Comparison of the environmental damage caused by vehicles with different alternative fuels and drivetrains in a Brussels context

A comprehensive methodology has been developed to compare the environmental damage caused by vehicles with different alternative fuels, such as CNG, LPG, etc., and drivetrains, such as electric and hybrid drives. This paper describes how the environmental effect of vehicles should be defined and includes parameters concerning vehicle emissions and their influence on human wellbeing and the environment. It then describes how the environmental effect of vehicles could be defined, taking into account the availability of accurate and reliable data. Rating systems are analysed as a means of comparing the environmental effect of vehicles, allowing decision-makers to dedicate their financial and non-financial policies and measures as a function of the ecological damage. Different types of pollution (acid rain, photochemical air pollution, noise pollution, etc.) and their effect on numerous receptors such as ecosystems, buildings and human beings (e.g. cancer, respiratory diseases, etc.) and global warming are considered. The methodology described, known as Ecoscore, is based on a methodology similar to life cycle assessment (LCA) which considers the part played by emissions in certain types of damage (e.g. by using the exposure-response damage function). Total emissions involve oil extraction, transport and refinery, fuel distribution and electricity generation and distribution (well-to-wheel approach). Emissions due to the production, use and dismantling of the vehicle (cradle-to-grave approach) should also be considered. The different types of damage are normalized to make comparisons possible. Hence, a reference value (determined by a chosen reference vehicle) will be defined as a target value (the normalized value will thus measure a kind of distance to target). The contribution of the different normalized types of damage to a single value—Ecoscore—is based on a panel weighting method. This new approach differs from other methodologies in that it has been especially developed for the assessment of the environmental effect of vehicle emissions in an urban context, such as the Brussels Capital Region. Additionally, this methodology not only considers conventional vehicles but can also evaluate all alternative fuels and drivetrains with new vehicle technologies. Some examples of Ecoscore calculation are illustrated.