Realizing potential

Emma Gordon

June 1, 2015

Tidal and wave energy projects are getting grid-wet this year, yet there’s still more to learn. Emma Gordon reports from All Energy.

An OpenHydro device.
Image from OpenHydro.

The wave and tidal energy industry should be optimistic about the future of marine renewables, given the range of technologies being developed and deployed.

Yet, after a tough 3-4 years, more needs to be done in areas such as collaboration, investment and industrialization to make wave- and tidal-based energy more competitive and cost-effective in comparison to other resources, specifically offshore wind.

That was the message during a panel session, chaired by Rob Stevenson, president of Ocean Energy Europe, during the All Energy Exhibition and Conference in Scotland in early May.

Wave and tidal presentations during the show covered the global market, research and development as well as project updates.

Carnegie Wave Energy’s Perth Wave Power project.
Image from Carnegie Wave Energy.

Tidal

Garrett Connell, project development manager at Ireland-headquartered OpenHydro, says 2015 is a milestone year for the company, with delivery on both sides of the Atlantic of two of the world’s first grid-connected tidal arrays.

In the Bay of Fundy, Nova Scotia, OpenHydro is working with Emera to deploy two of its 2MW, 16m, seabed-installed open-center turbines. Offshore Brittany, France, at EDF’s Paimpol-Bréhat site, another two 16m turbines will be installed and connected later this year.

Elsewhere, the second phase of the Canadian array will ultimately use the existing infrastructure at the Fundy Ocean Research Centre for Energy (FORCE) facility.

“In 2017, we’re aiming to increase capacity by adding a further six turbines, bringing it to 16MW,” Connel says. “From then, we’ll build out on a phased basis from 50MW to 300MW in the 2020s.”

Carnegie Wave Energy’s CETO 5 and CETO 6 units.
Image from Carnegie Wave Energy.

Wave

Learnings from Carnegie Wave Energy’s Perth Wave Energy (PWE) project, using its CETO 5 unit, will help develop the next generation of wave technology, with projects due to be commissioned in Australia and the UK during the next three years, says Tim Sawyer, CEO at CWE UK, the UK subsidiary of Australia’s Carnegie Wave Energy.

Sawyer says 2015 will see further development of the CETO 6 project, which will be built near the three-unit PWE CETO 5 array off Garden Island, Western Australia. The CETO 5 PWE project is currently the world’s only operating, grid-connected wave-energy project, he says.

Submerged CETO buoys convert wave energy into zero-emission electricity and desalinated water.

Since grid connection in February, the Perth Wave Energy project has experienced sea states of up to 4.8m and accumulated more than 8000 hours of operation. The first unit is due to be removed, inspected and serviced in May.

Each next-generation CETO 6 unit will have a 1MW power capacity, around four times that of its predecessor, and, unlike CETO 5, the technology will be capable of offshore power generation.

“Essentially [CETO 6 buoys] can operate deeper, further offshore and in more exposed sites,” Sawyer says. “It opens out different markets to us. We’ll be deploying three of these units in Australia...They’ll be commissioned in 2017, constructed next year. We’ll take those learnings and bring them to UK Wave Hub project [off Cornwall, England] with construction [scheduled for] 2017 and commissioning thereafter.”

Lessons learned

Neil Kermode. 
Image from EMEC.

Neil Kermode, managing director of the Orkney-based European Marine Energy Centre, which provides accredited open-sea testing facilities, emphasized the importance of collaboration, both globally and cross-industry.

He also acknowledged the importance of, and contribution from, a vibrant supply chain. “We believe [making it work] is an international endeavor,” he says. “It’s fundamentally important we find a way to work together to harvest energy in a proper, sustainable way, and as efficiently as possible.”

He says specific lessons have to be learned for a concept to work and be commercially viable. “It has to be able to be installed, able to supply, be reliable, be able to be maintained and you have to be able to operate it before you can say it has a life in the market because it’s cost effective. If you don’t learn those lessons, you won’t get to the bottom line… all of these lessons are being learned by a variety of people [along the supply chain] and not purely us.”

Hi Flo 4 vessel update

Mojo Maritime’s Hi Flo 4 (HF4) vessel has the capacity to both accelerate the installation of tidal systems and reduce costs for the offshore wind and oil and gas industries, according to company chairman Martin Wright.

A deployed OpenHydro device.
Image from FORCE.

He says the HF4, designed to carry out installation maintenance and decommissioning operations, can dynamically position itself in up to 10 knots of tidal stream, compared to five knots for standard dynamic positioning vessels. This increases the operational window, reducing installation time and cost.

“The quicker you get a wind or tidal turbine working, you massively improve the economics, [because] you’ve got revenue coming in,” he says.

Mojo Maritime analyses shows the vessel can potentially install tidal turbines for less than £1million per MW, which is less than the cost of many offshore wind projects.

“In terms of getting one of these built, we need a contract to build it,” he says. “This is a piece of supply chain equipment that can massively improve the chances of accelerating the building of [tidal] projects. We need to think about these tools…. It’s not just about the turbines themselves, we need the complete system,” Wright says. Mojo Maritime was bought by UK-based James Fisher and Sons earlier this year.