20th –EU-PVSEC, Barcelona, Spain, 6-10 Jun 2005 STRAIGHT FORWARD TECHNIQUE FOR SIZING STAND-ALONE PV HYBRID SYSTEMS

The main purpose of this paper is to introduce a simple but effective technique for sizing stand-alone PV hybrid systems. Most of the available sizing methods and software-tools require lots of data on energy resources, demand and system technical specifications. Owing to the complexity of this topic, the presented sizing technique needs only very little information about the application of interest and location. It proceeds in practical and plausible steps to design the rated powers of the desired components (e.g. the peak power of the PV plant, inverter, battery, bidirectional battery inverter and diesel generator). An energy balance equation for estimating the required daily PV energy is developed in this work. This equation integrates several characteristic parameters (e.g. solar fraction, solarload-mismatching factor and conversion efficiencies). In this way, it can be adapted to user requirements, components characteristics and the technical specifications of the system components. Based on a case study, the necessary knowledge for the implementation of this technique and several helpful sizing curves are introduced.