Solar-based and battery-assisted energy harvesting systems for IoT: A systematic survey

Solar energy harvesting combined with battery storage is a key enabler for achieving longterm autonomy in Internet of Things (IoT) systems. However, existing research remains fragmented across heterogeneous hardware design strategies, energy-management techniques, and applications spanning a wide range of domains, often addressing isolated technical aspects without providing a comprehensive system-level perspective. Following the PRISMA guidelines, this systematic survey synthesizes 25 primary studies selected from an initial corpus of 357 publications on solar-based, battery-assisted Energy Harvesting Systems (EHS) for IoT. The review examines four complementary dimensions: hardware architectures, energy-aware hardware and software strategies, deployment domains, and reported performance outcomes together with their associated limitations and challenges. The analysis reveals persistent open issues related to solar intermittency, resource-constrained IoT devices, long-term autonomous operation, environmental reliability, and the lack of standardized design and benchmarking frameworks. Based on these findings, the survey identifies key methodological and technological research gaps and discusses future directions toward more self-sustainable solar-powered IoT nodes. To the best of our knowledge, this is the first PRISMA-compliant systematic survey that provides a holistic synthesis of hardware architectures, energy-management strategies, application-domain requirements, and benchmarking and reproducibility challenges in solar-based, battery-assisted IoT EHS.