MechChem Africa September-October 2023

The world’s first offshore hydrogen production plant

Lhyfe, Europe’s green and renewable hydrogen producer, has announced that Sealhyfe, the world’s first offshore hydrogen production pilot, is now producing green hydrogen from a floating wind turbine in the Atlantic Ocean off Le Croisic on the West Coast of France.

Sealhyfe is now connected via a subsea hub to a floating wind turbine, proving the feasibility of producing hydrogen offshore under the toughest conditions.

A fter an initial phase of trials at quay, the Sealhyfe hydrogen pro duction platform has now been connected to France’s Centrale Nantes ’ SEM-REV offshore testing site, in the Atlantic 20 km off the French coastal town of Le Croisic. Sealhyfe is now con nected via a subsea hub to a floating wind turbine, entering the second trial phase to prove the feasibility of producing hydrogen offshore under the toughest conditions. This represents a historic step towards new clean energy based on the large-scale production of green hydrogen. At the outset of this project, Lhyfe wanted to prove the technical feasibility of produc ing hydrogen offshore and to acquire the op erational experience needed to quickly scale up offshore production as a gamechanger in decarbonising the fuels needed for trans portation and industry. The company therefore voluntarily chose to expose Sealhyfe to the toughest conditions. It is being tested under real conditions on a floating platform, re engineered from a WAVEGEM platform by GEPS Techno to stabilise the production Designed to meet unprecedented challenges

unit at sea. The system is connected to Centrale Nantes ’ SEM-REV offshore testing hub operated by the OPEN-C Foundation, which is already linked to a floating wind turbine, FLOATGEN, engineered and oper ated by BW Ideol. The Sealhyfe platform meets several key challenges, including: • Performing all stages of hydrogen production at sea, ie, converting the electrical voltage from the floating wind turbine; pumping, desalinating and purifying the seawater; and break ing the water molecules via electrolysis to obtain renewable green hydrogen. • Managing the effects on the system from the platform’s motion at sea: listing, accelerations, swinging move ments, and much more. • Enduring environmental stress: Sealhyfe will have to survive premature ageing of its components as a result of corrosion, impacts, temperature variations, etc. • Operating in an isolated environ ment: the platform must operate fully automatically, without the physical intervention of an operator, except for scheduled maintenance periods that have been optimally

integrated from the design phase. Lhyfe and its partners have designed, built, and assembled all the technology necessary for producing hydrogen offshore – including the 1.0 MW electrolyser supplied by Plug – in just 16 months. The Sealhyfe platform, which is less than 200 m 2 , can produce up to 400 kg of hydrogen a day, which is approximately equivalent to generating 13.2 MWh/day of electricity. By 2030-2035, offshore could represent an additional installed hydrogen generation capacity, equivalent to around 3.0 GW, for Lhyfe. The eight months of on-quay trial From September 2022 to May 2023, Sealhyfe was moored at the Quai des Frégates , in the Port of Saint-Nazaire. Lhyfe and its partners have thus been able to draw knowledge from a series of start-up tests to approach the second phase of the project with confidence, and to get the most out of the trials. Tests included: • Benchmarking: Hundreds of tests were carried out at quay to record the precise behaviour and performance of the platform, so that they could be compared with the Phase 2 trial results via the thousands of sensors installed

42 ¦ MechChem Africa • September-October 2023