How the Boundaries of the Supply Chain Affect Climate Profile: The Case of Renewable Electricity and Green Hydrogen for Italy and the UK

Green hydrogen obtained from renewable electricity can play an essential role in the decarbonization of different sectors. The reliability of the data used to model the entire supply chain is a crucial parameter in Life Cycle Assessment. In this study, the authors show how photovoltaic and wind electricity supply chains influence the carbon footprint of green H2. While most published studies rely on default datasets from commercial libraries, the current work exploits the actual supply chain of the PV panels and builds an updated average European wind turbine supply chain. The updated values for PV-based H2, experiencing a 40–60% reduction, are 2.7 and 1.8 kg CO2 eq./kg H2 for the UK and Italy. The carbon footprint of UK offshore wind-based H2 can be reduced up to 24% and get close to 0.6 kg CO2 eq./kg H2. The findings emphasize the sensitivity of the final climate profile generated by the processes upstream of the electrolysis system.