Tadek Ocean Engineering had designed an innovative mooring and cable solution for the pioneering Renewables for Subsea Power (RSP) project, combining wave energy with subsea storage to power subsea equipment.
The system developed by Aberdeen-based Verlume connects Mocean Energy’s Blue X wave energy converter with a Halo underwater battery storage system. Having recently completed a 12-month test program off the coast of Scotland, the £2 million project aims to reach the finish line this spring.
Tadek Senior Engineer Nigel Terry who led the prestigious design project said the novel mooring and ‘lazy wave’ cable solutionallows the device to weathervane, without inhibiting the energy capturing motion. The robust and reliable design is able to withstand extreme motions and excursion.
In addition, Tadek managed the procurement of the cable and mooring system, while producing installation procedures with Leask Marine.
“A key aspect of the design was Tadek’s bespoke swivel unit which incorporated a mechanical swivel for the mooring and a slip ring for electrical, said Mr Terry. “This was a complex and challenging design without precedent which succeeded against formidable odds, and was tested above the design conditions and fatigue life. Not often as a designer are you given such free reign, and our work on the RSP Project pays testament to the trust which clients have in us to make executive decisions and take responsibility for the work.”
The industry-supported project, situated 5km east of Orkney Mainland, demonstrates the integration of green technologies to deliver consistent and sustainable low-carbon power and communication to subsea equipment. It aims to demonstrate a cost-effective alternative to umbilical cables, known for their carbon intensity and lengthy procurement and installation processes.
Energy companies including TotalEnergies and Shell Technology – Marine Renewable Program have partnered with project in a pan-industry effort, which also includes participation from PTTEP, the Thai national oil company, Serica Energy, Harbour Energy, Baker Hughes, Transmark Subsea, and the Net Zero Technology Centre (NZTC).
In October 2023, the East coast of Scotland suffered extreme weather conditions for a sustained period, with the arrival of Storm Babet. Tadek’s mooring and umbilical designs, installed a year prior, were subjected to 6-7m wave heights. The infrastructure remained firmly in place with the device continued to deliver power.
“The test programme has been a tremendous success,” said Andy Martin, Chief Commercial Officer at Verlume. “This phase of RSP was initially conceived as a four-month at-sea demonstration, but the quality of data and the robustness of our combined technologies as well as tremendous support from the oil majors, led us to extend the programme to a full year. We now have increasing confidence in the reliability and the commercial potential of this system.”
The final phase of the RSP Project will involve the removal of all equipment from the site, ahead of inspection and clean down onshore in Orkney and at Verlume’s operations facility in Dyce, Aberdeen.
“All technology providers will examine critical components for wear and tear against performance metrics defined both individually and as a fully integrated power and communications ecosystem,” said Ian Crossland, Commercial Director at Mocean Energy. “A key part of this process will be assessing lessons learned and any future upgrades that may be required for a fully commercial system.”
The joint industry participants and developers are currently assessing near-term and future strategies for additional deployment or potential testing on live assets.
This may encompass the deployment of a similar project in Scottish waters, and/or new projects overseas, to showcase how the combination of green technologies can facilitate dependable low-carbon power and communication to subsea equipment in a live environment.
