Novel Mechanically Robust and Environmentally Stable Light‐Weight Colored Photovoltaic Modules Based on Composite Polymer Backsheets

Degradation prediction of encapsulant-glass adhesion in the photovoltaic module under outdoor and accelerated exposures

Photovoltaic (PV) systems are increasingly used to generate electrical energy from solar irradiance incident on PV modules. Each PV module is formed by placing a large amount of PV cells, typically 60, in series. The PV system is then formed by placing a number, typically 10–12, of PV modules in series in a string and sometimes by placing multiple strings of series-connected PV modules in parallel, depending on the desired output voltage and power range. In practical cases, differences will exist between output powers of the cells in the various PV modules, e.g. due to (part of) the modules being temporarily shaded, pollution on one or more PV cells, or even spread in cell behaviour. Due to the current-source-type behaviour of PV cells and their series connection these differences will lead to a relatively large drop in PV-system output power. This paper addresses this problem by adding DC/DC converters on PV-module level. The concept, named ‘delta conversion’, aims at averaging out differences in output power between groups of PV cells within modules and between modules inside the PV system. As a result, all these groups of PV cells can output their maximum available power, such that a drop in output power of the total system is prevented. This paper compares the delta-conversion concept with other state-of-the-art module-level power-conversion concepts and presents first measurement results obtained with a demonstrator system.

Water diffusion simulation in photovoltaic module based on the characterization of encapsulant material using in-situ gravimetric technique

Progress in research and technological developments of phase change materials integrated photovoltaic thermal systems: The allied problems and their mitigation strategies

Summary1. We studied the seasonal dynamics of suspended particulate matter in a turbid, large shallow lake during an annual period (2005–06). We relate the patterns of seston concentration (total suspended solids), phytoplankton biomass and water transparency to the seasonal pattern of incident solar radiation (I0). We also report the seasonal trends of phytoplankton primary production (PP) and photosynthesis photoinhibition due to photosynthetically active radiation (PAR) and ultraviolet radiation (UVR) (Iβ and UV50).2. We first collected empirical evidence that indicated the conditions of light limitation persisted during the study period. We found that the depth‐averaged irradiance estimated for the time of the day of maximum irradiance (Imean–noon) was always lower than the measured onset of light saturation of photosynthesis (Ik).3. We then contrasted the observations with theoretical expectations based on a light limitation scenario. The observed temporal patterns of seston concentration, both on a volume and area basis, were significantly explained by I0 (R2 = 0.39 and R2 = 0.37 respectively). The vertical diffuse attenuation coefficient (kdPAR) (R2 = 0.55) and the depth‐averaged irradiance (Imean) (R2 = 0.66), significantly increased with the I0; while the irradiance reaching the lake bottom (Iout) significantly decreased with the incident irradiance (R2 = 0.49). However, phytoplankton biovolume maxima were not coincident with the time of the year of maximum irradiance.4. A significant positive relationship was observed between PP estimated on an area basis and I0 (R2 = 0.51, P < 0.001). In addition, the parameters describing the photosynthetic responses to high irradiances displayed marked seasonal trends. The photosynthesis photoinhibition due to PAR as well as to UV were significantly related to incident solar radiation (PAR: R2 = 0.73; UV: R2 = 0.74). These results suggest adaptation of the phytoplankton community in response to changes in incident solar radiation.

Increasing fossil fuel prices, electricity demand, and global concern for greenhouse gas emissions have generated an increase in research of novel renewable energy technologies for green power generation. Renewable solar-photovoltaic (PV) systems are known fosr their ability to directly convert the solar energy into electrical energy for locations where there is a desperate need and demand for electrical power, e.g. Communities and towns in remote locations, and solar energy is available. PV systems tend to generate more power if they are operated efficiently. The inclination (tilt) angle at which a solar photovoltaic (PV) module is sloped from the horizontal plane is one of the most influencing system parameters that affects the electrical power output from the PV system. This is due to the fact that the variation in the tilt angle affects the amount of incident solar radiation received on a PV system and utilized by the load once installed at a certain site. In this work, a mathematical model is used to estimate the total solar radiation incident on an inclined surface and to determine the optimum inclination angle for maximizing power generation from a solar PV system installed in Slave Lake, Alberta, Canada. The total solar energy received on the optimally inclined PV surface is computed for all months in a year. It was found that the monthly average optimum tilt angle of the PV system varied from a minimum value of 9o in the month of June to a maximum value of 78o in the months of January and December. The yearly average monthly optimum tilt angle for the fixed PV system in Slave Lake was estimated to be at 47o. It was also found that the highest maximum incident radiation of approximately 21.30 Mj/m2 for the whole year occurred in the month of June, where as approximately 30.4% of this value (the lowest in the year) occurred in the month of December. The minimum incident solar radiation for all months in the winter season occurred at almost zero tilt angle and that the variation of the monthly average daily sunlight hours varied from 6.9 hours in December to as high as 17.1 hours in June.

We present an evaluation of the silicon solar cell as well as the photovoltaic (PV) module size and its effect on thermomechanical stress. The evaluation is based on finite-element method (FEM) simulations. Within these simulations, we perform parameter variations of the number of solar cells within a PV module from 60–140 cells, of the cell size from 156.0–161.75 mm, and the cell format from full cells down to quarter cells. The FEM simulations cover the lamination process, mechanical load, and thermal cycling for glass–foil as well as glass–glass modules. The presented results reveal correlations between the solar cell and module size with the stress in the solar cells. We also find that the interaction of the laminate with the module frame plays a significant role in thermal cycling. Of the varitations under investigation, the increase in cell size has the largest effect on the stress. However, at a mechanical load of 2400 Pa, glass–foil modules with less than 96 solar cells have a negligible failure probability. The advantage of placing the solar cells in the neutral axis of the laminate is proven by the negligible tensile stress values for all variations of the glass–glass modules.

An accurate model for photovoltaic (PV) modules to determine electrical characteristics and thermodynamic performance parameters

The current industrial standard photovoltaic (PV) modules are dominated by crystalline‐silicon (c‐Si) PV technology, which cannot be easily recycled. This has generated worldwide concerns regarding the scarcity of critical raw materials and large waste streams of PV modules in the coming years. To overcome this problem, a lot of ongoing research focuses on upscaling the recycling process of present c‐Si module designs by chemical, thermal and mechanical processes. Alternative research focuses on the development of new PV modules with enhanced circularity by design. In this work, we propose a new circular PV module design based on liquid‐encapsulation technology in which silicon solar cells are encapsulated with a suitable liquid and an edge sealant instead of a polymer sheet. Our optical studies show that the selected liquids exhibit similar optical performance to ethylene vinyl acetate (EVA) due to their comparable refractive indices. We fabricate one‐cell prototypes and observe comparable efficiency of liquid‐encapsulated and EVA‐encapsulated modules, signifying recyclable module design without an additional efficiency loss. To validate the module performance, we also simulate the optical performance of modules with different encapsulation materials. Furthermore, the new modules retained more than 95% of their efficiency after inducing accelerated ageing through damp heat, thermal cycling and humidity freeze tests, indicating the liquids as an excellent encapsulant material for PV. In the end, we disassemble the liquid‐filled PV module and show the recovered components, which can directly be reused in new products. Therefore, this modular design bypasses the recycling process. Even more promising, the liquid encapsulation can improve the stability of perovskite/c‐Si tandem solar cells due to the moisture barrier, which will be studied in the future. Adding further possibilities, in principle, with additional engineering, the liquid encapsulation could be used in a heat loop to turn the PV module into a photovoltaic‐thermal (PV‐T) module, thereby boosting the efficiency potential beyond that of traditional PV concept.

Статья представляет собой обзор, в котором рассматривается проблема нехватки научной основы для прогнозирования долговечности полимерных композиционных материалов (ПКМ) при длительной эксплуатации. Особое внимание уделяется влиянию ультрафиолетового (УФ) излучения и механических нагрузок на деструкцию ПКМ. Текст содержит результаты исследований, связанных с деградацией полимеров под воздействием УФ-излучения, влиянием УФ-облучения на механические свойства полимерных композитов с углеродным волокном, а также механизмами пожелтения тонких пленок эпоксидных и винилэфирных смол. The article is a review that addresses the problem of insufficient scientific basis for predicting the durability of polymer composite materials (PCM) during long-term use. Special attention is given to the influence of ultraviolet (UV) radiation and mechanical loads on PCM degradation. The text presents research findings related to polymer degradation under UV radiation, the impact of UV exposure on the mechanical properties of carbon fiber-reinforced polymer composites, as well as the mechanisms of yellowing in thin films of epoxy and vinyl ester resins.

In this work, we present three methods to extract model physical parameters of a photovoltaic solar module modelled by a single-diode electronic circuit. The model physical parameters we are looking for are photocurrent Iph , saturation current Is , ideality factor η, series resistance Rs and shunt conductance Gp . The first method is based on exact solution of module characteristic equation, the second one uses exact expression of dynamic conductance and the third one makes use of exact expression of the integral of translated current-voltage characteristics (I-Isc ). In all these extraction methods, we achieve numerical fitting of experimental data of output current, differential conductance and area under translated characteristics with suitable analytical expressions to get model physical parameters at standard test conditions (STC). Then, we assume these values as initial conditions and derive exact analytical expressions reporting effects of module temperature and incident solar irradiance on photocurrent, saturation current and ideality factor using temperature coefficients provided as well as irradiance coefficients extracted from module manufacturer datasheet. We examine new analytical expressions of model physical parameters in the case of Shell SQ80 photovoltaic solar module at arbitrary operating conditions of module temperature and solar irradiance. We evidence good agreement between experimental characteristics and forecasted analytical characteristics generated by new analytical expressions.

Current mismatch in PV panels resulting from different locations of cells in the panel

An accurate thermal model for the PV electric generation prediction: long-term validation in different climatic conditions

Ultra-low energy reverse osmosis with thermal energy recovery from photovoltaic panel cooling and TFC RO membrane modification

A large part of incident solar radiation on photovoltaic (PV) modules is converted into heat, leading to overheating and reduction of PV modules performance. The present work investigates the impact of rectangular aluminium fins (RAFs) and evaporative cooling represented by cotton wicks immersed water (CWWs) on the performance and thermal behaviour of the PV module. Results indicate that the evaporative cooling attained better cooling potential than RAFs, in which the PV module temperature was reduced by 22.3%, and the output power was enhanced by 73% thanks to continuous cooling of the PV module. A slight improvement in the PV module performance was observed with RAFs due to the increased heat transfer area, which reduced temperature by up to 6.7% and increased the output power of the PV module by up to 21.3 %. Exergy analysis shows a gradual increment of the electrical exergy and exergy efficiency using CWWs, which reduces the entropy generation of it more than RAFs. The study concluded that PV modules without cooling in hot climate areas may deteriorate their performance significantly.