Electric or pneumatic? Comparing electric and pneumatic linear drives with regard to energy efficiency and costs
Linear drives are broadly used in industrial automation, e.g. for material handling systems, assembly lines or machine tools. In many applications, both compressed-air powered pneumatic drives as well as linear electric drives can be used. The use of compressed air is generally associated with comparatively low energy efficiency. This has triggered a debate about the energy-related performance of alternative drive systems. In this paper, we contribute to this debate by providing insights into the energy efficiency and costs of pneumatic and electric linear drives. For this purpose, we introduce and apply a simple framework for comparing these two types of drives. Within this framework, we systematically analyze the impact of varying framework conditions on the comparison and we show how variations of these conditions affect the results. Our findings underline that electric linear drives tend to be more energy-efficient and less expensive under certain conditions while in other cases, the opposite is true. Thus, general statements about the energy efficiency and costs of pneumatic and electric linear drives can be misleading. While our results allow identifying general trends, a case-based in-depth analysis is advisable to determine which linear drive technology is most suitable for a specific application.