Engineer Sciences and Social Sciences Dialogues face to the Hydrogen Mobility Challenge

Mobility, i.e. the movement of people within a geographical space, whatever the purpose and duration, plays a structuring role in our societies. Various mobility solutions coexist, centered on technological objects (e.g. bicycle, car, bus, train, boat, plane) or even involving multimodal combinations.

The 20th century saw the emergence, organization and imposition of a system of mobility, particularly individual mobility, based on the combined use of fossil fuels and internal combustion engines. But after a century of intensive exploitation, available and known fossil resources are beginning to run out. The growing pressure of energy demand in the face of limited supply is having an impact on energy prices. What's more, recognition of the anthropogenic nature of climate change and increasingly detailed knowledge of its social and environmental consequences are leading to efforts to contain global warming. According to the International Energy Agency, it is necessary to reduce CO ₂ emissions from this sector by at least 80% by 2050 relative to its 2000 level to achieve a target of stabilizing temperature rise at less than 2.4°C. The development of the urban structure and the explosion of megacities coupled with the accelerating use of individual vehicles generate significant noise pollution and a sharp deterioration in air quality. Even if it is not the most emissive sector, the expansion of transport and mobility needs is resulting in an increase in the relative contribution of this sector to greenhouse gas and particulate pollutant emissions.

All of these factors are calling into question the current mobility system. We therefore need to address a host of technological, economic and societal challenges to support the profound transformation of this activity, with the overall aim of decarbonizing society.

Technological advances in electromobility, and more specifically in hydrogen-powered fuel cell vehicles, are part of this trend. When it comes to electromobility, battery-powered electric vehicles are not the only alternative to internal combustion engines. The possibility of using fuel cells (henceforth PAC) powered by hydrogen-oxygen-rich fuel (Hy-PAC) is a realistic alternative, contributing to the transition to sustainable mobility, as hydrogen emits no CO ₂ . These PAC vehicles are characterized by the mobilization, on a principal (power source) or complementary basis ("range extenders" or range element), of a fuel cell system in the powertrain that transforms chemical energy into electrical energy. Since the beginning of the 21st century, several cities around the world have been experimenting with hydrogen-powered buses, as well as fleets of...