Option for a sustainable passenger transport sector in 2050

SUMMARY The current transport sector faces two global problems. The first is climate change, due to the combustion of fossil fuels, and the second is resource depletion. From the entire transport sector (road, air and water), private passenger vehicles account for more than 50% of the emitted greenhouse gasses. The main question is: will there be a sustainable solution for private passenger vehicles in 2050? The aim of this research is to find potential bottlenecks when the entire society switches to one singe alternative. For example when we will still be using the Internal Combustion Engine (ICE) in 2050 or when we all switch to Battery Electric Vehicles (BEV), Fuel Cell Electric Vehicles (FCEV), Biofuel vehicle or perhaps a combination in the form of a Hybrid vehicle. The definition of a sustainable situation is not to rely on fossil fuels and the demand for resources (material, land, renewable energy) is not larger than the reserves or potential. Current CO2 emissions (3500 Mton/yr) from the private passenger vehicle sector are expected to increase by a factor 2 according to the business-as-usual (BAU) scenario. In this scenario, the total amount of vehicles will increase to about 2 billion and the global travelled distances will increase with a factor of 2.3 by the year 2050. A sustainable CO2 situation is a reduction of 50% compared to the 1990 levels, which means 1175 Mt/yr. With the use of fore- and backcasting scenarios, the most important bottlenecks of each alternative are examined. Improving ICE vehicles, for example with direct injection, mass reduction, engine downsizing, variable gearboxes, decreases resource use and total CO2 emissions by more than 50%. Unfortunately, these measures can only stabilize current CO2 emissions in 2050, due to the increase in global travelled kilometers. Furthermore, these vehicles still use fossil fuels. Improved ICE vehicles cannot become a sustainable solution in 2050. When biofuels substitute fossil fuels, ICE vehicles are much cleaner. The potential of 1st generation biofuels is technically large enough to cover the demand, but emissions of producing it vary enormously and therefore these vehicles cannot become sustainable in 2050. The potential of 2nd generation biofuels is unfortunately smaller and is therefore not enough to cover the demand. Electric vehicles store their energy in NGA-G lithium batteries (BE vehicles) or in hydrogen (FCE vehicles). The main bottlenecks of BE vehicles are the relatively low energy density of batteries, the accumulated lithium demand and the CO2 intensity of current electricity production. The lithium reserves are only large enough to produce BE vehicles with a battery that can cover a vehicle range of 400-500 km. Charging these batteries with the current electricity mix would only stabilize current CO2 emissions in 2050. These vehicles can only become sustainable when at least 80% of the electricity is generated by renewable electricity sources. FCE vehicles do not have a direct resource bottleneck but faces an overall low efficiency (hydrogen production, transport and fuel cell efficiency) of 30%. For these vehicles, at least 90% of the electricity has to be generated by renewable electricity sources. Both are within the potential of renewable electricity sources such as wind, water and solar power but large investments have to be made to supply this demand. A Plug-in hybrid electric vehicle (PHEV) is a combination of a BE vehicle and a combustion engine to extent the range (