This International standard constitutes a guide and gives an overview of terrestrial PV power generating systems and the functional elements of such systems, as shown in figure 1. Systems and the functional elements of such systems, as described in this guide, should serve as an introduction to future IEC PV system standards under consideration. This standard contains: - an overview of major sub-systems - a functional description of major components and interfaces (figure 1) - a table with possible configurations which can be derived from the layout in figure 2.