ETI project to reduce subsea cable costs for wave and tidal power

The 18 month project, costing £1.1 million and led by MacArtney, a global supplier of underwater technology, will develop an 11 kV wet-mate connector, which will be tested and demonstrated under workshop and real-sea conditions.

The connectors enable two power cables to be linked together. Currently, marine device developers either use dry-mate connectors, which have to be lifted out of the water and connected on a barge, or they use a 6.6 kV wet-mate connector which is not a high enough voltage rating for efficient transmission of maximum outputs from wave and tidal devices back to shore.

The use of these higher voltage wet-mate connectors in future wave and tidal power arrays is expected to lead to considerably lower installation, operating and maintenance costs, and more rapid deployment of marine energy arrays, the ETI says.

They will enable the use of remotely operated vehicles to perform electrical connections on the sea-bed instead of having to deploy barges to perform these connections above the surface.

The increase in voltage rating to 11 kV could significantly reduce the capital costs associated with offshore energy installations since higher voltage connectors allow more power to be transmitted per cable.

ETI Chief Executive Dr David Clarke, says: “Developing wet-mate connectors with a significantly higher kV rating will considerably reduce the cost of tidal and energy arrays by cutting the cable costs to shore and simplifying device installation.

“Although it’s estimated that marine energy could supply up to 2 GW of UK electricity demand by 2020 and significantly more than this by 2050, the electricity costs need to be more competitive with established renewable and conventional generation.

“Achieving significant operating cost reduction is critical to the long-term development and success of the marine energy industry in the UK. Projects of this nature will benefit any marine device developer and it has the potential to benefit other offshore energy installations.”