Minimizing carbon dioxide emissions from transport is now a major objective worldwide. Most often the in-use emissions are the measurement criteria but it is plain that whole of life emissions, including all embodied energy and the consequent CO2 at all phases of production use and end of life (scrapping and or recycling) should be included. So what is the optimum strategy for minimizing energy use and emissions, recognizing that the car is the prime source of personal space for mobility, and that many governments support a focus on battery electric vehicles (BEVs) as the solution for the future? The purpose here is to compare the long-term CO2 emissions from current gasoline cars with BEVs and to examine the option of natural gas fueled internal combustion engine cars using gas from three alternatives: conventional gas from wells and biogas from either renewable inputs or from waste carbonaceous materials. From this to forecast the optimum service life (before scrapping including recycling) against a back drop of steadily improving efficiency in fuel use, battery manufacture, increasing renewable sourced electricity, energy storage and vehicle efficiency. From published data on vehicle manufacturing energy, battery production energy and vehicle usage data, life cycle analysis (more than ‘well-to-wheel’) is performed and concomitant CO2 emissions from all stages of the vehicle life cycle.

University of Melbourne, School of Engineering: Harry C Watson