Direct and Indirect Water Consumption in Vehicle Manufacturing

There is a growing need to include the availability of water sources as a design criterion because future forecasts suggest that water demands will increase significantly while freshwater resources are being depleted. In this paper, we focus on the amounts of water that are consumed in automotive vehicle manufacturing and life-cycle processes. Although water use is typically metered at the factory level, water consumption (i.e., water lost through evaporation and/or incorporation into a material, part, and/or product) is much harder to quantify. In this paper, we will discuss the amount of water consumed directly in vehicle manufacturing and the vehicle life cycle processes. This “direct” water consumption can be directly traced to the vehicle manufacturing analogously to direct labor. It will also be shown that indirect processes, specifically, electricity production and consumption also counts for a significant amount of water consumption. Reduction of electricity consumption, in particular from thermo-electric power plants, can lead to substantial water consumption reductions, and thus win-win situations. The impact of water consumption varies by region and locality, and the impact of water saving technologies in production may be negated by increased use of electricity in water scarce regions.