A review of the current automotive manufacturing practice from an energy perspective

The automotive industry is facing on-going challenges to improve the sustainability of its manufacturing processes and vehicle emissions due to economic, environmental, marketability and policy concerns. This review aims to evaluate steps that could be taken by automotive manufacturers to further reduce energy consumed during manufacturing processes, particularly focusing on thermal management of low-temperature heat sources that are extensively present in the whole plant and in the paint shop. Through an extensive literature review on the subject, this article presents vehicle production processes, the past and future drivers, and strategies towards sustainability. Firstly, the whole vehicle manufacturing process is explained focusing on the energy sources and their use in the plant. Then, the paint shop is described as being responsible for the highest energy consumption in the production process, focusing on components, paints and energy utilisation. After presenting the practice performed by automotive manufacturers to reduce the energy consumption of their production process in terms of energy efficiency and thermal management, the article is closed by future steps that could be undertaken by the automotive industry towards the realisation of a low-carbon sector. It is concluded that unexploited potential for heat recovery in the paint shop is present in the low-temperature range and this waste heat could be effectively exploited by liquid desiccant technology for energy consumption reduction and could increase paint quality of the painting process due to more efficient moisture control.