Renewable Energy Power Supply Scheme for Wireless Network Nodes: A Comprehensive Survey

As a key enabler of the Internet of Things (IoT), wireless sensor networks (WSNs) are widely deployed in environmental monitoring, smart cities, and industrial systems. However, conventional battery-powered operation is limited by finite lifetime, high maintenance cost, and environmental concerns, thereby restricting large-scale and long-term deployments. Renewable energy harvesting offers a promising alternative, yet its practical adoption is fundamentally constrained by the mismatch between stochastic energy supply and dynamic workload demand. This survey provides a comprehensive review of power supply solutions based on renewable energy for WSN nodes, including solar, mechanical, emerging, and hybrid energy harvesting technologies. A scale-aware evaluation framework is developed based on three dimensions: energy supply capability, environmental adaptability/source availability, and hardware reliability, enabling more consistent interpretation across technologies without directly ranking technologies according to absolute harvested power. Based on this framework, representative technologies are analyzed in terms of their operating principles, output characteristics, and deployment suitability under diverse conditions. Furthermore, a cross-layer analytical perspective is adopted to connect device-level energy harvesting, circuit-level power conditioning and load-side usable energy delivery, and network-level performance. Deployment-oriented design considerations and system-level workflows are also examined to support practical WSN implementations. Overall, renewable-energy-based power supply technologies provide a viable pathway toward sustainable, long-lived, low-maintenance WSN operation. Addressing the energy supply–demand mismatch is essential for achieving scalable and energy-autonomous WSNs in future IoT deployments.