Power rating procedure of hybrid concentrator/flat-plate photovoltaic bifacial modules

Hybrid concentrator/flat plate photovoltaic (CPV/PV) technology combines III-V multi-junction and flat plate bifacial solar cells to convert direct, diffuse and rear irradiance into electricity. For the first time, this article presents a procedure to rate the power output of such modules at standard test and standard operating conditions. The reference conditions, data filtering criteria and translation methods are taken, and in some parts adapted, from the CPV, flat plate PV and bifacial PV IEC standards. The power rating is based on outdoor measurements performed on two hybrid modules (A = 1088 cm2) equipped with III-V triple- or four-junction solar cells mounted on bifacial p-PERC c-Si cells. The results show that the modules, named triple- and four-junction EyeCon, convert the reference AM1.5g spectrum with an efficiency of 32.6 and 34.2%, respectively. This exceeds by 1.4 and 3%abs the highest value reported so far for a terrestrial module that harvests global irradiance. Additionally, the modules generate 11.5 and 10.9 W/m2 for every 100 W/m2 of rear irradiance to surpass an output of 350 W/m2. Finally, the influence of illumination mode, type of irradiance sensor and filtering criteria were evaluated and a simplified alternative with an acceptable power output underestimation of 0.5%rel is presented.