Implementation of the IEC TS 60904-1-2 Measurement Methods for Bifacial Silicon PV Devices

Bifacial crystalline Silicon (Si) photovoltaic (PV) devices are attracting considerable interest from manufacturers and the market since they can enhance the performance in comparison with traditional monofacial PV devices. Technical specification IEC TS 60904-1-2 was published in 2019 and proposes several characterization methods for bifacial PV device testing based on single-side, double-sided and natural sunlight illumination. This article analyses the advantages, disadvantages, the suitability and the feasibility of the different methods and compares the electrical performance obtained by the proposed approaches at the European Solar Test Installation for the testing of bifacial Si devices. Deviations in Pmax below 0.9% for the different testing methods under test was obtained except for the double-source approach with a rear reflector (2.59%) where the measurement of the rear irradaince influence the P max.