The incident radiation for the peak sun angle of 0° is shown in Figure 7 (above). The capturing of the targeting of
the incoming Direct Normal Irradiation towards the two receivers can clearly be seen. The insert shows how the four
absorber pipes absorb the concentrated radiation while the cavity walls reflect it. The effect of the different
refractive index of the transparent glass cover is evident in the discontinuity of the radiation contours.
As the etendue conserving mirror layout seeks to improve the optical efficiency of the mirror field, a flat
Compact Linear Fresnel model with 30 mirrors is used as the basis for comparison for both the sun tracking etendue
curve with peak sizing and the off-peak etendue conserving mirrors. A series of simulations were run and are
summarized in the total absorbed radiation [W] on all eight absorber pipes in Figure 8a) for a variation in sun angle.
The etendue conserving mirror fields can be seen to display a significant advantage over a flat mirror field