Abstract
•Solar PV energy harvesting techniques with MPPT algorithms adopted for IoT sensors/nodes.•The state of the art MPPT algorithms for ultra-low power PV energy harvesting applications are discussed in detail.•MPPT algorithm includes the hill-climbing or P&O method, fractional open-circuit voltage, time-based MPPT, and negative feedback-based MPPT.•Research issues and challenges for the designing and implementation of PV-EH-IoT are discussed.•Solar PV-EH-IoT has the potential to provide reliable energy in indoor and outdoor conditions for the continuous operation of the IoT node.•Solar PV-hybrid energy harvesters can be the alternative to bulky storage devices.
Internet of Things (IoT) is a powerful platform for connecting the physical world to the digital one. The recent development in IoT-based technologies has increased human-technology interaction and consequently improves the quality of life. Low-cost deployment, remote access, and the auto-mechanized operation of IoT nodes/sensors are attractive attributes that compel the wide adaption and mushrooming growth of IoT in environmental, health, and industrial applications. To confront the issue of energy scarcity, environmental energy harvesters (EHs) are imperative for self-powered and self-sustained IoT nodes. Indoor or outdoor light energy scavenging by PV panels is widely adopted for EH-IoT, as it is a source of higher energy density. Significant research efforts are required to deeply investigate the pros and cons of solar PV energy harvesters (PV-EH) towards self-sustainability goals. This study presents a comprehensive review of recent developments, comparative analysis of solar PV-EH, and algorithms for self-powered, self-sustained IoT nodes. The maximum power point tracking (MPPT) techniques for PV-EH-IoT are briefly elaborated and a concise summary of employed MPPT algorithm, converter type, input/output parameters, storage devices, as well as fabrication technology and power efficiency are presented in tabular form. Furthermore, the commercially available devices and integrated circuits (ICs) for ultra-low power solar PV-EH-IoT are introduced. Finally, the research issues and challenges in the development of PV-EH-IoT are presented. The outcome of this article includes a better understanding of current trends and progress in PV-EH-IoT focusing on MPPT techniques, challenges, and issues in the development.