Contractors will dig a pit to house a connecting block that will join Wave Hub’s offshore cable with onshore cables linked to a new electricity substation for the wave energy project.
The work, which is being carried out by Dawnus Construction and will take two weeks, will involve piling metal sheets into the sand to a depth of around 5 m to create a metal ‘box’ 10 m long and 5 m wide, with a further 5 m of sheet above beach level. The sand inside the box will then be excavated to a depth of about 3 m.
When Wave Hub’s 25 km, 1300-tonne subsea cable from JDR Cable Systems in Hartlepool is laid later this summer, it will terminate inside the beach pit and be connected to cables threaded through two ducts that have already been drilled through the sand dunes at Hayle.
These cables will lead back to a substation currently being built on the other side of the dunes, and ultimately connect Wave Hub with the National Grid.
Guy Lavender, Wave Hub general manager at the South West RDA, said: “Wave Hub’s grid connection is one of its major selling points to the global wave energy industry so this is a vital piece of work.
“Over the next two weeks beach users at Hayle are going to see various bits of plant and machinery at the top of the beach while the beach pit is constructed. Later this summer, once all the cables have been connected together in the pit, it will be filled in again and the sheet piling will be removed, so you’ll never know we were there.”
Wave Hub is creating a test site for wave energy technology by building a grid-connected socket on the seabed, 16 km off the coast of Cornwall, to which wave power devices can be connected and their performance evaluated.