No abstract

Photovoltaic modules can experience damages of varying severity in the case of heavy hail storms. In the worst case, complete glass and solar cell breakage results in efficiency and security losses of the affected modules which therefore have to be replaced. However, there is a strong need to inspect the remaining modules directly in the field in order to assure no hidden damage. Three hail-affected photovoltaic plants in the south of Austria were investigated first with common standard methods like analysis of the plant monitoring data and thermography. Then, these plants were additionally investigated by novel nondestructive methods. With the aid of two innovative characterisation tools, outdoor electroluminescence and UV-fluorescence imaging, hail-induced damaging of solar cells can be detected even when the solar glass of the modules withstood the mechanical impact of the hailstorm and no damages are visible to the naked eye or well recognizable by thermography. The non-destructive, easy to handle and fast characterization technique UV-fluorescence imaging allows the detection and visualisation of hail induced cell damage. Modules showing partial cell breakage and/or micro cracks e as proven by outdoor electroluminescence measurements e and lead to a reduced electrical performance can be unequivocally identified.

Photovoltaic (PV) plants typically suffer from a significant degradation in performance over time due to multiple factors. Operation and maintenance systems aim at increasing the efficiency and profitability of PV plants by analyzing the monitoring data and by applying data-driven methods for assessing the causes of such performance degradation. Two main classes of degradation exist, being it either gradual or a sudden anomaly in the PV system. This has motivated our work to develop and implement statistical methods that can reliably and accurately detect the performance issues in a cost-effective manner. In this paper, we introduce different approaches for both gradual degradation assessment and anomaly detection. Depending on the data available in the PV plant monitoring system, the appropriate method for each degradation class can be selected. The performance of the introduced methods is demonstrated on data from three different PV plants located in Slovenia and Italy monitored for several years. Our work has led us to conclude that the introduced approaches can contribute to the prompt and accurate identification of both gradual degradation and sudden anomalies in PV plants.

The optical loss due to the busbar grid and soldered interconnector ribbons on a three busbar standard multicrystalline silicon solar cell's front side is at 2.3%. One way to reduce this optical loss on cell level and in a photovoltaic (PV) module is to use deep structured ribbons as cell connectors. The standard soldered, flat ribbon is replaced with a glued, multiple structured ribbon. The investigation of shiny soldered flat ribbons and multiple structured ribbons in single-cell mini modules demonstrates the light angle dependency and the benefit for the structured alternative. Additional yield measurements for conventional photovoltaic modules with soldered flat and glued multiple structured ribbons technologies were studied under laboratory conditions as well as in outdoor measurements. The simulations and the experimental findings confirmed that the new structured ribbon design increases the short circuit current and the yield by about 2%.

Two-dimensional (2D) layered semiconductors of Group-III monochalcogenides have gained increasing attention in photonics and electronics. The fabrication of large-scale, inexpensive inks which can be used in printed electronics applications is facilitated by the solution processing of 2D materials. In this study, gallium sulfide (GaS)-, gallium selenide (GaSe)-, and gallium telluride (GaTe)-loaded inks were synthesized and implemented to fabricate phototransistors on SiO 2 \Si substrates. To explore the printed device performances, several color illuminations were applied to the printed phototransistor, and the mobility, photoresponsivity, and external quantum efficiency parameters were compared. Under red-light illumination, the mobility of a GaTe nanoparticle-based phototransistor reached 7.456 cm 2 V −1 s −1 . The responsivity of the GaTe-based phototransistor was found to be the highest, with the value of 9.52 A W −1 under green light illumination. However, GaSe-based phototransistors gave the highest EQE value of 2482 (%) under blue light illumination with the mobility of 7.04 cm 2 V −1 s −1 . This study demonstrates that printable Group-III monochalcogenide inks can be synthesized with desired properties for use in printed electronic applications.