Germany's gas grid can absorb only very limited hydrogen, advisory council says

Blending hydrogen into Germany's existing gas distribution networks is technically feasible only within very tight limits and offers modest climate benefits relative to the effort required, Germany's National Hydrogen Council (NWR) said in a report. The independent government advisory body warned that without major regulatory reforms, blending risks diverting investment away from the dedicated hydrogen infrastructure Germany will need regardless.In the fight against climate change, hydrogen made with renewable electricity is seen as a remedy for sectors with particularly stubborn emissions, such as heavy industry and aviation. Germany has set out to become a global leader in the associated hydrogen technologies, and the government has penned a National Hydrogen Strategy to fulfil these ambitions, but it is failing on its targets, with both supply and demand remaining well below expectations. Green hydrogen blending – feeding hydrogen produced from renewable electricity into existing gas pipelines – has been debated across Europe as a potential bridging strategy to decarbonise the gas system before dedicated hydrogen networks are built. Germany has set a target of ten gigawatts of electrolyser capacity for green hydrogen production by 2030, but the question of how to transport and distribute it remain unresolved.The council’s report highlights a fundamental problem with volume-based thinking: a 10-percent hydrogen blend by volume translates to only around 3 percent of the gas mixture's energy content, and cuts emissions only by roughly 2 percent, assuming the hydrogen is fully “green” and was produced using only renewable electricity. At 30 percent hydrogen by volume, emissions fall by around 7 percent, but such shares are technically unachievable across most of the network.Germany's high-pressure transmission network is effectively limited to around 2 percent hydrogen by volume due to cross-border EU gas quality rules and the needs of industrial users such as chemical plants and refineries, which require stable gas quality and can be damaged by higher hydrogen concentrations, the council said. Distribution networks – the local pipes serving homes and businesses – have no binding hydrogen limit, but face a different set of obstacles: there is no comprehensive registry of what appliances are connected where, some older equipment tolerates no hydrogen at all, and hydrogen production from renewable electricity peaks in summer, when gas demand is at its lowest.“Blending hydrogen into the gas network, at both the transmission and distribution network levels, is only possible within very narrow limits without a fundamental overhaul of the legal and regulatory framework,” the council concluded.

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