Numerical Procedures and their Practical Application in PV Module Analyses. Part IV: Atmospheric Transparency Parameters - Application (original) (raw)
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American Journal of Modern Physics, 2020
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Effects of solar irradiation conditions on the outdoor performance of photovoltaic modules
Optics Communications, 1998
Energetic losses, relative to the standard conditions of testing, in photovoltaic modules in outdoor operation, were Ž. analyzed and the role of the optical effects is discussed. The following four loss effects were estimated: a reflection of Ž. Ž. Ž. unpolarized light, b spectrum, c intensity of the light and d temperature of the module. Four independent models were used to describe these four losses. The models were validated by the experimental data of an outdoor measurement campaign performed on 08 tilted modules at 418N latitude in South Italy. Disagreement reaching 5% under clear sky conditions was found between theoretical predictions and experimental data for the instantaneous total loss. As a result of a critical analysis of the literature data on this subject, it could be explained by invoking the presence of a fifth loss mechanism: the polarization of the incident light. Final relative losses, due to the particular state of the incident sunlight, amount to about 7-8% of a total of 14-15%. Of these, 3% is due to the low irradiation level, 1-2% to the polarization of the skylight and Ž. 3% to the reflection of the incident light on the front cover of the module. The spectral effects are negligible less than 1%. The remaining 7% loss is due to temperature effects on the module. All the loss data are reported as a function of the air Ž. mass AM. The maximum operating efficiency is reached at AM f 1.5.
The paper deals with an extensive PV modules monitoring activity carried out at the outdoor station ESTER of the University of Rome Tor Vergata. The purpose of the work was to evaluate and compare the performances of PV silicon modules of polycrystalline and amorphous technologies during a medium term outdoor exposure at optimized tilt angle, facing south. Two PV modules, one polycrystalline by Kyocera and one double junction amorphous by EPV Solar have been exposed since May 2009. A complete characterization of the weather conditions at the site during the test has been performed and the most relevant parameters for the performance comparison of the two technologies have been derived. In order to compare different technologies and power productions, the energy Yield (Y) and Performance Ratio (PR) for the two modules have been evaluated on a monthly and yearly basis. The typical seasonal trend of PR has been observed for the polycrystalline module, essentially due to the temperature influence on the module performances. For the EPV module, instead, a degradation trend has been observed for the first months of operation. Subsequently a significant recovery in the PR and energy production has been registered.