Engineers working to install the South West RDA’s (Regional Development Agency) pioneering Wave Hub marine energy project have successfully brought the end of the subsea cable ashore at Hayle on the north coast of Cornwall.

The operation involved the use of more than 400 buoys to float a 1,800 metre stretch of cable weighing around 90 tonnes. The end of the cable was pulled to the top of the beach at around 5am on Monday (August 23), where it will be joined to onshore cables linked to a new electricity sub-station.

The operation had been delayed by technical issues when the cable lost buoyancy on two previous attempts. Cable laying contractor CTC Marine devised a different method, using a combination of pillow floats and A5 buoys.

The operation restarted on Sunday following modifications to the cable laying ship Nordica at the A&P Falmouth shipyard on the south coast of Cornwall.

Guy Lavender, the South West RDA’s Wave Hub general manager, said: “This was a critical milestone for Wave Hub and a great relief to see the cable brought safely ashore, but it’s just the first stage of the deployment operation. The next steps involve burying the cable on the beach and connecting it to the onshore cabling already in place, while the Nordica starts heading for the Wave Hub site offshore, laying the rest of the cable as she goes. All of that will take several days.”

The 20 megawatt Wave Hub is creating the world’s largest test site for wave energy technology by building a grid-connected socket on the seabed, 16 kilometres off the coast of Cornwall in South West England, to which wave power devices can be connected and their performance evaluated.

The £42 million project has been developed by the South West RDA and is a cornerstone of its strategy to develop a world class marine energy industry in South West England.

Wave Hub is connected to the shore via a 25km, 1,300-tonne subsea cable that can carry 33,000 volts. It 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 16 centimetres in diameter.

The cable is being 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. The machine will continue offshore for a distance of two kilometres. Thereafter a bigger trenching machine will take over for a further five kilometres and from there the cable will be held in place by rocks as the seabed it too hard to trench.

Once the cable has been laid offshore and the Nordica has reached the Wave Hub site, the 12-tonne hub will be lowered to the seabed in about 50 metres of water.

In the autumn Wave Hub will undergo a series of tests in preparation for welcoming its first wave energy devices next year.

Wave Hub is being funded with £12.5 million from the South West RDA, £20 million from the European Regional Development Fund Convergence Programme and £9.5 million from the UK government.