Energy Harvesting Techniques for Self-Powered Sensor Networks
Wireless Sensor Networks (WSNs) are extensively used in environmental monitoring, healthcare, industrial automation, military surveillance, and smart infrastructure. However, the limited battery life of sensor nodes restricts their long-term operation, particularly in remote areas where battery replacement is difficult and expensive. Energy harvesting offers a sustainable solution by converting ambient energy sources such as solar, thermal, vibration, wind, and radio frequency (RF) energy into electrical power for sensor nodes. This study reviews various energy harvesting techniques, their operating principles, advantages, limitations, and suitability for WSN applications. It also highlights the importance of integrating energy harvesters with energy storage devices and power management systems to ensure reliable operation. A framework involving energy source assessment, harvesting module selection, power conditioning, storage management, and adaptive duty-cycle control is presented to optimize energy utilization. Results indicate that solar energy provides the highest power output under favorable conditions, while vibration and RF harvesting are effective in indoor and industrial environments. Hybrid energy harvesting systems offer greater reliability by combining multiple energy sources. Overall, energy harvesting enhances network lifetime, reduces maintenance costs, and enables sustainable, self-powered WSNs, making it a key technology for future Internet of Things (IoT) and smart environment applications.