Abstract
The rapid expansion of the bifacial photovoltaic (PV) market requires reliable characterization methods. However, current technical standards primarily provide detailed guidance for indoor testing, leaving a gap regarding systematic and repeatable outdoor procedures. This paper addresses this lack by proposing a structured three-phase experimental outdoor protocol for the full characterization of bifacial PV modules. The procedure is specifically designed to enable facilities lacking indoor solar simulators or climate-controlled environments to accurately extract electrical and metrological parameters under real operating conditions while maintaining alignment with the existing normative framework. The proposed protocol is organized in three phases: an acceptance phase for the determination of electrical parameters (VOC, ISC, PMAX, IMAX, VMAX), bifaciality (φ), and fill factor (FF) translated to Standard Test Conditions (STC) and Bifacial Standard Test Conditions (BSTC); the determination of temperature coefficients for ISC, VOC, and PMAX via controlled temperature ramps; the measurement of the rear-irradiance-driven power gain yield (BiFi). The methodology was experimentally validated on 13 custom-made Mono-PERC bifacial modules designed for agrivoltaic applications. Results demonstrate that the obtained parameters are fully comparable to manufacturer specifications, confirming the protocol’s robustness for datasheet validation. The discussion analyzes the intrinsic challenges of outdoor parameter determination, in particular for the ISC temperature coefficient, and suggests a possible linear relationship between the BiFi parameter, nominal power, and the rear active surface of the modules. The main contribution of this work is the definition of a structured, repeatable outdoor testing protocol that can be adopted by laboratories lacking indoor characterization facilities.