2.1.1. Geometric model
To develop the STSC model, we propose the integration of the geometric model, which corresponds to the intercept of a circular area with a virtual parabola, as shown in Fig. 2. In this geometrical model, it is necessary to specify the height of the virtual parabola, the coordinates of the centre of the circular area and the radius. This model moves the intercept point along the y-axis, which can be applied to parabolic concentrators, shifting the intercept point to the origin. The limits of the reflector are given on the y-axis and are delimited by (yint ± r). Finally, the black-shaded section represents the differential area increase or the reflector segment, which corresponds to the area under the normal distribution curve of the solar image (i.e., the focal point).