By now, the increasing in energy demand, the decrease of fossil resources and the environmental and climate problems caused by these fossil resources are the mains challenges of the researchers. To overcome this issues it is necessary to develop optimized and sustainable energy systems.The Compressed Air Energy Storage (CAES) and the development of Net Zero Building (Net ZEB) appear as an appropriate solution for island area with a tropical climate and no connected electric grid as Reunion island.The modelisation of a compressed Air Energy Storage system connected photovoltaic generator (PV), a building and the grid will be the main subject of this study.