Comparative Analysis of Design Parameters Influencing the Aerodynamic Performance of Small Horizontal-Axis Wind Turbines under Low Wind Speed Conditions: A Review

The aerodynamic performance of small horizontal-axis wind turbines (SHAWTs) operating in low-wind-speed regions is highly sensitive to design and operating parameters. This review evaluates the effects of wind speed, airfoil selection, tip speed ratio (TSR), chord length, and twist-angle distribution on the power coefficient (Cp) and total energy output. Findings from the literature show that wind-speed variation, particularly within 3–10 m/s, has the strongest influence on power generation, with performance improvements exceeding 300% because of the cubic relationship between wind speed and power. Among geometric parameters, blade twist optimization, ranging from 35° at the root to 0° at the tip, provides the greatest Cp enhancement, with reported increases of up to 26%. Combined chord–twist optimization also improves performance, whereas chord-only adjustment gives modest gains of about 2–3%. Low-Reynolds-number airfoils such as SG6043 and NACA 4412 can increase Cp by up to 15%. This supports efficient SHAWT design for low-wind-speed applications.