and wave technologies to 5 ROCs/ MWh up to a 30MW project cap (2 ROCs/MWh above that cap).

In addition, MCT is planning to deploy a tidal system into the Force facility in Canada's Bay of Fundy and has an approval for a lease from The Crown Estate to deploy a 100MW tidal farm off Brough Ness, on the southernmost tip of the Orkney Islands in Scotland.

MCT has already successfully implemented its first commercial scale demonstrator project SeaGen (pictured) in Northern Ireland's Strangford Lough. Since November 2008, SeaGen's two axial turbines, with a combined capacity of 1.2MW, have been feeding power into the grid to supply the equivalent of around 1500 homes. SeaGen has to date generated over 2.7GWh of electricity to the grid, hailed as the largest amount of electricity in the whole of the ocean power sector. OE

BOLT TIGHTENING: Training programme provider Oilennium has entered the wind energy sector with its new online wind turbine bolt tensioning simulator, said to offer a complete overview of the bolting process. Orbis Energy and EEDA awarded a grant to Oilennium to develop the system's associated courses. Oilennium in turn sought the specialist help of Hydratight. Developed under the guidance of Rob Humphreys, key account manager with Hydratight, the simulator takes the user from checking that the correct equipment is available and in good order, assembling the bolt tensioning equipment on to the application fasteners and correctly configured, operating the equipment, and ensuring that the correct tension has been applied to bolts inside the hub.

Thinking big at Bréhat: French utility EDF rates its €40 million Paimpol-Bréhat development, due onstream next year in 35m of water off France's west coast, as the world's largest tidal energy array. It will feature four 2MW OpenHydro turbines off the island of Bréhat and is expected to power 4000 homes. The 16m diameter open-centre turbines, built by Brest's DCNS shipyard, each weigh 850t and stand 22m high on the seabed once mated to their foundation bases.

Testing times for Virginia
Fugro has been contracted by Poseidon Atlantic to provide development and engineering services for a proposed commercial wind turbine certification test center in the US on the eastern shore of Virginia.

The initial phase of the Poseidon Atlantic project is to be located along the Atlantic coast in Northampton County, Virginia where a recently adopted ordinance allows test wind turbines with tip heights up to 228m. The project partners – Real NewEnergy in collaboration with Fugro and Ecofys, with the backing of the Commonwealth of Virginia, the Virginia Port Authority and the Royal Netherlands Embassy – believe the facility will provide ‘a unique opportunity and location for certification testing of offshore-scale and large land wind turbines' and anticipate that it will be ‘the first facility where wind turbine generators proposed for offshore deployment can be erected and certified in the US'.

DanTysk cable contract
Dutch offshore contractor Van Oord has awarded Parker Hannifin's Energy Products Division (EPD) a contract for the production and supply of 111km of infield cables, accessories and offshore services for the DanTysk offshore wind farm project, located approximately 70km west of the German North Sea island of Sylt.

DanTysk is a joint venture between Vattenfall Europe Windkraft and StadtwerkeMünchen and Vattenfall is responsible for its construction and operation. The 80 turbines have a total capacity of 288MW.

Parker EPD's contract with Van Oord encompasses design, production and delivery as well as connection consulting during the installation of the cables to the 80 steel foundations. Cable production will begin at EPD's Tønsberg manufacturing plant in Norway next year, with delivery slated for the spring of 2013. The cable lengths will be delivered in four shipments. 
 

Bearing up Installation of elastometric spring bearings designed to improve the vertical load carrying capacity of Sheringham Shoal's offshore wind turbines was completed by Trelleborg Offshore Norway on each of the UK wind farm's 90 foundations before the onset of winter. Trelleborg worked with project team members from owner Scira Offshore Energy and operator Statoil to design, manufacture and deliver the bearings – 552 of them in all – following reports of grouting failures on other wind farms. The bespoke steel and rubber bearings were designed to reduce the vertical load on the grouted connection between the inner monopile pipe and the outer transition piece, which together make up the foundation on which the wind turbine will sit. Each of the wind farm's monopiles are between 44m and 61m long, have a 4.2-5.2m diameter, weigh from 375-530t and have been piled between 23m and 37m into the seabed. The bright-yellow transition pieces were fitted over the top of the monopiles and secured with the cement grouting, in preparation for the installation of the turbines. The grouting filling the gap between the monopile and the slightly larger diameter transition piece has to withstand both the vertical weight of the tower and the lateral force of the wind. Sigmund Lunde, Statoil's company representative for the bearings contract, says examples of failing grout connections elsewhere had led certification authority DNV to reduce acceptable loads which could be placed on grouted connections required by offshore wind farms.