**4.1 Isotextured solar cell**

*Solar Cells - Theory, Materials and Recent Advances*

of an east–west oriented single-axis tracking panel was done by [16] claimed the performance of a single axis tracking, the system consist of a panel fixed in a horizontal axis, in different time of the year. They compared the gain in an est-west to north-sud. The results show that the yearly gains obtained in est-west is less than the north-sud. The results show that, the correlation between the irradiation and the latitude is hight, it's 12% at the equator and 14,3% in the Arctic. To increase the efficiencies of the PV plant, a ray tracking is performed; besides, the change of the angle may have an impact of the output of the system. The mathematical formula can accurately investigate the optical performance, As make a use by [11] with a single axis in South–North, they estimate the annual radiation of the panels composed the system when using a single axis. Some of study haves been done in china, they compare single axis and dual axis and conclude that the dual axis performed 96–97% higher than the single axis. The results illustrate that in some areas, at low resources, the tracking is unsuitable. The sun tracking may perform better than the traditional fixed if both are compared over the year, the gain performance were estimated to higher than 30% with high solar irradiation, however it is less than 20% in low

*Solar tracking system at the Cologne University of Applied Sciences.*

The outdoor system are developed and investigated. It's installed on the roof of the Technical university of Cologne. The angle of incidence starting position with orientation to the sun gradually changing the angle of inclination at a constant azimuth angle up to an angle of incidence of 90 selection of the distances between the approached angles of incidence helicopter measurement horizontal module storage (inclination = 90°) gradual change in solar tracker azimuth orientation over a total angle of 180 choice of the distance between the approached angles. The angular

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irradiation areas [17–19].

**Figure 5.**

**4. Experimental work**

The incident angle modifier is varied for 0° to 90°. The measurement of the short circuit current of the two modules is done when the incidence angle is changing. A textured surface retains more light than a plane surface in a active area of a PV or cell. However, the advantage of the rough surface can be offset by the mechanism of the recombination at the surface of the PV module or cell textured. At the comparably low angles of incidence, the reflection is reduced to 4% [20]. A textured such as the Alberino glass will drastically lower the reflection for angles of incidence ≥50° and thus will keep the incidence angle midifier closer to unity. The texture of Alberino P is the best described as inverted and rounded pyramid. The **Table 1** shows the electrical characteristics of the Two PV plants in monocrystalline silicone.

Within the framework of this work a solar tracking device was constructed at the Cologne University of Applied Sciences (CUAS) which is capable of measuring the IAM of solar cells and whole modules, see **Figure 5**.
