## 5 Computational Details
Under these conditions, the distance between the tower collector and the average position in the heliostat field ranges from 21.3 m (for square heliostats with a 10\({}^{\circ}\) slope) to 22.5 m (for rectangular heliostats with a 10\({}^{\circ}\) slope). 6. Assuming that we choose a spherical curvature for the heliostats, what should the deflection be? 2 cm? 1 cm? 0.5 cm? For the sake of simplicity, we choose to use the same deflection for all heliostats, so closer heliostats produce larger, less concentrated target images (for example, in the 169-heliostat field of IMDEA Energy in Mestoles, Spain, two different curvatures were used for heliostats closer to and farther from the target [26]). We choose 1.0 cm for deflection, as in our previous work [17], as we do not want to completely focus the radiation at the target, only to slightly concentrate the radiation. With this deflection, the focal distance becomes 49.7 m for 2.0 m \(\times\) 2.0 m square heliostats and 54.8 m for rectangular 2.5 m \(\times\) 1.6 m heliostats (a detailed discussion on this topic can be found in our previous work [17]). 7. Finally, we need to set the location of the heliostat field, as latitude plays a significant role in determining the Sun's trajectory over the local site throughout the year. As in our previous works [17; 25], we selected two locations with higher and lower latitude from the list reported by SFERA III [30] for European Union CSP research infrastructures with heliostat fields: Julich, Germany (latitude = +50.9133\({}^{\circ}\), longitude = +6.3878\({}^{\circ}\)) and Protaras, Cyprus (latitude = +35.0125\({}^{\circ}\), longitude = +34.0583\({}^{\circ}\)). This 15\({}^{\circ}\) difference in latitude between the two locations is enough to produce insightful changes between the two sets of results. A second group of choices must also be considered regarding working conditions, as follows:  
1. It seems logical to scan a full year, from 1 January to 31 December, say 2024. But what should the scanning frequency be? To obtain an accurate measurement of the total mechanical rotations executed and the maximum mechanical angles achieved, the Sun position and mirror orientation calculations must be updated at least every minute, as shown below in Section 7, Results and Discussion. This can be easily achieved in these mechanical rotation studies: for each updated Sun position, the heliostats' orientation needs only to be recalculated. In the previous work [17], we chose to simulate the heliostat field conditions every hour because this frequency was sufficient to detect shading/blocking events, but also because the ray tracing simulations involved require significant computation. 2. What is the daily working range? As in our previous work, the range from 08:00 to 16:00 LCT time (i.e., Local Time [25]), which is commonly applied in CSP research facilities, was chosen. This range depends on the date and latitude, but on average, it seems a reasonable choice. Daylight Saving Time (DST) and other purely administrative or political changes to standard local time are ignored in this work. Figure 8: Layout for the simulated heliostat field, with 66 heliostats in a staggering arrangement. The target points north to collect the sun’s rays reflected. Only the 6 green heliostats are simulated. The heliostat mirrors are either square (2.0 m \(\times\) 2.0 m, separated by 1.0 m in both north–south and east–west directions), as shown in this picture, or rectangular (2.5 m east–west \(\times\) 1.6 m north–south, with 1.0 m separation east–west and 1.9 m north–south). The two central heliostats are rotated 45\({}^{\circ}\) to emphasize that they cannot touch. 3. The heliostats should start each day from the resting position and come back to this position at the end of the day (mostly to protect the heliostats from strong winds during the night). This seems to be the most reasonable option, but it increases the number of rotations that the heliostats must perform.