State-of-the-art review of micro to small-scale wind energy harvesting technologies for building integration

The utilisation of wind power in buildings has gained significant interest, but deploying wind turbines in built environments presents unique challenges due to highly turbulent wind patterns. Existing small wind turbines may not be as efficient in such complex conditions, and their transient loads and vibrations can compromise their durability. This study aims to assess the recent status, challenges, and limitations of building-integrated wind turbines and micro or small-scale wind-induced vibration technologies to enhance their performance, efficiency, reliability, and cost-effectiveness. The research evaluates advancements, applications, and technical features that optimise these technologies to function effectively in non-uniform wind flows and a wide range of wind speeds. Modeling conventional systems, including horizontal axis and vertical axis wind turbines, is well-established using computational fluid dynamics and blade element momentum methods. Micro or small-scale windinduced vibration technologies have demonstrated power outputs ranging from milliwatts to kilowatts, making them suitable for powering actuators and low-powered sensors used in buildings. The study emphasises the importance of harnessing wind velocity acceleration induced by the building's roof shape when incorporating wind energy harvesting technologies. Nevertheless, research on wind-induced vibration harvesting primarily takes place in controlled environments, neglecting the influence of real buildings. This represents a significant research gap, considering the potential for wind-induced vibration technologies to provide power to off-grid communities and facilitate building integration. The lack of comprehensive analysis concerning the energy, economic, and environmental aspects of micro-energy harvesting technologies hinder their widespread adoption and a comprehensive understanding of their potential. Addressing these research gaps is essential to promote the implementation and efficacy of micro-scale wind energy harvesting technologies in various real-world scenarios.