Since people are worried about the environment and energy costs, several governments have chosen to concentrate on renewable sources in their new energy strategies. Renewable energy sources are capable of being widely used and are environmentally sustainable. Examples of these are wind, solar, and hydro power. In comparison to standalone systems, hybrid systems provide a more affordable, sustainable, and stable power supply under various load demand situations by integrating these renewable energy sources with backup units. An essential element of these hybrid systems entails adjusting the dimensions of components to guarantee they satisfy load requirements while minimizing investment and operational expenses. Amid the extensive acceptance of renewable energy sources, several research have surfaced that concentrate on refining and determining the appropriate scale of hybrid renewable energy systems. This research conducts a thorough examination of current optimal sizing methods discussed in existing literature. The objective is to contribute significantly to the wider incorporation of renewable energy by improving economic feasibility and system suitability.