HERSO: Development of a Highly Efficient and Robust Solid Oxide Electrolyzer system for hydrogen production


HERSO: Development of a Highly Efficient and Robust Solid Oxide Electrolyzer system for hydrogen productionVoltaChem, its founding partner TNO and the industrial partner Hygear initiated the HERSO project to accelerate the integration of Solid Oxide Electrolyzer (SOE) for hydrogen production in the process industry. Through this project, a novel concept of a highly efficient pressurized SOE stack technology and a simplified balance-of-plant (BoP) are aimed to achieve a cost reduction of the overall SOE system for a lower cost production of hydrogen.

Toward decarbonization of the industry

Large scale green hydrogen production by means of water electrolysis is one of the important solutions to achieve the Energy Transition and to meet the CO2 emission reduction goals. Solid Oxide Electrolysis (SOE) offers the most efficient way (20-30% more efficient compared to Alkaline and PEM electrolysis) to produce green hydrogen, due to its operation at high temperature allowing favorable thermodynamics and kinetics for conversion of steam into hydrogen and direct industrial process integration. Especially in countries like the Netherlands, with a large exothermic energy and petrochemical sector (Rotterdam, Geleen, Zeeland and Delfzijl), which all produce excess of steam, SOE becomes highly interesting, due to its capability of direct reuse of steam as feedstock. First field ready systems, manufactured by Haldor Topsoe, Sunfire, Genvia and Solid Power, are already available on the sub-MW scale, while 100MW scale systems are expected to be in operation in 2024. To enhance the competitiveness of SOE to the project contributes to the CAPEX reduction target (80-90%) which is prognosticated by Hydrogen Europe (EU Joint Undertaking European Industrial & Research parties dealing with electrolyzer systems) in 2030 and to improve system lifetime of SOE electrolyzer systems.

HERSO aims for pressurized SOE technology

HERSO aims at a (CAPEX and maintenance) cost reduction of the SOE electrolyzer system, and accelerating economic viable integration of the SOE electrolyzer system in the industrial environment.

The HERSO project goals will be achieved by focusing on increasing efficiency and lifetime of the SOE stack technology and simplification of the SOE system by increasing stack and system operating pressure. The following activities contribute to this focus:

  • System design study on the SOE system addressing an improved operational match between stack and balance-of-plant design resulting in lower CAPEX and OPEX (lower maintenance, higher efficiency) for the overall SOE system
  • Development of a novel SOE short stack concept, with integration of robust performing SOE cells able to operate at improved current density and lifetime for pressurized H2-SOE operations (3-10 bar)
  • Assessment of the robust SOE system and integration potential in the industrial environment

This project is co-funded by the Topsector Energie of the Dutch Ministry of Economic Affairs and Climate Policy, in the program TKI NieuwGas.

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Claire Ferchaud

Lead Scientist - Solid Oxide Electrolysis




Frans van Berkel

Scientist - Solid Oxide Electrolysis



Ties van Maaren

Senior Business Developer

+31 6 212 348 41



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