Energy-saving technologies are becoming a critical component to help address the growing challenges of climate change, environmental degradation, and energy security. In this context, the integration of different sciences in physics is a fundamental approach to developing knowledge in this field. This article discusses methodological means of developing knowledge about energy-saving technologies by integrating physics with other scientific disciplines such as material science, thermodynamics, and engineering. This paper presents case studies of energy-saving technologies that use photonics, thermoelectric materials, nanotechnology, and smart energy systems to demonstrate how such methods can aid in adaptation and mitigation efforts while providing a scientific basis for sustainable technologies. Furthermore, this article outlines the critical role of interdisciplinary collaborations among scientists from different scientific disciplines in advancing research and development of sustainable energy technologies.