Characterizing state-of-the-art solar panels a new approach for large area testing

Modern multi-junction and thin film cells show transient effects when characterized by means of flash lamp testers. This paper reports on a new characterization method using a system driven by a 200 kW high-pressure arc lamp. The lamp can be operated in either long-pulse or continuous mode and illuminates targets of up to 12 m² with a uniformity of ±2%. It is shown that by means of special thin film filters the emitted lamp spectrum is a close match to AM0. Furthermore a new approach of acquiring the solar cell/panel I-V-curve data has been developed that holds the load voltage constant at defined points across an I-V-scan, and slightly modulates the panel current by modulating the irradiation intensity. Panel current and voltage are analyzed based on irradiation level and the correct I-V-curve is derived. The I-V-data acquisition system also allows characterization of transient cell and panel effects. Experiments demonstrate that the VLASS system together with its data acquisition system can be used to characterize entire solar string/panel capacitance values