Prospective techno-economic and environmental assessment of a national hydrogen production mix for road transport

Fuel cell electric vehicles arise as an alternative to conventional vehicles in the road transport sector. They could contribute to decarbonising the transport system because they have no direct CO2 emissions during the use phase. In fact, the life-cycle environmental performance of hydrogen as a transportation fuel focuses on its production. In this sense, through the case study of Spain, this article prospectively assesses the techno-economic and environmental performance of a national hydrogen production mix by following a methodological framework based on energy systems modelling enriched with endogenous carbon footprint indicators. Taking into account the need for a hydrogen economy based on clean options, alternative scenarios characterised by carbon footprint restrictions with respect to a fossil-based scenario dominated by steam methane reforming are evaluated. In these scenarios, the steam reforming of natural gas still arises as the key hydrogen production technology in the short term, whereas water electrolysis is the main technology in the medium and long term. Furthermore, in scenarios with very restrictive carbon footprint limits, biomass gasification also appears as a key hydrogen production technology in the long term. In the alternative scenarios assessed, the functional substitution of hydrogen for conventional fossil fuels in the road transport sector could lead to high greenhouse gas emission savings, ranging from 36 to 58 Mt CO2 eq in 2050. Overall, these findings and the model structure and characterisation developed for the assessment of hydrogen energy scenarios are expected to be relevant not only to the specific case study of Spain but also to analysts and decision-makers in a large number of countries facing similar concerns.