Mechatronics systems, by integrating mechanical, electronic, and computer technologies, offer a comprehensive solution to optimize the generation, transmission, storage, and utilization of energy, thus reducing energy waste. This paper begins by introducing the applications of mechatronics systems in renewable energy systems, encompassing the efficient capture and management of resources such as solar and wind energy to meet energy demands. Secondly, this paper discusses the critical role of mechatronics systems in smart grids, enhancing the efficiency and reliability of power systems through advanced monitoring and control technologies. Furthermore, this study emphasizes the value of mechatronics systems in designing and implementing energy-saving devices, including high-efficiency motors, intelligent lighting, and heat recovery technologies, to reduce resource wastage and environmental impact. Finally, by reducing carbon emissions and decreasing reliance on traditional energy sources, mechatronics systems actively contribute to sustainability, promoting the development of sustainable cities and buildings, and simultaneously achieving the United Nations Sustainable Development Goals.