Towards sustainable mobility

Global transport demand is expected to increase due to the combined influences of population growth and economic development. To ensure that CO2 - neutral fuels can provide for an increasing fraction of this demand, both demand side measures and advances in Vehicle technology are required. Specific fuel consumption may be lowered by decreasing the energy demand at the wheel (lighter vehicles with lower air and rolling resistance), by using highly efficient converters such as fuel cells, and by advanced systems design that allows for the recuperation of braking energy. Low temperature polymer electrolyte fuel cells combined with regenerative electricity storage in supercapacitors represent a particularly promising option, as they combine an attractive cruising range with ultra-low emissions. A future sustainable transport technology must be based on renewable fuel supplies. Distribution infrastructure is a key issue in the introduction of synthetic fuels from renewables. Waste biomass and solar energy may be used for the CO2 - neutral production of gases with high calorific value (synthesis gas, hydrogen). Synthesis gas from biomass gasification may be combined with hydrogen from renewable sources (hydroelectric power, solar electricity) to produce methanol as a carbon dioxide neutral, renewable fuel. The potential of solar chemistry for the production of solar fuels is described. Life cycle analysis is the appropriate tool to choose among the many possible energy chains (from primary energy to propulsion energy). These issues will be analysed with a view to assessing CO2 mitigation options in the transportation sector.