‘Bubble-free’ electrolyser start-up plans Rotterdam pilot after €2.7m raise

Estonian-Dutch start-up Spiral Hydrogen plans to pilot its “bubble-free” alkaline rotating electrolyser technology at the Port of Rotterdam, after raising €2.7m ($3.2m) in pre-seed funding.

Spiral confirmed to H2 View the funding would support the development of a 10kW pilot system to begin commercialising the technology, which it claims can deliver efficiencies of over 90% (HHV).

The accumulation of hydrogen and oxygen bubbles on electrode surfaces can impair electrolyser efficiency due to surface coverage. Spiral said its system uses centrifugal force to sweep electrolytes while directing the gases through separate channels.

Spiral told H2 View this removes the need for separate pumps and cooling systems, lowering costs while preventing buildup and allowing for high electrical efficiency.

The pilot project will be carried out with the SwitcH2, the hydrogen subsidiary of the floating oil and gas firm BW Offshore, and the Port of Rotterdam Authority. After the initial 10kW installation, Spiral intends to follow up with a 100kW system.

While the systems are early stage, rotating alkaline electrolysers could eventually pose a major step change in electrolyser performance, offering a route to consistently high efficiencies by eliminating bubble-induced losses.

However, questions remain around mechanical complexity, long-term durability under rotation, and the scalability of such designs to industrial capacities.