New study raises questions around eco credentials of Green Hydrogen

They warned that the vast majority of green hydrogen is currently made using fossil fuels, raising questions about the validity of its role as an environmentally-friendly power source.

Professor Lenny Koh, professor of operations management at the University of Sheffield, who also led the study, said: “Green hydrogen is seen as the answer to the world’s energy crisis in terms of reducing our reliance on imported fossil fuels, however at present, approximately 96 per cent of hydrogen is made using fossil fuels. We cannot be successful in using hydrogen to reach net zero if fossil fuels are still playing such a huge role in the hydrogen supply chain.

“Our research suggests that hydrogen could still live up to its promise and play a vital role in the clean energy transition, but only if the electricity used to produce it comes from genuinely low-carbon sources and the full supply chain is designed with sustainability in mind.

“Aligning green hydrogen technology selection with regional decarbonisation trajectories is crucial for achieving sustainable and resilient international supply chains by 2050.”

Led by Professor Koh, researchers evaluated 20 possible scenarios for producing and transporting green hydrogen across 14 countries from 2023 through to 2050. The countries included were the UK, Japan, China, France, Norway, Canada, Germany, South Korea, the USA, Austria, Ireland, Poland, Italy, and the Netherlands – all of which were chosen because they are currently world leaders in hydrogen development.

The research focused on five different ways of making hydrogen fuel, three of which used electrolysis and two of which used biomass systems, the current main production methods globally.

Results show that in 2023, electrolysis technologies had the highest global warming impacts, mainly due to their energy-intensive operation, maintenance and manufacturing stages, as well as how the electricity used in these systems largely came from grids that were powered by oil, gas or coal.

The research also suggests that making hydrogen via proton exchange membrane – a type of electrolysis – could be the most sustainable option by 2050, if the grids supplying the electricity have moved away from fossil fuels.

Many of the study’s scenarios project substantial reductions in greenhouse gas emissions by 2050, as long as electricity grids become cleaner and countries shift towards renewable energy. In some cases, hydrogen supply chains could reduce key environmental impacts by more than 90 per cent compared with current hydrogen production.

Dr Moein Shamoushaki, research associate at the University of Sheffield’s Management School and co-author on the study, said: “Our research is clear that the sustainability of green hydrogen very much depends on energy mix and supply chains.

“Any delays in policy implementation or disruptions to renewable energy deployment could substantially alter the relative sustainability of green hydrogen supply chains.

“Our findings offer valuable insights for governments and policymakers on shaping green hydrogen production, supply chains, and policies that align with global and national net-zero and sustainability goals.”

According to the research, one of the most environmentally-friendly supply chains could involve both the UK and US, should they meet their clean energy ambitions.

This scenario is based on manufacturing hydrogen in the UK using proton exchange membrane, with significant exports to the United States.

Researchers said this could support the US and UK’s ambition to transition to a more resilient energy system by 2050.

The study, Sustainability of green hydrogen technologies depends on energy mix and supply chain, is published in Nature Communications Sustainability.