Waste-to-Energy (WtE) thermal power plants offer a sustainable solution for simultaneous municipal solid waste (MSW) management and electricity generation. This study presents a detailed performance and environmental assessment of a WtE thermal power plant operating under varying load conditions. Key performance indicators, including thermal efficiency, heat rate, and specific carbon dioxide (CO₂) emissions, were analyzed to evaluate the influence of operating load on plant performance. The results demonstrate a clear improvement at higher loads, with increased thermal efficiency, reduced heat rate, and lower specific CO₂ emissions per unit of electricity generated. These enhancements are attributed to improved combustion stability, effective utilization of the calorific value of MSW, and lower relative auxiliary power consumption. The analysis confirms that operation near rated capacity maximizes energy recovery and minimizes environmental impact, highlighting the importance of consistent waste supply and optimized load management. Beyond technical performance, the study underscores the role of WtE plants in sustainable urban infrastructure by reducing landfill dependence, recovering energy, and mitigating greenhouse gas emissions. The findings provide practical insights for policymakers, urban planners, and plant operators, supporting the integration of WtE systems into modern energy strategies and environmentally responsible waste management frameworks.