How hydrogen blending can help towards decarbonizing gas systems

09 May 2022 | News

MARCOGAZ is pleased to attend the World Hydrogen Decarbonising the Gas Grid Conference in Barcelona, on 9-10 May, gathering gas TSOs and DSOs, policymakers, and technology enablers from around the world to share their plans and priorities for future gas infrastructure, with real-world case studies and a focus on the regulatory, economic, and technical landscapes. MARCOGAZ’s Secretary-General Manuel Coxe will chair the second day of the event, addressing the panel “Use of Hydrogen Blending as a Decarbonisation Solution” and moderating the session where hydrogen case studies THyGA, HyCARE, HypSter and HyNet projects will be presented.

Hydrogen blending process consists on the integration of concentrations of hydrogen into existing natural gas pipelines whose purpose can be either economical (to foster hydrogen market) or environmental (to reduce the carbon intensity of the methane). Blending hydrogen alongside other gases into the existing gas grid is considered a possible first step towards decarbonising natural gas systems taking into consideration technical, economic and regulatory peculiarities.

As part of its Hydrogen Strategy, and more recently the REpowerEU, the European Commission aims to make widespread use of green hydrogen possible “across all hard-to-decarbonise sectors” from 2030 and beyond. The Commission stated that if new infrastructure is needed, it should be hydrogen compatible. The Commission’s strategy on hydrogen further notes that the specific infrastructure needs will depend on the patterns of development of production and use of hydrogen.

Effectively, the injection of hydrogen into the existing gas grid could provide a quick and affordable transitional solution to handle the lack of an immediately available dedicated hydrogen infrastructure. Moreover, the injection of hydrogen provides the option of having access to renewable and low-carbon energy, up to a certain level, for all gas consumers connected to the gas network.

Overall, the gas sector has identified three solutions when it comes to the transportation of hydrogen across pipelines:

  • Retrofitting (e.g., blending of hydrogen with natural gas)
  • Repurposing
  • Construction of new dedicated hydrogen infrastructure


Depending on the share of hydrogen to be injected, the gas network might need concrete retrofitting actions. The extent to which modifications are required depends on multiple aspects related to technical characteristics of concrete segments of the gas system. The retrofitting of the networks brings challenges that can be technically solved in an affordable way for hydrogen shares up to a certain limit. MARCOGAZ studies have revealed that at relatively low hydrogen concentrations (up to 10% H2 in volume), the gas system may not require major investment or modifications, while higher shares of hydrogen concentration may require significant investment — depending on the topology of the gas grid, distance of transport, equipment in the gas system and acceptance of H2 and natural gas mixtures by the end user.

Challenges and advantages

Blending has numerous advantages as well as challenges which can be overcome with the right policy, regulatory and technical decisions.

Technical challenges including the effect on pipeline materials, adaptation of valves, compressors and metering instruments, and treatment of other gases in underground storage with blending have been largely identified and solutions have been addressed. Furthermore, research and development on hydrogen transport via pipelines (transport and distribution) is considered a priority by the industry and policymakers.

Blending facilitates the transport of low-scale production of hydrogen to end users, contributing to decarbonisation of the gas system. The process fosters the hydrogen market towards a future hydrogen-based economy and takes advantage of the excessive renewable power to store a considerable amount of energy in gaseous form. Concrete pilot projects have demonstrated the effective advantages of using blending of hydrogen with natural gas as a plausible solution to decarbonize the gas grid.