This paper explores energy harvesting techniques applicable to Internet of Things (IoT) devices, focusing on renewable energy sources such as solar, thermal, and kinetic energy. The study reviews current technologies and their efficiencies, presenting a comparative analysis of different energy harvesting methods. Experimental results demonstrate the feasibility of integrating these techniques into low-power IoT applications, potentially extending the operational life of devices without the need for frequent battery replacements. The research underscores the importance of sustainable energy solutions in the IoT landscape.