Subsea cable laid for HiWave-5 Project

The 100-tonne cable was installed using Maersk’s Maersk Achiever vessel, and it will provide power and data connection from an on-land substation to the demo site 5.5km offshore.

CorPower’s Wave Energy Converter (WEC) will later form part of a larger four-system array, which will make it one of the world’s first grid-connected wave farms.

To install the cable, the Maersk Achiever was first positioned in a safe water depth within the cable corridor roughtly 1km offshore.

“A messenger line was passed from an onshore winch to the Maersk Achiever, and then connected to a pull-in head,” said Marine Operations manager Robert Argo. “As the cable was being deployed, buoyancy was attached to assist with the cable float into shore. Once onshore, the cable was pulled through a pre-installed cable conduit running under the beach and into the on-land substation, while the remaining cable was deployed using an onboard cable tensioner.

“During the lay operation, cable protection was added to provide additional mass where required for on-bottom stability. Various parameters were also monitored throughout including cable tension, cable departure angle and touch down monitoring. On completion a visual and positioning survey was carried out by a remotely operated vehicle.

“The cable lay process is a notoriously challenging aspect for marine energy projects, with much planning required and adaption to weather windows and ocean conditions. We are thankful to our highly diligent and professional partners, including Maersk Supply Service for their close support throughout the operation entire.”

CorPower is now gearing up for the arrival of the C4 PTO (Power Take Off) system, which has completed a rigorous one-year dry test programme in Sweden. Once transported the PTO will be integrated with a composite hull, which was custom built at CorPower Ocean’s Portuguese base, in Viana do Castelo.

The WEC will later be fused to the cable through a quick-connect interface located at the anchor-head. While providing power connection to feed electricity to shore through the 7.2kV cable it will also deliver high speed communication to the wave farm through fibre optic cores.