Decommissioning of tidal energy platform

Scottish engineering partners, Ocean Kinetics and Green Marine (UK) have successfully completed the first phase of decommissioning a tidal energy platform at EMEC’s Falls of Warness test site in the Orkney Islands.

The contract to decommission the facility, which was previously operated by OpenHydro to streamline its tidal turbine technology, was awarded by EMEC in early April this year.

Managing director of Ocean Kinetics, John Henderson, said: “We are delighted to be partnering with Green Marine (UK) on this project, which is proceeding to plan in fairly challenging tidal conditions.

“The test rig has two steel piles, which are drilled and grouted into the seabed, with a steel superstructure forming the work area. Two steel collars were attached to the piles for raising and lowering the device into the tide with 15 tonne hydraulic winches. We were contracted to remove the steel superstructure, cut the piles, disconnect and terminate the cables.

“The superstructure has been removed and we are now working on the pile removal and cable termination.”

Ocean Kinetics divers, riggers, welders and ROV operators are deployed alongside Green Marine’s offshore management, vessel, mooring and operational cable services, with both companies carrying out the operational engineering, cutting and heavy lifts.

John Henderson continued: “This project demonstrates how well placed we are to deliver contracts of size and scale in challenging conditions. We have created a formidable team – drawing on the expertise and experience of both companies in managing a wide range of complex marine-related projects – from decommissioning and retrieval of fishing boats and aquaculture-related barges and equipment to subsea servers and port gates.”

To return the seabed to its original condition, diamond wire cutting machines will cut each pile foundation flush to the seabed.

OpenHydro was the first developer to use the tidal test site at the Fall of Warness off the island of Eday when its test rig and 250kW open centred turbine were installed in 2006. The device was the first tidal turbine to be grid-connected in Scotland and subsequently the first to successfully generate electricity to the national grid in the UK. Investment in tidal energy by OpenHydro’s parent company ceased in 2018.