**1. Introduction**

The conversion of solar energy in solar modules is subject to electrical and optical losses [1, 2]. Optical losses are substantially depending on light incidence angle relative to the module plane. Manufactures information of photovoltaic panels typically provide electrical parameters at only one operating condition. Photovoltaic panels operate over a large range of conditions so the manufacturer information is not sufficient to determine overall performance. The electrical power output from a photovoltaic panel depends on the solar incidence irradiation, the cell temperature, the solar incidence angle [1, 3, 4]. To minimize reflection losses and thus maximize

the electric yield, the PV industry introduced several different concepts and materials, such as antireflective coatings or structured glass with inverted pyramids [5]. To measure the nominal power, the incidence angle at normal incidence in standard test conditions is allowed. In real conditions, modules are exposed in different environments conditions. In some location, the main losses mechanism performance of PV or a system of PV is that the angle dependence. The PV module characteristics can help the company to predict accurately the PV performance. A new standard for performance testing and energy rating is under development [6]. The angle dependence losse of a PV module or a cell can be measured in several manner such the angle dependence reflectance. While reflectance measurements do not account for absorption losses, common I – V curve measurements can suffer from incorrect injection dependence and mismatch corrections.

Precise characterization methods and measurement systems are needed to assess angular dependent module performance. The incidence angle is measure of deviation from the direct solar radiation to the PV panel surface. The incidence angle is directly involved in the determination of the radiation incident angle affects the amount of solar radiation transmitted through the projective cover and converted to electricity by the cell [3, 7]. Significant effects of inclination occur at incidence angles greater than 65 degree [8]. The main of this paper is to evaluate and a comparative study of two crystalline silicone technologies in reel outdoor pyramidal textured and non-textured for different incidence angles and spectral radiation. The major difference between outdoor operation in natural sunlight and the laboratory test conditions is the existence of diffuse light, which is dependent on the climatic conditions on the location.
