ABSTRACT
There are several different design concepts for wind turbines. One basic classification is Horizontal Axis Wind Turbines (HAWT) versus Vertical Axis Wind Turbines (VAWT). Horizontal Axis Wind Turbines can have the rotor upwind, that is facing the wind or downwind so that the wind will pass the tower and nacelle before it hits the rotor (see Figure 7.1). Today most turbines have an upwind rotor, but there are turbines, from prototypes in the MW-class to smaller turbines with a nominal power of 20–150kW, as well as water pumping wind wheels from the 19th century, with downwind rotors. Types of wind turbines https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315781396/7bd2c24d-ec9d-41f6-8ef7-d67b9d596187/content/fig7_1_B.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Source: Tore Wizelius
