IMPROVEMENT OF A LED BIAS LIGHT SYSTEM FOR THE DOUBLE SIDED CHARACTERIZATION OF BIFACIAL DEVICES (original) (raw)

A double-sided solar simulator based on an existing large-area long pulse flash solar simulator and a low-cost LED-based rear bias light has been developed at European Solar Test Installation (ESTI) (Joint Research Centre, European Commission) for studying and validating the double-side indoor testing approach for current-voltage (I-V) characterization of bifacial modules. "Self-reference" methodology is applied using an accredited reference values (ISO/IEC 17025) obtained by single-side illumination. The proposed approach and prototype LED simulator for full size modules has demonstrated adequate performance in comparison with the single-side measurements based on a commercial Class AAA simulator using validated standard methodology. The electrical performance expressed in similar current-voltage (I-V) curves and power output reveals the suitability of the method for characterization of bifacial devices. The LED bias light source could be classified as a "Class C" solar simulator. The analysis of different representative bifacial PV devices available on the market shows different electrical behaviour according to their bifaciality factor.