| Work Detail |
The European Unions Joint Research Centre (JRC) has updated the core technology of the Photovoltaic Geographic Information System (PIIS) to reflect the dominance of crystalline silicon solar technologies over thin-film solar technologies in the global energy market. A research group led by scientists at the European Commissions Joint Research Centre (JRC) in Ispra, Italy, has updated the Power Performance Model (PPM) to reflect recent developments in photovoltaic technology. The PPM is the core of the European Commissions Photovoltaic Geographic Information System (PVGIS) , a web-based application that allows users to estimate global photovoltaic production. “The original calibration of PPM coefficients for crystalline silicon (cSi) modules was reported in 2011. The coefficient values ??for copper indium diselenide (CIS) and cadmium telluride (CdTe) module technologies were reported in 2010. These have continued to be used to date, with only minor modifications,” the team noted. “However, in recent years, the photovoltaic manufacturing sector has made notable progress, both in volumes and power conversion efficiency.” To recalibrate PVGIS results based on new developments, the scientists used updated power array datasets produced by the European Solar Test Facility (ESTI). They included seven cSi samples—four with PERC technology, two with a back-contact (BC) design, and one with a heterojunction (HJT) architecture. They also included three CIS modules and two CdTe panels. “For each module, a power data matrix was measured in an indoor solar simulator according to IEC 61853-1, covering irradiances of 100, 200, 400, 600, 800, 1000 and 1,100 W/m2 and temperatures of 15 °C, 25 °C, 50 °C and 75 °C,” the scientists explained, noting that this allowed them to extract coefficients that describe how the panels’ performance changes when temperature and irradiance vary. Finally, these results were normalized using standard test conditions (STC) and then fitted to the existing PVGIS power performance model using the least squares procedure. “The results show that the PVGIS power performance model with updated coefficients can provide a good description of the power output of modern cSi modules, with a mean absolute bias error (MABE) of less than 1% in almost all cases, compared to a MABE of more than 3.5% with the current coefficients,” the academics said. “The updated coefficients allow the model to better capture the improved temperature coefficients and low-light performance.” The analysis showed that, in the case of CdTe, the MBAE of the updated models was close to 2.8%, while in the original case it was 4.9%. As for the CIS, the updated MBAE was 1.65%, compared to the original 3.7%. The calculations also showed that annual DC power production increased by between 1.8% and 4.9% compared to the current model for five of the six reference climates specified in the IEC 61853-4 standard. The only exception was the high-altitude climate, which showed a reduction in efficiency of -0.9%. The updated model was presented in “ An Updated Simplified Energy Yield Model for Recent Photovoltaic Module Technologies ,” published in Progress in Photovoltaics . Researchers from the European Commission’s Joint Research Centre (JRC) in Ispra, Italy, and the University of Göttingen in Germany contributed to the study. |
