Global efficiency of an UPS module integrated with PV, H2, and CAES systems

In this paper the efficiency of a complex plant that serves as Uninterruptible Power Supply (UPS) System for road tunnel service (lighting and air circulation) is evaluated by means of an algorithm which is based on Graph Theory. Such algorithm is able to handle complex systems, even those which have energy circulation, provided that it is possible to identify the power flows, and their corresponding partitions, between the single process stations. The UPS system is composed of systems for energy production and storage, among which a Compressed Air Energy Storage (CAES) plant, Photovoltaic Field (PV), Hydrogen Cells (H2). The new code has been developed in an algebraic manipulation programming environment and so the solution is available either in numerical or in closed-form symbolic expression.