Anchor concept could mark sea change for wave power generation

Engineering experts at the University of Dundee are preparing to make waves in the ocean energy industry with new anchoring technology for the next generation of offshore power generating devices.

Members of the Geotechnical Engineering group, based within Dundee’s School of Science and Engineering, are developing new novel vibro installed anchors aimed at making wave energy converters (WECs) more cost efficient.

The team are working on the concept with wave energy developer Corpower Ocean, as part of the UMACK Project, which is to be trialled off the coast of Portugal.

Professor Michael Brown, from Dundee’s School of Science and Engineering, said, “Our Geotechnical Engineering group has extensive experience in developing new foundation and anchoring concepts for the offshore renewable energy and aquaculture sectors.

“We were approached by Corpower Ocean and Ternan Energy to further develop their anchoring concepts, utilising our world-leading experimental and physical testing facilities, developed as part of the Scottish Marine and Renewable Test Centre (SMART). These testing facilities include the large geotechnical centrifuge testing centre, which is the only one of its kind in Scotland along with our unique experience in advanced numerical modelling.

“It is a huge honour to work with Corpower Ocean and Ternan Energy on such important work that will contribute to the deployment of Corpower Ocean’s C4 Wave Energy Converter and is a testament to the expertise and facilities that we have in Dundee that led to their initial approach.”

The UMACK Project presents a step change in technology for the ocean energy space addressing issues around affordability, durability and reliability of marine power system’s mooring and anchoring.

Matt Dickson, UMACK Project Manager and Corpower Ocean Head of Projects, said the partnership marked a significant breakthrough adding greater resource and intelligence.

“The consortium members are thrilled to be expanding our partnership with the University of Dundee’s Geotechnical Engineering group, which has extensive experience developing new foundation and anchoring concepts for the offshore energy and aquaculture sectors,” he said.

“The department benefits from world-class facilities, combined with unparalleled experience. This is helping us to push the boundaries and reimagine the traditional mooring and anchoring process.”

The team’s new vibro installed anchors are being developed as an alternative to classic drag embedment anchors, which are not able to establish the required tensile capacity that allow a wave energy convertor to cope with the millions of waves it will face in its lifetime, and also to replace gravity base and large diameter plain pile anchor solutions which are both very expensive, structurally inefficient and require very large vessels to handle and deploy.

Instead, the new concept anchors are “vibrated” into the seabed, providing the required capacity whilst avoiding the need for alternative pipe pile anchors to be driven into the ocean floor, a noisy process known to be detrimental to marine life. Driving these piles is also incredibly expensive, often forming in the region of 30-40% of developments costs of a new offshore generation site, with the vibro anchors likely being significantly cheaper option.

The team’s concept anchors are undergoing final testing before they are deployed for demonstration and certification at the Aguçadoura wave farm in the Atlantic Ocean.

Professor Brown added, “Developing the concepts in a university research environment using scaled physical modelling means that all of the important influencing factors can be controlled and understood, allowing these concepts to progress in technology readiness level (TRL) at a fraction of the cost of doing this as a full-scale offshore demonstration project.

“This latest work builds on ten years of experience of developing anchoring foundation systems at the University of Dundee for the oil and gas, renewable energy and aquaculture sectors. We have been lucky enough to work on cutting edge concepts for the future of renewable energy, such as foundations and anchors for tidal stream generators, novel anchoring for WECs and alternative foundations and anchors for fixed and future floating wind.

“It is hoped that these research efforts will have the potential to revolutionise future offshore renewable energy development as part of the low carbon agenda.”

The UMACK Project is led by a European consortium including geotechnical specialist Ternan Energy, wave and tidal energy developers Corpower Ocean and Sustainable Marine Energy Limited, mooring experts TTI Marine Renewables, EMEC (European Marine Energy Centre) and marine renewable energy modelling experts from the University of Edinburgh.

UMACK is funded by Scottish Enterprise and the Swedish Energy Agency with co-funding from the OCEANERA-NET COFUND (via the European Commission under Horizon 2020).