Is Green Hydrogen an Environmentally and Socially Sound Solution for Decarbonizing Energy Systems Within a Circular Economy Transition?

Green hydrogen (GH 2 ) is expected to play an important role in future energy systems in their fight against climate change. This study, after briefly recalling how GH 2 is produced and the main steps throughout its life cycle, analyses its current development, environmental and social impacts, and a series of case studies from selected literature showing its main applications as fuel in transportation and electricity sectors, as a heat producer in high energy intensive industries and residential and commercial buildings, and as an industrial feedstock for the production of other chemical products. The results show that the use of GH 2 in the three main areas of application has the potential of contributing to the decarbonization goals, although its generation of non-negligible impacts in other environmental categories requires attention. However, the integration of circular economy (CE) principles is important for the mitigation of these impacts. In social terms, the complexity of the value chain of GH 2 generates social impacts well beyond countries where GH 2 is produced and used. This aspect makes the GH 2 value chain complex and difficult to trace, somewhat undermining its renewability claims as well as its expected localness that the CE model is centred around.