Darrieus

Darrieus refers to a type of vertical axis wind turbine (VAWT) invented by Georges Jean Marie Darrieus in 1931. The defining characteristic of a Darrieus turbine is its rotor, which consists of three or more airfoil blades attached to a central rotating shaft. These blades are typically curved or straight and are arranged in a cycloidal or helical pattern. The lift forces generated by the rotating airfoils, rather than direct wind pressure, cause the rotor to spin.

Darrieus turbines are known for their ability to operate independently of wind direction, meaning they do not require complex yaw mechanisms to orient themselves into the wind. This can simplify their design and maintenance. They are generally considered to be more efficient at converting wind energy into mechanical energy than other VAWT designs at higher wind speeds. However, they often require an external power source or a starting mechanism to begin rotation, especially at low wind speeds, as they cannot self-start effectively.

The design has seen several variations and improvements since its inception, including the Giromill, which uses straight blades, and the eggbeater design, which uses curved blades. While Darrieus turbines offer advantages in certain applications, such as urban environments or offshore installations where wind direction can be variable, they have historically faced competition from more prevalent horizontal axis wind turbines (HAWTs) due to factors like higher manufacturing costs and some challenges with structural fatigue. Nevertheless, research and development continue to explore their potential.