This project marks the completion (Phase 2c) of a programme of work delivered in support of CEN and Technical Committee CEN/TC408 initiated by DG Ener, aimed at revision of the standards for and therefore removal of barriers to introduction of biomethane into gas networks and vehicles. By ensuring that the appropriate standards are fit for purpose at time of revision, the work will ensure that costs of biomethane injection are optimized, and there are no undue burdens on producers. This work is expected to enable growth of the biomethane industry and confidence that investments can be made in biomethane production and injection. It will therefore help to ensure the removal of barriers to achieving the RePowerEU target of 35BCM of biomethane by 2030 by aligning needs of producers, transporters and end users. The programme is therefore highly relevant in advancing regulatory work for greening the gas grid under the Green Deal. It is also relevant for implementing RED II with maximum impact. In cooperation with CEN TC 408, its stakeholder community and DG Energy, GERG has developed and has been delivering a workprogramme to address the removal of barriers identified which will enable standardization: Phase 1 - funded by GERG members to identify barriers SA/CEN/RESEARCH/475/2017-07 (2018-2019) – Phase 2a - experimental work on siloxanes, and a literature study on impacts of sulfur, impacts of oxygen, particularly related to underground storage and corrosion, and health impacts. SA/CEN/RESEARCH/475/2019-09 (2020-2022, Phase 2b, ongoing) – continued experimental work on siloxanes, commencement of experimental campaign on sulphur, and on oxygen impacts. Improving specific knowledge on biomethane at the European level, particularly in relation to impact of feedstocks, The project proposed here (2022-2024, Phase 2c) - Completion of the experimental and literature campaigns begun in Phase 2b to support the delivery by CEN TC 408 and update of the standards.

Hydrogen has emerged as a required fuel and commodity needed for the decarbonization of the generation, distribution, storage, and energy consumption. Through the EU Hydrogen Strategy, the EC recognised the important role of hydrogen, and the need for the hydrogen market to be significantly scaled up. The boost in hydrogen production and its introduction in the energy market has arised one important issue: leakage of hydrogen during its storage, transportation and distribution. This leakage produces two negative side effects: there is a safety issue derived from the hydrogens broad flammability range (4 to 74% concentration in air) and it contributes to a net emmission of greenhouse gases (GHG) by depleting hydroxyl radicals (OH), thus increasing the atmosperic lifetime of methane and influencing tropospheric ozone formation, with an estimate accumulation effect of 5.8% increase over 100 years. The Green2TSO-OPTHYCS project will aim to develop new sensor technologies for continuous leak detectors based on optical fibre sensors technologies which will lead to an increase in the safety level of hydrogen applications, from production to storage and distribution, both in new infrastructure, working with pure H2, and in natural gas repurposed installations and pipelines, contributing to a safe and economically viable implementation of H2 production, transport, and storage processes. OPHTYCS project is built upon 3 conceptual areas: A) Technology pillars analysis and definition of new sensor technology , B) Validation of key use cases (pipelines, HRS and midstream sites (compression , metering stations, etc.) of the new technologies in 3 different controlled validation sites, and C) Aspects of the technologies derived from the use cases, including the assessment of the security and environmental risks evaluations and regulatory framework, and a scalability and cost efficiency study.

Green hydrogen is gaining moment across Europe as feedstock, fuel or energy carrier and storage, as solid actions are needed to reach carbon neutrality by 2050. Hydrogen has many possible applications across industry, transport, energy and building sectors and, therefore, local gas grids across Europe are working hard to get ready for its transport. The realization of the prospects of delivering H2/NG admixtures or even 100 % H2 by existing gas distribution grids exacerbates the problem of pipe integrity due to the well-known negative impact of hydrogen on the mechanical properties of metals. Most projects assessing safe hydrogen compatibility with natural gas distribution grids (i.e. H21, HydePloy,etc.) have performed experiments to study the leakage ratio, emission potential and explosion severity of vintage components. However, long-term material integrity assessment replicating distribution grid operating conditions in testing platforms is still necessary. CANDHy will allow the possibility of testing relevant metallic materials, different from the well-studied steels, with a methodology involving simultaneous test in independent R&D platforms with a common methodology. This will allow to obtain trustful and reproducible results about hydrogen tolerance of materials that have not been considered in previous research but that are an essential part in in low-pressure gas grids. CANDHy project will enable hydrogen distribution in low pressure gas grids by consolidated and exhaustive scientific data, coupled with harmonized guidelines for non-steel metallic grid materials. At least five material grades of different families (such as cast iron, copper, brass, lead, aluminium), both new and vintage, will be fully documented, and the results will be publicly available for all stakeholders in a continuously updated database. Mechanical tests will base on static and dynamic conditions to assess hydrogen sensitivity following the most relevant current and updated standards

THyGA main goal is to enable the wide adoption of hydrogen and natural gas (H2/NG) blends by closing knowledge gaps regarding technical impacts on residential and commercial gas appliances. For this purpose, THyGA will: •Screen the portfolio of technologies in the domestic and commercial sectors and assess theoretically the impact of hydrogen / natural gas admixture in order to have a quantitative segmentation of the gas appliance market and a selection of the most adequate products to be tested •Test up to 100 residential and commercial gas appliances (hobs, boilers, CHP, Heat pumps, etc.) and how 200 Million of European gas appliances will react to various H2 concentration scenarios •Benchmark and develop pre-certification protocols (test gases) for different level of H2 in natural gas for coming integration in standardization, these protocols will be validated through tests •Make recommendations for manufacturers, decision makers and end-users along the gas value chain to enable mitigation strategies for retrofit THyGA will provide an extensive understanding of previous projects or studies related to H2NG admixture utilization with domestic and commercial appliances. Through extensive testing programme, the project will establish the impact of hydrogen concentration in natural gas on safety and performances of a large set of domestic and commercial appliances. Hence, THyGA will support recommendations for revising EN or ISO standards or drafting new standards and will fully support and secure FCH-JU’s “Hydrogen Roadmap Europe” (2019). THyGA project gathers 9 renowned partners including 4 research centres, 3 industries, 1 SME, and 1 association covering the whole value chain of natural gas. The extensive advisory panel includes manufacturers, European and International Associations and DSOs included in H2/NG blends projects ensuring a constant challenge of the processed results and a great opportunity for a wide dissemination/communication plan to share results.

How much hydrogen (H2) is released from the value chain? To answer the question is very challenging since insufficient and, when available, no standardized data can be found in the literature. However, it is essential to cover this knowledge gap to perform any credible and scientifically validated research regarding the H2 value chain impact on the climate change. The literature is full of studies investigating and calculating the risk of H2 leakages in case of failures, accidents, and emergencies. But significant knowledge gaps exist about the amount of anthropogenic H2 (in the atmosphere) from the H2 value chain. The research community needs to address this by improving the capability to quantify small and large releases, delivering validated methodologies and techniques for measuring or calculating them. A universally accepted and open-access inventory is needed as soon as possible. Likewise, an open access and comprehensible tool that is easy to be used is also asked by the stakeholders to better quantify the leaks from the whole in H2 value chain while the momentum is fast gathering to upscale H2 energy applications. The NHyRA project is specifically designed to address these urgent needs. The project will deliver a "H2 releases" inventory to serve as a reference for the scientific and industrial community. New or adequately adapted experimental, theoretical, and simulation methodologies will be validated to perform laboratory or in-field measurements to achieve the ambitious goal. Experimental tests will also be performed on the most critical elements of the H2 value chains by the partners of the Consortium. A complete picture of the H2 releases' scenarios in the middle (2030) and long (2050) term will be developed to enable decision-makers to identify and prioritize effective mitigation actions. And finally, the project will formulate recommendations for Standards and Technical Specifications.