CNH2 promotes knowledge on electrolysis in Enagás’ new OTH report

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The National Hydrogen Centre (CNH2) has actively participated in the preparation of the second report of Enagás’ Hydrogen Technology Observatory (OTH), entitled Renewable hydrogen production by electrolysis: current status and technology outlook.

The publication of this report represents a significant milestone for the renewable hydrogen sector, as it provides a technical, rigorous and up-to-date overview of one of the key technologies for the decarbonisation of the economy and the achievement of European climate objectives.

CNH2’s contribution has been particularly significant, with four members of its staff participating as authors:

  • Jesús Rodríguez Ruiz, Head of the CNH2 Scientific Development Unit
  • Luis Alberto Lara, Engineer at the CNH2 Scientific Development Unit
  • Vanesa Sendarrubias Carbonero, Engineer at the CNH2 Consultancy and Training Unit
  • Enrique Saborit Rojas, Engineer at the CNH2 Consultancy and Training Unit

Content and main contributions of the report

This technical report, with a strong dissemination focus and open public access, is presented as an essential guide for industry and investors, offering a comprehensive view of the state of the art, key technical fundamentals and development prospects of water electrolysis as the main pathway for renewable hydrogen production. The document addresses both the physicochemical principles of the process and its large-scale industrial application, and contextualises the role of renewable hydrogen within the European regulatory framework, including the classification of renewable fuels of non-biological origin (RFNBOs) and the targets established in the RED II and RED III Directives.

Among the most relevant aspects is the comparative analysis of the main electrolysis technologies currently available or under development: alkaline (ALK), proton exchange membrane (PEM), anion exchange membrane (AEM) and solid oxide electrolysis cells (SOEC). The report assesses their level of technological maturity, efficiency, advantages and limitations, as well as the main innovation trends in the sector.

The report also examines the structural components of electrolysers and the water consumption associated with the process, which ranges between 17 and 22 litres per kilogram of H₂, well below that required by conventional fossil-fuel-based routes with CO₂ capture. In addition, it explores in depth the factors influencing the efficiency of electrolysis systems and analyses the levelised cost of hydrogen (LCOH)—considered a key indicator for assessing the competitiveness of renewable hydrogen—together with ongoing cost-reduction strategies.

In this context, the integration of electrolysis with the electricity system is addressed, highlighting the role of the electrolyser as a flexible consumer capable of absorbing surplus renewable generation, contributing to grid stability and enabling energy storage through the concept of sector coupling. This approach is complemented by the analysis of water purification and reuse technologies, which enable sustainable large-scale production.

Finally, the report provides a broad overview of projects, initiatives and support programmes at both European and national levels, such as the European Hydrogen Bank, the European Electrolyser Partnership and hydrogen-related PERTE programmes, together with the main databases and platforms identified for monitoring the technological and geographical deployment of projects—both in Spain and at European and global levels.

Overall, this second report of the Hydrogen Technology Observatory confirms that water electrolysis is not only a strategic, cross-cutting and continuously evolving technology, but also a true driver for renewable integration, industrial decarbonisation and European energy autonomy—positioning Spain and Europe as technological leaders and global benchmarks in the hydrogen economy.

CNH2’s continued commitment to knowledge generation

CNH2 had already contributed to the preparation of the first report of the Hydrogen Technology Observatory, with the participation of Saborit and Sendarrubias, focused on the analysis of the use of hydrogen derivatives, such as ammonia and methanol, as maritime fuels and their potential to contribute to the decarbonisation of maritime transport.

With its involvement in this second report, CNH2 consolidates its position as a national benchmark in research, development and technical advisory services in hydrogen technologies, reinforcing its contribution to the transition towards a more sustainable and competitive energy system.

The full report can be consulted via the following link.