Current Trends and Innovations in Enhancing the Aerodynamic Performance of Small-Scale, Horizontal Axis Wind Turbines: A Review

Abstract

Wind energy has proven to be one of the most promising resources to meet the challenges of rising clean energy demand and mitigate environmental pollution. The global new installation of wind turbines in 2022 was 77.6 GW, bringing the total installed capacity to 906 GW, documenting an astounding 9% growth in just one year (Lee and Zhao, 2023, Global Wind Report, GWEC. Global Wind Energy Council). Sizeable research continues to focus on improving wind energy conversion, safety, and capacity. However, funding allocations and research have not matched this sustained market growth observed over the last few decades. This is particularly the case for small-size wind turbines. We define small-scale wind turbines as those with an output power of 40 kW or less that can nonetheless be interconnected to provide larger power output. Thus, the paper focuses on small-scale horizontal-axis wind turbines (HAWT) with emphasis on current technology trends including data gathering, aerodynamic performance analysis of airfoils and rotors, as well as computational approaches. The paper also highlights the challenges associated with small-scale HAWTs thereby conjecturing about future research directions on the subject. The literature review suggests that small-scale HAWT wind turbines are suitable for harnessing energy in communities with limited resources where grid-supplied power is out of reach. The power coefficient of these turbines ranges from 0.2 to 0.45 which shows that it could greatly benefit from research, built on targeting these modest performance scales by using efficient airfoils, mixed airfoils, optimizing the blade geometry, shrouding the wind turbine rotor, using maximum power tracking control, etc. This review paper is an attempt to prioritize and layout strategies toward evaluating and enhancing the aerodynamic performance of small-scale HAWTs.