Fuel Cells and Hydrogen Joint Undertaking (FCH JU) logo

Hydrogen admixtures in the natural gas grid - FCH-04-2-2018
Deadline: 24 Apr 2018   CALL EXPIRED

EU logo mono Fuel Cells and Hydrogen Joint Undertaking (FCH JU)

 International Cooperation
 Aerospace Technology

Specific Challenge:

Injecting hydrogen admixtures into the natural gas network can contribute significantly to solving the problem of transporting and storing surplus electricity generated from renewable resources (see e.g. working document on Energy storage – the role of electricity SWD(2017) 61). There are, however, a number of challenges for the existing gas grid infrastructure and end use equipment to operate safely with the admixture of hydrogen (H2NG). In order to establish a European understanding of an acceptable hydrogen concentration in the natural gas system, a number of knowledge gaps need to be filled. Depending on the hydrogen concentration, among other parameters, different components of the gas system or end-user appliances and processes may be affected. Generally, the addition of hydrogen to natural gas influences gas properties and therefore operational aspects, functionality of devices and appliances, degradation of materials and infrastructure requirements (safety and functionality). The performance and safe operation of existing industrial turbines, industrial burners and residential burners have been identified as critical issues that need to be addressed on short term to enable the further uptake of hydrogen in the natural gas grid (e.g. see the Final Report of the CEN - CENELEC Sector Forum Energy Management/Working Group Hydrogen). For turbines and burners, the actual impact of a continuous and likely varying supply of H2NG on the combustion is to be verified with the potential impacts on the safety of appliances and applications and the impacts on efficiency, lifetime and environmental performance (e.g. NOx emissions). Results from previous and ongoing national and EU projects should be considered (e.g. NaturalHy, GASQUAL, HIPS, DOMHYDRO, GRHYD, HyDeploy, etc.).
Power-to-gas systems injecting admixtures of 2% have been widely demonstrated, further demonstrations of up to 20% (e.g. GRHYD, HyDeploy) are underway and it has been shown that such systems can operate to provide grid services and absorb surplus renewables. However, the economic factors in progressing from natural gas to H2NG blends within the gas grid have yet to be established. An exhaustive techno-economic evaluation of admixture of hydrogen into the natural gas grid adapted to the local, regional or national situation should therefore be undertaken, with a particular focus on policy options. Such an evaluation should identify all relevant cost drivers, benefits and risks, considering both technical and financial aspects. Cost efficient strategies for adapting the infrastructure can then be developed and a roadmap for the injection of hydrogen prepared to support a macro-economically feasible transformation path towards higher limits for allowable hydrogen concentrations in the gas system.


The scope of this topic encompasses a techno-economic assessment in addition to pre-normative research activities. There are two main activities to be carried out:

1. Pre-normative research on critical issues related to end-use applications and equipment.
The core of the topic is the evaluation of the actual impact of H2NG mixtures on the combustion process (flame speed, shape, temperature, emissivity, emissions) of end-use applications, and equipment: their safety, efficiency and lifetime across a wide range of hydrogen concentrations. Whereas hydrogen concentrations around 20 vol% can be considered a long term goal, already now 10 vol% of hydrogen are feasible in some parts of the natural gas system. Close to CNG stations, 2 vol% hydrogen is today a limiting factor due to the use of steel tanks for CNG vehicles. The hydrogen concentrations used for testing should be chosen accordingly.
An assessment should be performed aiming at the selection and clustering of end-use applications. An in depth assessment and analysis of previously carried out research shall be undertaken, including an analysis on the transferability of results. This analysis should be used to guide the selection of applications. The selection of critical end-use applications to be further investigated shall be done according to the following criteria and dimensions:

  • Prioritisation of critical end-use applications in terms of sensitivity and resistivity to H2NG. Giving a fair balance between the sensitivity of the segment to H2NG and the market share among applications;
  • For a number of low, medium and high hydrogen concentrations, identify if and what adjustments and design changes are required for
    • (i) gas burners as used in common domestic/commercial/light industrial/industrial equipment (i.e. boilers, cookers, gas heaters, ovens, dryers, furnaces etc.) and
    • (ii) gas heat engines (reciprocating engines and gas turbines);
  • Integrating the new gas technologies (e.g. micro-cogeneration, gas heat pumps, fuel cells) that will play an increasing role in the future;

Pre-normative research on end-use appliances and equipment, including control devices, should be performed based on this selection and prioritisation work, aiming at assessing compatibility, performance and lifetime of end-users applications (or their critical components such as burners, engines), under conditions not yet covered by other studies. It should be ensured that already installed gas appliances and equipment can continue to function safely and with a satisfactory level of efficiency and environmental performance when supplied with H2NG instead of natural gas for low, medium and high hydrogen concentrations.
Appliances certification aspects (including re-certification needs) should be considered. To investigate combustion behaviour and its influence on the mentioned criteria of material compatibility, performance and lifetime, the experimental campaign should be chosen representing as far as possible real operative conditions, and full components should be preferred (as far as possible) to downsize laboratory samples. This pre-normative research can include the development of testing methods and procedures.
The project should develop a suitable detailed experimental program, which should be derived from agreed priorities at European level. Appliances compliant with the Gas Appliance Directive, both domestic and non-domestic, will be evaluated. Common burner types used for large commercial and industrial boilers as used in ovens, dryers, furnaces etc. should also be investigated. Common types of gas engines should be considered.
The combustion parameters Wobbe index, methane number and laminar flame speed should be considered. Different compositions of H2 gas should be taken into account. Fluctuations in the concentration of hydrogen will have to be considered as well.
Tests should be carried out for boilers, cookers, water heaters, space heaters, μCHPs, gas heat pumps, fuel cells and gas engines following an appropriate testing protocol. The tests should include an evaluation of the sensitivity of the application to hydrogen and consider the impact on safety, efficiency, reliability, lifetime, CO, NOx and other possible impacts.
Test gases used for the certification of gas appliances by notified bodies (as required by the Gas Appliance Directive), include for the gas group most widely used in Europe test gas G222 consisting of 77 % CH4 and 23 % H2. It is however used only for tests of a short duration. Longer-term testing, also with higher H2 concentrations should be carried out. Tests should assess the potential long-term effects of hydrogen. Validated accelerated stress testing should be performed, considering gas quality fluctuations and changes in environmental conditions.
The impact of H2 content on NOx levels, for which European legislation sets lower limits than previously should be verified.
For gas engines specifically, the effect of hydrogen on knock and pre-ignition should be investigated, as well as on the control systems.

2. Techno-economic assessment including analysis of policy options to enable the wide adoption of H2NG blends.
A techno-economic analysis, identifying plausible remuneration frameworks and policy options needs to be undertaken to ensure that the respective stakeholders (i.e. renewable power generators, electricity grid operators, gas network and storage operators as well as H2NG customers) can realise the benefits of adopting H2NG blends. There are several policy options to consider (including government imposed targets for the decarbonisation of gas grids, a higher carbon tax on natural gas for funding the implementation of H2NG, a voluntary Guarantee of Origin scheme for the gas industry, the removal of taxes and levies on electricity used by power-to-gas systems and feed-in-tariffs for various concentrations of H2NG).
Further analysis should then be undertaken to consider cost drivers and policy options for enabling a progression in the concentration level, as a function of the findings of the first challenge related to end-use appliances and equipment. The assessment of the regulatory hurdles that prevent the increased uptake of hydrogen in the natural gas grid and its use by end-user applications will have to be mapped, considering individual EU Member States' limitations. A pre-requisite for the work to be performed is an overview of the materials, components and equipment actually present in the gas chain at European level. The entire gas chain including all end-users of natural gas should be considered. Based on the outcome of the assessment, cost efficient strategies for adopting H2NG blends, ownership and operating models for injecting H2NG blends and policy suggestions should be prepared to support a macro-economically feasible transformation path from low to high hydrogen concentrations in the gas system.
It is expected that proposal will include appliance and burner manufacturers, power-to-gas technology providers, gas consumers and gas industry.
Any safety-related event that may occur during execution of the project shall be reported to the European Commission's Joint Research Centre (JRC) dedicated mailbox JRC-PTT-H2SAFETY@ec.europa.eu, which manages the European hydrogen safety reference database, HIAD.
Test activities should collaborate and use the protocols developed by the JRC Harmonisation Roadmap (see section 3.2.B "Collaboration with JRC – Rolling Plan 2018"), in order to benchmark performance of components and allow for comparison across different projects.
International collaboration with member countries of the International Partnership for Hydrogen and Fuel Cells in the Economy (IPHE) is specifically encouraged for this topic.

The FCH 2 JU considers that proposals requesting a contribution of EUR 2.75 million per project would allow this specific challenge to be addressed appropriately. Nonetheless, this does not preclude submission and selection of proposals requesting other amounts.
A maximum of 1 project may be funded under this topic.
Expected duration: 3 years.

Expected Impact:

The proposed techno-economic assessment and pre-normative research will enable an easier and wider development of injection of hydrogen admixtures into natural gas networks, supporting deployment of hydrogen technologies and contributing to decarbonisation of the European energy system and to European energy security goals. This will be achieved by comprehensive knowledge of cost drivers and policy options at European level. The project will ensure that the safe operation of existing and future gas appliances and applications is not jeopardised by the supply of H2NG instead of the natural gas composition range for which they have been designed and certified for; and identify categories of existing appliances and equipment that would need to be replaced as the hydrogen concentration is increased.
The expected impacts of the project include:

  • Establishing how much hydrogen can be added to natural gas without changing the existing certification of appliances. Establishing how the existing certification can be adapted to possibly allow higher concentration of hydrogen, including the related additional costs, and the required changes to common gas burners to combust such mixtures;
  • Improved knowledge on effect of H2NG on common burner types used for large commercial and industrial boilers as used in ovens, dryers, furnaces, including necessary adjustments and design changes;
  • Recommendations for revision of EN or ISO standards or drafting of new standards based on PNR results and review of the existing testing methods;
  • Mapping of EU member state regulations limiting the hydrogen concentration in the gas system and identification of critical regulatory bottlenecks including proposal to address those;
  • Identification of policy options, remuneration frameworks and operational models for enabling the wide adoption of hydrogen admixtures in European gas networks.
  • Developing an EU level roadmap for the increase of hydrogen concentration in natural gas up to 2030;

The efforts related to the experimental part of the pre-normative research on end-use applications are estimated to be about 70% of the total budget.

Type of action: Research and Innovation Action
The conditions related to this topic are provided in the chapter 3.3 and in the General Annexes to the Horizon 2020 Work Programme 2018– 2020 which apply mutatis mutandis.

Cross-cutting Priorities:

International cooperation

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