The main objective of this work is to model a renewable energy system that meets a known electric load with the combination of a photovoltaic (PV) array, a diesel generator and batteries. The replacement of conventional technologies with hydrogen technologies is examined. The analysis utilizes the power load data from an electric machinery laboratory located in Kavala town, Greece. The modeling, optimization and simulation of the proposed system were performed using HOMER software. Different combinations of PV, generators, and batteries sizes were selected in order to determine the optimal combination of the system on the basis of the Net Present Cost (NPC) method.