Green Hydrogen's Role in Decarbonising Industries
Green hydrogen in industrial supply chains
Industrial gas markets are beginning a transition from fossil hydrogen to electrolytic hydrogen produced with renewable electricity. However, the climate benefit depends entirely on the carbon intensity of the electricity grid and the way life-cycle emissions are measured. In many industrial settings, green hydrogen can deliver substantial carbon savings compared to grey hydrogen made from natural gas. Nevertheless, the actual emissions profile varies widely depending on power sources, electrolyser manufacturing, and transport infrastructure.
The practical question for UK manufacturers, refiners, and chemical producers is whether green hydrogen delivers genuine emissions reductions or simply shifts carbon from one part of the supply chain to another. As procurement specifications and public sector tenders increasingly require low-carbon industrial inputs, businesses need to understand how green hydrogen is defined, certified, and priced.
How green hydrogen is produced and measured
Green hydrogen is made by splitting water into hydrogen and oxygen using electricity from renewable sources such as wind or solar. The International Energy Agency confirms that hydrogen from electrolysis produces no emissions at the point of generation. However, the total carbon footprint includes upstream emissions from manufacturing electrolysers, building renewable generation capacity, and transporting compressed or liquefied hydrogen to end users.
According to the IEA, electricity used for electrolysis must emit less than 200 to 240 grams of carbon dioxide per kilowatt-hour for the process to be cleaner than conventional steam methane reforming, the dominant method for making grey hydrogen from natural gas. Consequently, grid-powered electrolysis in countries with high coal or gas generation can produce hydrogen with a carbon intensity close to or even higher than fossil-derived alternatives.
Life-cycle assessments show significant variation. Offshore wind-powered hydrogen typically emits between 0.4 and 0.8 kilograms of carbon dioxide equivalent per kilogram of hydrogen produced. Solar-powered systems can be higher depending on location and panel manufacturing emissions. Meanwhile, a 2024 study published in Nature Energy found median production emissions of 2.9 kilograms of carbon dioxide equivalent per kilogram of hydrogen in an optimistic configuration, with transport and compression adding further emissions. MIT research indicates that green hydrogen can emit one kilogram of carbon dioxide or less per kilogram of hydrogen if the renewable supply chain is genuinely low-carbon, whereas grey hydrogen typically emits around ten kilograms and blue hydrogen with carbon capture falls somewhere in between.
European and international policy definitions
The European Commission has set a threshold requiring low-carbon hydrogen to achieve at least 70 per cent greenhouse gas savings compared to unabated fossil fuels. This standard applies across the EU and influences procurement criteria in UK supply chains serving European clients or subsidiaries. Therefore, businesses exporting to the EU or bidding for contracts with European parent companies must demonstrate compliance with this benchmark.
The International Renewable Energy Agency recommends that emissions accounting should cover the whole life cycle, from electrolyser manufacturing through to hydrogen delivery. IRENA also advocates for origin guarantees and emissions labelling to ensure transparency and prevent greenwashing. In practice, this means that hydrogen sold as