Final answer:
Lifting-style blades are more efficient in low-speed winds because they can be adjusted to maximize energy extraction, which is crucial since the power output potential is much lower at lower wind speeds.
Step-by-step explanation:
Lifting-style blades on wind turbines are designed to be more efficient in low-speed winds. These blades are like long airplane wings that can be rotated to engage the wind at any angle, which allows them to operate efficiently at various wind speeds. However, they are particularly advantageous in low-speed wind conditions because they can maximize the energy extracted from the wind by adjusting their angle of attack. This is important because the power available from the wind increases with the cube of the wind velocity, meaning that the power output potential in low-speed winds is significantly lower than in high-speed winds. Therefore, optimizing the blades to perform better in these conditions can make a substantial difference in performance.
The three-blade design is the most common modern turbine, which is capable of extracting about 50% of the energy from the wind. Its lower tip speed, compared to two or one-blade designs, makes it less dangerous and more efficient. The efficiency of a wind turbine is subject to theoretical and practical limits, such as the Betz limit and the Glauert limit, which are represented in various design curves showing optimal rotor speeds. At lower wind speeds, the design becomes even more critical to ensure sufficient power generation.