In pneumatic systems the consumption of electrical energy depends almost linearly on the production of compressed air. Hence, the operation of the pneumatic line in any application plant has an enormous effect on the overall energy efficiency. In analysis the compressed air system can be divided into three subsystems: production, after treatment (storage and transmission) and consumption. These systems interact with each other and strongly affect overall system energy requirements. Starting from the dynamical models of the subsystems a new generic energy efficiency index (CA-index) is introduced in the paper. It can be used both in one compressor and multi-compressor systems. The fact that the consumption of compressed air may be either pressure dependent or pressure independent is taken into account in the basic equations and in the energy efficiency index. The maximization of the index is carried out by defining and solving a mathematical optimization problem, which then gives the best possible operation policy of the pneumatic line.

Keywords: compressor, energy efficiency, CA index, pneumatic systems, compressed air, dynamic model, optimization