French start-up poised to catch the wave to real sea trials

With the support of several European Union-funded research projects, the French wave energy start-up Seaturns has made significant advancements in the development of its wave energy technology, brining it only one step short of demonstration in real sea environment.

Over the last few years, Seaturns has been developing a wave energy converter based on a patented innovative anchoring system the company claims could present a breakthrough for wave energy sector.

Somewhat difficult to define in traditional terms, Seaturns’ wave energy converter can be seen as a floating oscillating wave surge converter using the principle of the oscillating water column, according to the company’s project manager Gabriel Canteins.

After various technical and economic studies, accompanied by tank tests across Europe, validated the robustness and performance of the system, Seaturns is ready to take the next step in advancing its technology through try-outs in real sea conditions.

To get its technology to the current technology readiness level (TRL) at 3-4, meaning the scale technology prototype underwent tank testing with subsystem designs in process, Seaturns has been riding on a wave of European Union’s research funding through initiatives like Portos Project, MaRINET2, and Marine Energy Alliance.

Seaturns’ technology works by having mooring lines coiled around the device, covering the surge induced by the incident swell into pitch.

Using this principle, a cylindrical float whose axis is parallel to the wave crest is set into oscillatory pitch motion. The mooring line is held at both ends by two anchors and two submerged buoys to keep the necessary tension.

Within the cylinder, a water pendulum induces compression and decompression cycles into two separate air-filled chambers.

The pressure differential between the two chambers generates an oscillatory air flow, which is ran through an air turbine that produces electricity.

Most recently, Seaturns conducted two weeks of testing at research institute IH Cantabria in Spain, using its Coastal and Ocean Basin facility.

The trials made, supported by the MaRINET2 programme, made it possible to test a wave energy converter at a scale of 1:10, which represents a great advancement in Seaturns’ research and development process, according to the company.

With the technical support of marine renewables engineering consultancy Innosea, the scale testing allowed for proving an energy capture turbine and moorings representative of current practices in the offshore sector.

“Thanks to European programmes like MaRINET2, Marine Energy Alliance and Portos Project, we have advanced our technology technically and economically. We are now ready to take the next step – the sea trials”, Seaturns’ project manager Canteins said.

Once developed, the full-scale device is expected to be 9-12 metres long, spanning six metres in diameter, with the expected rated power at between 100-200kW, Canteins revealed earlier.

The device will be suitable for multiple applications, including electricity generation, desalination, hydrogen production, and for other uses in offshore energy and tourism industries.

Before that, however, the technology needs to undergo a demonstration in real sea environment to show its readiness to face harsh conditions often encountered at open sea.

In this regard, Seaturns plans to launch a fundraising campaign with a couple of options being explored, including crowdfunding and attracting support from angel investors.

“We are in contact with several platforms, it’s quite soon to specify the one we’ll work with. We need €500,000 in equity to finance the design, manufacture and tests a prototype at sea. The choice of the testing site is not fixed at this stage”, Canteins concluded.