Installation of the South West Regional Development Agency’s (SWRDA) pioneering Wave Hub marine energy project has begun today with the start of the cable laying operation.
Wave Hub is creating the world’s largest test site for wave energy technology by building a grid-connected socket on the seabed, 16km off the coast of Cornwall in South West England, to which wave power devices can be connected and their performance evaluated.
The £42M project has been developed by the SWRDA and is a cornerstone of its strategy to develop a world class marine energy industry in South West England.
Wave Hub will be connected to the shore via a 25km, 1300-tonne subsea cable that will be laid from the beach at Hayle, on the north Cornwall coast, out to the Wave Hub site by the cable laying ship Nordica.
The 33,000 volt cable has been manufactured in one continuous length and is made up of six copper cores, 48 fibre optic cables, two layers of steel wire armouring and an outer polymer sheath. It is 16cm in diameter.
The installation involves floating the end of the cable ashore from the Nordica, which will be stationed two kilometres offshore, and winching it to the top of the beach to a pre-constructed pit where it will be joined to onshore cables connected to a new electricity substation.
Once the cable is in place it will be buried on the beach to a depth of around two metres using a special machine that blasts a trench in the sand using high pressure water jets, burying the cable as it goes. The machine will continue offshore for a distance of two kilometres, and will be monitored by divers.
The cable operation at Hayle, which is being carried out by specialist contractor CTC Marine Projects, will take about two days. Once the cable is securely onshore the Nordica will head 16km out to sea to the Wave Hub site, laying the cable on the seabed as it goes. This will take around five days. The 12-tonne Wave Hub will then be lowered to the seabed in about 50m of water.
The Nordica will then head to the port of Falmouth on the south coast of Cornwall to pick up a 45-tonne underwater tractor that will bury the subsea cable for a further five kilometres offshore.
In the autumn Wave Hub will undergo a series of tests in preparation for welcoming its first wave energy devices next year.
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