Activity analysis based framework for economic and environmental modelling and evaluation of hydrogen pathways

In the discussion of the reduction in greenhouse gas emissions, the use of hydrogen as an energy carrier in different parts of the transport sector is regarded as one option to reduce transport-based emissions. In this context, the selection of an efficient pathway from production to consumption is crucial in the total hydrogen supply chain. Various pathways in terms of production, transport and storage technologies already exist, and with advances in research, new options continue to emerge. These pathways are associated with different costs and emission characteristics, which strongly depend on the considered setting. In this paper, a methodology is proposed that allows for flexible modelling and evaluation of hydrogen pathways. The methodology is based on the concept of activity analysis. Pathways are modelled as sequences of activities with all associated material flows and emissions. This allows for both economic and environmental assessments of different hydrogen pathways in an integrated manner. The applicability of this approach is demonstrated within a case study for two different use cases in the context of the supply of hydrogen refuelling stations for road transport. First, we show how different delivery pathways for a specific sourcing option can be evaluated. Second we apply the proposed method for the integrated assessment of different sourcing options, locally procured grey hydrogen and imported green hydrogen. By enabling an economic and environmental evaluation, the methodology allows for the identification of efficient solutions.