Autonomous smart vertical farming: A systems-level synthesis of IoT and solar energy integration for sustainable agriculture

Rapid urbanization, land degradation, and climate variability are increasingly constraining food production, especially in densely populated urban regions. Vertical farming (VF), which grows crops in stacked layers under controlled conditions, is gaining recognition as a potential solution for sustainable urban agriculture. However, high energy requirements and questions surrounding long-term resource efficiency continue to challenge its scalability and environmental viability. This review explores the potential of smart vertical farming (SVF) systems, enhanced by the Internet of Things (IoT), wireless sensor networks (WSNs), and hybrid green energy-harvesting systems such as photovoltaic (PV) and thermoelectric (TE) technologies. This research analyzes how real-time data-driven control of lighting, climate, irrigation, and nutrient delivery, combined with renewable energy solutions, can improve the environmental performance and autonomy of SVF systems. The article synthesizes recent literature on hydroponic production, smart sensing, energy optimization, and automation, with a specific focus on resource use efficiency, including water, energy, and land inputs. Global case studies are compared to highlight both technological advancements and context-specific challenges, particularly those relevant to low-resource or climate-vulnerable settings. This paper fills an important void in the current literature. Specifically, it provides a high-quality study of how collaborative design can combine IoT and hybrid renewable energy-harvesting systems to enhance energy autonomy, scalability, and environmental performance in smart vertical farming (SVF). Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-guided review methodology, this paper synthesized information on hybrid photovoltaic-thermoelectric generator (PV-TEG), WSN, and data-driven automation technologies by reviewing recent (2015–2025) experimental, modeling, and pilot-scale studies. The analyses have shown that all of these hybrid energy-harvesting configurations provide greater resilience and increased uptime compared to single-source systems. According to the analysis, hybrid energy-harvesting topologies can increase operational resilience in the face of changing environmental conditions and increase system uptime by 15–35% compared to single-source systems. The findings of this review provide a rich source of actionable design ideas, along with a comprehensive examination of region-specific obstacles and research gaps towards developing low-carbon, climate-resilient urban food production systems.