**4. Experimental work**

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

**131**

**Table 1.**

Maximum reverse current

*Electrical characteristics of both PV modules.*

*Influence of the Incidence Angle Modifier and Radiation as a Function of the Module…*

incidence effect is measured with the short circuit current which is assumed to be proportional to the light reaching the solar cell and thus the photon generation.

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.

the IAM of solar cells and whole modules, see **Figure 5**.

**4.2 Global and direct irradiation**

Diffuse solar radiation (Gb). Direct beam solar radiation (Gd).

diffuse radiation.

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

Global solar radiation on horizontal surfaces can be measured with a pyrometer or reference cell which is an instrument that measures global solar radiation from all directions. To calculatee the global solar radiation we use the formulate as follows.

Solar radiation on a horizontal surface is the sum of the horizontal direct and

G = G + G Hdb

The solar module is irradiated by permanently changing solar spectrum. To nevertheless be able to compare the performance of different solar cells technology,

/ ^2 115,3 Irradiance

Power (Pmax) 240 Open circuit voltage (Voc) 36,72 Short circuit current (Isc) 8,74 Voltage at maximum power (Vmp) 28,89 Current at maximum power (Imp) 8,31 Permissible system voltage 1000VDC

Application class A

[ ] [ ]

*W m* (1)

1000 / ^2 <sup>∗</sup> <sup>=</sup> *Avarage value W m mV*

a standard spectrum with a relative air mass (AM) of 1.5 was defined:

*DOI: http://dx.doi.org/10.5772/intechopen.96160*

**4.1 Isotextured solar cell**

incidence effect is measured with the short circuit current which is assumed to be proportional to the light reaching the solar cell and thus the photon generation.
