102 research outputs found
A hardware field simulator for photovoltaic materials applications.
No full textThis work is on a photovoltaic field simulator that is a power electronic device which produces direct voltages and currents. These simulate the behaviour of a photovoltaic field working in arbitrary conditions of solar irradiance and temperature. The most important application of the simulator is the testing of inverters. This work also introduces a new model describing the behaviour of photovoltaic modules of any generation. This is particularly useful to scientists and plant designers as it is based only on the electrical parameters that are always reported in a photovoltaic module’s datasheet
Performance prediction of 20kWp grid-connected photovoltaicplant at Trieste (Italy) using artificial neural network
No full textMicrogrids as drivers in the global energy transition towards renewables
No full textContrastare gli effetti negativi dei cambiamenti climatici rappresenta una sfida chiave del 21° secolo. L’uso di combustibili fossili per la produzione di energia, il riscaldamento e i trasporti, è la causa principale delle grandi quantità di gas serra rilasciati nell’atmosfera, responsabili dell’attuale riscaldamento globale. Per limitare le conseguenze dannose dei cambiamenti climatici, il mondo ha urgente bisogno di utilizzare l’energia in modo efficiente, utilizzando fonti di energia pulite. Il contributo descrive l’attuale transizione energetica, in cui l’elettrificazione sta emergendo come una soluzione chiave per ridurre le emissioni, ma solo quando accompagnata da energia pulita, sempre più prodotta a costi minori da fonti rinnovabili. Il contributo illustra i principali trend che stanno guidando il boom delle rinnovabili, con il fotovoltaico che funge da portabandiera. Grid-parity e fuel-parity rappresentano un passo fondamentale nel percorso di crescita (a livello globale a tassi record) di questa tecnologia solare. Il contributo introduce poi le microreti come un sistema in grado di bilanciare la produzione variabile di energia rinnovabile con le attività di generazione tradizionali, contribuendo anche a integrare queste energie rinnovabili nel mix energetico. Esse forniscono energia pulita, efficiente, a basso costo, migliorano la resilienza locale ed il funzionamento e la stabilità della rete elettrica regionale
On the photovoltaic explicit empirical model: Operations along the current-voltage curve
No full textModelling of PhotoVoltaic (PV) devices is today used for a number of activities such as systems monitoring, power forecasting, fault diagnosis, etc. Explicit empirical models based on the datasheet parameters are quite easy to implement in computer-aided calculations and therefore they allow fast evaluations of the electrical behavior, whatever is the test condition (steady-state, transient, etc.). This paper focus on the introduction of a correction factor for one of these models in order to improve its performance for operating points different than maximum power point (MPP). The comparison between the current-voltage (I-V) characteristics predicted by the former and the proposed models clearly shows the effectiveness of the proposed correction factors. The model is tested for different environment conditions and for different materials constituting the PV cells
Grid parity in the Italian commercial and industrial electricity market2013 International Conference on Clean Electrical Power (ICCEP)
No full textThe Italian photovoltaic market is since 2011 the world's largest and represents a success story having attained grid parity for the commercial and industrial (C&I) market of electricity. In this paper, the Levelized Cost Of Energy (LCOE) is calculated for three representative locations in Northern, Central, and Southern Italy, and compared with the C&I end-user electricity price. The grid parity is shown under certain conditions showing that the photovoltaic market is already ready to survive without the feed-in tariff mechanism
Non-destructive vibration-based monitoring analysis of PV modules with encapsulant degradation by frequency change
No full textIn engineering applications, the frequency analysis represents a first and practical step to collect relevant parameters for structural and mechanical diagnostics. Any possible material / component degradation and deterioration can be prematurely detected by frequency modifications that exceed a certain alert value. In this paper, the attention is given to the dynamic mechanical analysis of commercial photovoltaic (PV) modules, in which the solar cells are typically encapsulated in thin viscoelastic interlayers made of Ethylene-Vinyl Acetate (EVA), which are primarily responsible for the load-bearing capacity of the sandwich PV system. As a major effect of ageing, ambient conditions, non-uniform / cyclic thermal gradients, humidity and even extreme mechanical / thermal loads, the rigidity of these films can largely modify and decrease, thus possibly affecting the mechanical capacity of the PV module, and even exposing the solar cells to fault. Knowledge of the effective bonding level is an important step for diagnostic purposes. In this regard, the present study is based on a preliminary non-destructive experimental analysis, and on an extensive parametric Finite Element (FE) numerical investigation of full-scale commercial PV modules of typical use in buildings. The attention is given – for PV module arrangements of technical interest – to the effect of EVA stiffness in terms of vibration modes and frequency sensitivity. As shown, especially compared to newly installed PV modules, any kind of stiffness decrease is associated to major frequency modifications for the composite system, and in the worst configuration, such a frequency scatter can decrease down to −40% the original condition. Such a marked stiffness decrease would be implicitly associated to a weak mechanical performance of the sandwich section, with major stress peaks and deflections in the PV system, even under ordinary loads. The presented results, in this sense, suggest that major consequences can be prevented and minimized by monitoring the vibration frequency of PV modules
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