Energy efficiency optimizes energy use in a specific product, process, or consumption without compromising output, or comfort levels. As an integral component of energy conservation policies, it aims to reduce energy intensity, preserve resources, and mitigate environmental impact by reducing CO2 carbon dioxide emissions, optimizing energy use, and minimizing waste. In industrial processes, energy losses occur in exhaust gases or effluents released at various temperature levels. Despite ongoing efforts to mitigate these losses, economic considerations frequently constrain such endeavors. However, adopting various waste heat recovery technologies, like steam generators, is an avenue for capturing and reutilizing lost energy, particularly associated with exhaust gases. This can be done through energy audit methodology to identify inefficiencies and recommend appropriate waste heat recovery technologies to optimize boiler performance and environmental outcomes. This study aims to present the state of the performance of the steam generator in thermal power plants to enhance energy efficiency. explore various sources of heat loss and inefficiencies within boiler systems, examining the percentage contributions of different heat loss mechanisms, using energy auditing methods.