Hybrid power systems are one of the most advanced and future-proof power systems in research. Over the past few years, a lot of research has been done on the design, optimization, operation and management of renewable hybrid energy systems. It is clear that this field is still developing and has a large scope for reach. In a hybrid power system, energy generated from non-conventional energy such as wind, solar energy, etc. and energy generated from conventional energy such as a diesel generator are stored in batteries that serve as a power source. In hybrid mode, small wind turbines, photovoltaic systems and diesel generators are connected to the battery. These systems are connected with remote and off-grid locations, which is called a hybrid power system. In terms of cost, efficiency, and dependability, a combination of two or more renewable energy sources is more effective than a single source. This is referred to as a Hybrid Renewable Energy System (HRES) and it is a rapidly growing industry on a global scale. In this review paper, the latest developments in research on modeling hybrid energy resources (wind, PV systems, etc.), backup power systems (fuel cells, batteries, supercapacitors or ultracapacitors, diesel generators, etc.), power conditioning units (MPPT converters, buck / boost converters, battery chargers, etc.), as well as detailed methodologies for managing energy flows are discussed.