Possible Hydrogen Transitions in the UK: Critical Uncertainties and Possible Decision Points

Many energy system optimization studies show that hydrogen may be an important part of an optimal decarbonisation mix, but such analyses are unable to examine the uncertainties associated with breaking the ‘locked-in’ nature of incumbent systems. Uncertainties around technical learning rates; consumer behaviour; and the strategic interactions of governments, automakers and fuel providers are particularly acute. System dynamics and agent-based models, and studies of historical alternative fuel transitions, have furthered our understanding of possible transition dynamics, but these types of analysis exclude broader systemic issues concerning energy system evolution (e.g. supplies and prices of low-carbon energy) and the politics of transitions. This paper presents a hybrid approach to assessing hydrogen transitions in the UK, by linking qualitative scenarios with quantitative energy systems modelling using the UK MARKAL model. Three possible transition pathways are explored, each exploring different uncertainties and possible decision points, with modelling used to inform and test key elements of each scenario. The scenarios draw on literature review and participatory input, and the scenario structure is based on archetypal transition dynamics drawn from historical energy system transitions, reflecting insights relating to innovation system development and resistance to change. Conclusions are drawn about appropriate policy responses.