Reliability study of different encapsulation materials for CIGS modules

Abstract

[EN] Solar energy will become an important source of energy in the 21st century. Thin film solar cells (TF) based on CIGS technology Cu(In,Ga)Se2 are very attractive to achieve this purpose. They are not as known as the silicon ones, but their potential characteristics make them an issue to investigate and develop better technologies. Even in the last years a lot of progresses have been done, there are some critical points that must be studied. This thesis is intended to fill one of those points, study the stability of the solar modules regarding the reverse current problems. The dominant topics for CIGS solar cells covered in this thesis are (1) the problematic of the modules when they are connected in a PV system, (2) study the distribution of the temperature of the solar modules with a thermography camera, (3) try to find the origin of the distribution of the temperature, (4) find a possible solution to the reverse current problems. In this thesis is explained from the starting point the working principle in which solar modules are based, the thin film solar cells characteristics comparing in some occasion to the silicon modules, the problems generated by the reverse current in a photovoltaic system, the experiments done and the conclusions obtained. The thermal stability of the solar modules is studied by applying a current to the module and observing the behavior of it and the maximum value of the temperature that this can afford. This is measured for different types of modules, with different encapsulation materials, different resistances values or different position of the layers. This value is correlated to a PV system and helps us to determine if in a PV system there will be stability problems. It is conclude that the modules have the same distribution of the temperature even some specifications are changed in the experiments.