French firm launches phase one of full-scale wave energy tests

France’s wave energy developer Seaturns has launched phase one of full-scale trials for its wave energy conversion system at Nantes Saint-Nazaire Port, marking a key step in the company’s transition from design to real-world implementation.

After six months of manufacturing and assembly, the Bordeaux-based company completed the construction of its full-scale demonstrator – a 42-ton steel unit measuring 15 meters in length and six meters in diameter, designed to deliver 200 kW of nominal power.

“This fundamental step is the culmination of ten years of R&D and the hard work of a team entirely dedicated to this demonstrator. It’s a huge achievement to finally be able to see it in full size. This success is also that of all those who have placed their trust in us,” said Vincent Tournerie, CEO and Founder of Seaturns.

According to the company, several key operations have already been carried out during the first testing phase, including launching, buoyancy checks, boarding and safety procedures, and the disassembly and reassembly of the electrical conversion module.

In just two hours, the maintenance operations were completed with light resources and a small team, a result that Seaturns said confirms the simplicity and cost-effectiveness of at-sea interventions.

“We have validated the safety of operations and begun to demonstrate the effectiveness of maintenance, thus confirming the feasibility of interventions at sea. This success paves the way for more economical and robust operation of our solution,” said Arthur Chauliac, Test Manager at Seaturns.

Following the port-based trials, Seaturns said it plans to begin phase two in early 2026, with open-sea testing aimed at verifying the demonstrator’s performance and robustness in real marine conditions over at least one year. 

The campaign will also include environmental impact assessments, paving the way toward industrialization and commercial deployment by the end of 2026.

The testing campaign is part of the IAS-WEC project, supported through the i-Nov competition managed by Bpifrance and ADEME, and co-financed by the French state via the France 2030 program and the EU-backed France Relance plan. Key partners include MECASOUD, Nantes Saint-Nazaire Port, and Pôle Mer Bretagne Atlantique.

In July, Seaturns secured €2.45 million to support the industrialization and deployment of its wave energy technology, following a fundraising round backed by 1,543 investors on the LITA.co platform.