COMPETITIVE ENERGY CARRIERS FOR TRANSPORTATION: A COMPARISON BETWEEN ELECTRICITY AND HYDROGEN

Hydrogen has been presented in the recent past as an ideal solution to many constraints related to the global energy problem both from a social and an environmental point of view. The potential role of hydrogen has been confused, and probably even today it is still partially confused, with the wider range of opportunities related to fuel cell technologies and to CO2 sequestration techniques, that both have their own significance in the power generation sector independently of an hydrogen based energy economy. This paper proposes a critical analysis of the possible roles that hydrogen may have in the future as an energy carrier. The discussion is based on the status of current and mature technologies, on forecasts about upcoming opportunities for hydrogen production, management and use, and on general environmental, social and economical considerations. The attention is focused on the transportation sector, where recent scientific studies have proposed well-to-wheel primary energy consumption comparisons between several scenarios, in the long term, for vehicle propulsion, based on the analysis of the whole global life cycle and the overall induced environmental impact. For zero-local-emissions urban transportation, these studies indicate that both battery operated fully electric vehicles and hybrid vehicles have the potential to offer greater differential advantages from a global point of view, than hydrogen operated fuel-cell vehicles