Morteza Ahangari Hassas - Department of Electrical Engineering , East Azarbaijan Science and Research Branch, Islamic Azad University,Tabriz, Iran,
Kazem Pourhossein - Department of Electrical Engineering ,Tabriz Branch, Islamic Azad University,Tabriz, Iran

Hybrid renewable energy systems are suitable alternatives for single-source renewable energy systems due to intermittent nature of most of them. One of the most important issues related to hybrid renewable energy systems is to find the optimal size for the system for its efficient techno-economic operation. There are several methods for optimal sizing of hybrid renewable energy systems and each of the sizing methodologies, has its specific features but undoubtedly, hybrid methods or in other words multi objective methods, provide the most ability among the various sizing methodologies. In this paper, in addition to various sizing methodologies have been categorized, an attempt has been made to present a comprehensive review of the multi objective methods, because the hybrid methods are the most versatile.

Hybrid system, multi objective methods, optimal sizing, renewable energy