Orkney’s tidal energy tripod set for forensic scrutiny

The European Marine Energy Centre (EMEC) has hired Leask Marine to remove a tripod foundation from the Fall of Warness tidal energy test site as part of an EU-backed collaborative decommissioning project.

Tripod foundation (Photo: TGL)

The decommissioning operations will feed into a collaborative FORESEA-funded project called FoDTEC (Forensic Decommissioning for Tidal Energy Converters) that will produce a report which is expected to benefit the wider ocean energy sector.

The project involves Blackfish Engineering Design, the International Centre for Island Technology (ICIT), Rovco, and Brunel Experimental Techniques Centre, Brunel Centre for Advanced Solidification Technology and Brunel Design.

The FORESEA support package will focus on conducting forensic analysis to obtain a comprehensive understanding of the end-of-life condition of the tripod, which was first installed in 2009, and ascertain the long-term effect of deploying components and systems in the sea, according to EMEC.

Forensic examination techniques will focus on biofouling and metallurgic analysis as well as collation of a detailed photographic record of the decommissioning activity for future reference.

A lessons-learned report resulting from the project will offer best-practices for device and infrastructure design, deployment, operation, maintenance, and decommissioning for developers to minimize decommissioning costs and de-risk future projects.

Nic Wallet, FORESEA Program Manager at EMEC, said: “The tripod has remained in situ at the Fall of Warness to give the potential for it to be usefully repurposed, however so far EMEC’s clients have preferred to have clear access to test berths. Therefore, we made the decision to remove the tripod, taking the opportunity to address the lack of decommissioning that has taken place in the industry to give clearer insight into the latter stages of a technology’s lifecycle.

“The project was formed to conduct forensic analysis and share the learning with developers and other test centers to ensure that the works are of maximum use to the industry. Through sharing lessons learned and implementing them into future device designs and operations, we expect to positively impact the LCOE for ocean energy.”

Decommissioning is a critical part of the lifecycle of any ocean energy project but is not yet well explored as relatively few technologies have progressed to the decommissioning stage following long-term deployment, and limited resources force focus on the development and demonstration phases of prototype projects, EMEC said.

Tim Warren, Engineering Director at Blackfish, added: “This project offers a fantastic opportunity to learn about the decommissioning process, as well as to provide valuable learning to developers in the field of long term biofouling and corrosion effects. Until now, there have been few opportunities to study tidal stream sub-sea infrastructure that has been in place for nearly 10 years.”