Bifacial NICE Modules from High Efficiency n-type BiSoN Solar Cells

Abstract This paper summarizes results from bifacial glass/glass NICE modules, using n-type BiSoN solar cells with efficiencies in the 20.0% range. A first series of industrial size (Sixty 156x156mm2) modules, fabricated under non-ideal conditions, exhibit a typical power of 250Wp under front illumination at STC conditions. Two modules have been installed and monitored at the ISC-Konstanz test site in El Gouna Egypt (27°N latitude). Monitoring data from the outdoor performance of these modules between the beginning of 2014 and August 2014 are analysed and compared to the data of a standard mono-facial reference module with an STC power of 255W. The bifacial modules show an average gain in generated power of 14.3% compared to the standard mono-facial reference module. During this monitoring period instantaneous effective peak powers of 313W were observed for the bifacial modules due to reflection from the ground in addition to the front illumination of the modules. Since bifacial modules produce high currents under bifacial operation, the current rating of standard junction boxes can become a critical factor. In this paper a newly developed junction box with a maximum current of 20A and a rated current of 17A is introduced.