Advancements in low-speed wind turbines: A short review

In recent years, interest in low-speed wind turbines has grown as a promising solution for harnessing wind energy in regions with low, fluctuating wind speeds (<5 m/s). Numerous studies have focused on improving the aerodynamic performance, self-startability, and operational stability of these turbines through the development of hybrid designs and various enhancement technologies. This article critically reviews recent advancements in low-speed wind turbine technologies, focusing on vertical-axis turbines, hybrid systems, and bladeless turbines, and assesses their performance and practical applicability. The results show that Savonius and Darius turbines are the most commonly used, with power factors ranging from 0.15 to 0.30 for Savonius turbines and from 0.30 to 0.45 for Darius turbines. However, the latter requires higher starting speeds (>3 m/s). Hybrid systems achieved performance improvements of 10–25 % due to enhanced starting characteristics and aerodynamic behavior, while bladeless turbines operated at very low speeds (<2 m/s) but suffered reduced efficiency. Critical analysis revealed significant variation in reported improvement rates across operating conditions, turbine size, and test type, as well as the absence of a standardised performance evaluation framework. Research gaps also persist due to a scarcity of large-scale applied studies and weak economic analysis. Therefore, this study recommends a future focus on developing standardised measurement criteria, conducting long-term field trials, and integrating advanced modelling and economic analysis to enhance the practical application of these systems, particularly in developing regions.