Examination of solar cells and encapsulations of small experimental photovoltaic modules

Today´s power photovoltaic (PV) module is a complete, enclosed package of solar cells, interconnects, power leads and a transparent cover or optical concentrator, depending on the type of module. The estimated lifetime of cells used as solar converters is about 25 years. Some effects that occur on PV modules sometimes are the consequences of the encapsulant material degradation. The corrosion of conductive parts of the cells and interconnections through the encapsulant is responsible for the deterioration of the performance, e.g. changes in series and shunt resistance resulting in degradation of the PV parameters. In the paper the electrical and PV properties of small experimental modules with silicon rubber and ethylene vinyl acetate as encapsulant and the influence of ageing conditions were estimated.