According to the operation principle mentioned above, the air inside a system is less dense than the atmospheric air outside. The air moves in and out of the solar chimney system continuously, driven by the pressure difference between the inside and outside. This pressure difference will be called the available driving pressure and symbolized as Δptot. Neglecting friction losses [17], Δptot can be subdivided into a turbine extraction component representing the pressure extracted at the turbine, and a dynamic component describing the kinetic energy of the airflow