Since many years, engineering, research and development of hybrid systems for rural electrification are strongly supported by computer simulations. Different software packages have been used according to the required level of details along with the progress of the project HYRESS. For the development of optimal system control and load/energy management strategy, different simulation models from APL (Alternative Power Library) have been used for a Hybrid PV-wind-hydrogen system that will be installed in the Essaouira region in Morocco. This library provides models developed by IWES for the simulation of regenerative power supply systems and it is used to investigate the integration of a hydrogen storage path in hybrid system operation. Copyright (C) 2010, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.