PV Module Manufacturers Research Articles

RECYCLING OF PHOTOVOLTAIC CELLS – A REVIEW

The growth of solar energy has been remarkable between 2013 and 2022, with a doubling of capacity from 80 GW to 197 GW. To recover valuable materials and mitigate environmental impact, it is imperative to have effective waste management practices in place. While recycling technologies are still in the experimental phase, the EU has put in place legal frameworks for manufacturer liability. There are continuous efforts being made to develop commercially viable technologies for the management of end-of-life PV module waste. An important part of the system of renewable sources is the establishment of a high-quality and efficient waste management system, which is contained within the concept of the circular economy. PV modules will at some point reach the end of their life cycle, which is estimated to be around 25 years, and become waste, therefore a lot of effort is currently being put into research and development of different waste treatment technologies of PV modules. They are still in the experimental phase, and few technologies become commercially available. Also, the management of waste generated at the end of the life cycle of photovoltaic technology is not yet fully regulated. However, at the level of the European Union, there is a legal framework for the liability of PV module manufacturers according to Directive on electric waste and electronic equipment. This paper is a detailed review of recycling technologies based on existing literature.

Energy performance of commercial c-Si PV modules in accordance with IEC 61853-1, -2 and impact on the annual specific yield

As energy yields of photovoltaic modules are highly related to local climate and ambient conditions, it is necessary to assess the energy-yield performance of PV modules under various operating conditions. This work compares commercial crystalline silicon (c-Si) based PV modules (including mono c-Si Al BSF, mono c-Si PERC, multi-crystalline (mc-Si) Al BSF, and n-type c-Si solar cells) sampled from 27 PV module manufacturers located in the Asia-Pacific region between 2016 and 2022. Several test items were compared including: (i) light-induced degradation (LID), (ii) irradiance-temperature-efficiency (GTE) matrix, (iii) angular response and (iv) temperature coefficients, which are correspondingly performed according to IEC 61215-1, -1-1, -2 and IEC 61853-1, -2. The coefficient of variation (CoV) was calculated to express the module-to-module differences within similar technology types. Benefiting from the technological innovation of c-Si based PV modules, emerging PV modules feature better performance in some extreme ambient conditions, such as low irradiance, high ambient temperature, and high ratio of diffuse irradiance. The analysis of CoV indicates that the difference of irradiance-dependent and thermal behavior between modules within the same technology may exceed the differences between different technologies. Using synthetic hourly meteorological data of 5 sites from MeteoNorm in PVsyst, the annual specific yield of four technology groups of PV modules were simulated and compared. Overall, it is shown that the maximum differences as large as 7.34% in terms of PV module's specific yield are expected within same PV technology, which exceeds the maximum difference of 2.16% obtained for specific yields of different PV technologies.

Creep-fatigue lifetime estimation of efficient photovoltaic module ribbon interconnections

As the solar PV harvesting energy system are becoming more important sector of renewable energy day to day, improving the efficiency of the solar PV module and reducing the cost of modules are receiving more attentions of PV module manufacturers. Design of the PV module interconnection ribbons is one of the main focus for developing the efficiency of the PV modules and improving the reliability of the modules. In the last decade, new designs for the PV module interconnection ribbon have been introduced, however, there is still a need to optimize their configuration and geometry to achieve higher reliability without dropping the efficiency of the PV modules. Indeed, solely using the wider interconnection ribbons (to provide more joint length) may increase the reliability of the module, but it directly reduces the efficiency of module due to more shading effect. This study provides the results for determining the optimal design for long-term reliability of PV module interconnections. Three main PV module ribbon interconnection designs including Conventional Ribbon (CR), Light-Capturing Ribbon (LCR), and Multi-Busbar (MBB) interconnections are compared in terms of number of cycles to creep-fatigue failure. This study uses the FEM simulation and creep-fatigue reliability formulations to find the effect of the main geometrical parameters on the failure of different PV module ribbon interconnection designs. The finding showed that the MBB interconnections has up to 15 % higher creep-fatigue lifetime compared to the LCR and the CR interconnections.

Damp heat resilient thermoplastic polyolefin encapsulant for photovoltaic module encapsulation

Thermoplastic polyolefin (TPO) is a non-crosslinking material used in photovoltaic module encapsulation. TPO thermal degradation and its weather stabilities are still not known. In this work, TPO laminates were prepared and subjected to extended damp-heat weather test. TPO encapsulant properties were studied and compared with the most commonly used encapsulant, Ethylene-Vinyl Acetate (EVA). Four times lower rate of transmittance loss and increment rate in the yellowness index values have been found for TPO compared to EVA laminate. Damp-heat induced degradation mechanism, and its components were studied using Raman and Fourier-transform-infrared (FTIR) spectroscopy. Raman spectra revealed that the carbonyl group loss rate at the edge is one order of magnitude higher than the center. FTIR has shown a higher rate of acetic acid and hydroxyl group formation in EVA as compared to the TPO. FTIR also demonstrated that TPO has a lower water absorption because of its nonpolar nature, whereas EVA shows more water absorption due to its polar nature. The rate of change in thermal properties of TPO and EVA encapsulants were studied through the heat-cool-heat cycle. A higher rate of increment in the degree of crystallinity is found for EVA as compared to the TPO encapsulant during the extended damp-heat acceleration test. This study helps to understand the TPO and EVA encapsulants degradation behavior, degradation components, and mechanism to the encapsulant researchers and PV module manufacturers when a PV module experiences the hot-humid conditions. This TPO may result in the industry adopting the different PV modules for fabricating.

Performance loss rates of floating photovoltaic installations in the tropics

Floating photovoltaics (FPV) is a relatively new concept for the PV community. The operating environment of FPV systems is different from that of conventional PV systems and offers the potential advantage of higher energy yield. Consequently, there is a rapid increase recently in both the installed and planned capacity of FPV systems worldwide. However, there exists a lack of knowledge and data about the performance stability of FPV systems. This paper presents, for the first time, a detailed analysis of the performance stability of FPV systems from one of the largest FPV testbeds worldwide, located on the Tengeh Reservoir in Singapore (tropical rainforest climate). The study is based on data gathered during the operation period of April 2017 to March 2020. Three commonly-used statistical methods are deployed to calculate performance loss rates (PLRs) — ordinary least squares (OLS), seasonal and trend decomposition using locally weighted scatterplot smoothing (STL) and year-on-year (YoY) methods. The mean PLRs of eight monitored FPV strings (all deploying crystalline silicon modules) based on OLS, STL and YoY are −0.7, −0.5 and −0.5%/year, respectively; the median annual PLRs (in the same order) are −0.6, −0.5 and −0.5%/year, respectively. These values are in line with the performance warranty from PV module manufacturers. Furthermore, a comparison is also made to two monitored PV strings (both deploying crystalline silicon modules) from a nearby rooftop reference system. Overall, there is no significant difference in the performance stability between the rooftop and the FPV installations in the testbed during the first three years of operation.

Новый метод определения параметров однодиодной модели фотоэлемента на основе табличных данных

Very few manufacturers that are providing a wide range of graphical data necessary to use high-performance predictive tools for PV systems. On the other hand, reliable graphical data require precise laboratory measurements that increase manufacturing costs. Furthermore, most of the methods used to determine photovoltaic performance require iterative techniques, additional mandatory information and users with a certain level of knowledge. For this reason, PV system designers have to choose between the use of cheap PV modules, lacking in technical data, and the reliable energy predictions that are possible only if the current–voltage characteristics are provided by the PV module manufacturers. This paper presents a novel method to extract the single diode five parameters model for different manufacturer's modules using the minimum set of technical data that are usually provided by all manufacturers. The proposed procedure uses an accurate and easy method that does not require iterative techniques, other obligatory information or users with special knowledge but only datasheet values from a technical catalog of photovoltaic modules to simulate photovoltaic performance. The method uses an empirical relationship that enables to calculate the initial values of series and shunt resistances and extracts the parameters of the model from datasheet values provided by manufacturers only. The capability of the proposed model to calculate the current–voltage characteristics was tested by comparing the results with data measured by different manufacturers’ panel models (mono-crystalline and poly-crystalline) silicon modules. The method was also compared with other similar methods. The results of the new model application confirm the reliability of the procedure.

Nondestructive Determination of Climate‐Specific Degradation Patterns for Photovoltaic‐Module Encapsulation

AbstractDuring the service life of a PV module, various different degradation mechanisms can be induced. Polymer degradation depends strongly on the external conditions, which are determined by the climate and the specific conditions of the module. Nondestructive measurements of the degradation behavior of the PV‐module encapsulation material ethylene vinyl acetate (EVA) were performed. We present results of Raman spectroscopic measurements on full‐sized PV modules from several different PV module manufacturers, which were exposed outdoors in different climates for up to three years. This way, the different degradation mechanisms that are induced under the influence of different climatic conditions during outdoor exposure could be investigated. It was found that the degradation pattern, detected by Raman spectroscopy, was rather similar for the investigated climates, but the extent of polymer degradation was found to be higher for tropic and arid climates than for moderate or mountain climates.

Performance analysis of field exposed single crystalline silicon modules

This paper presents results on the field performance degradation of mono-crystalline silicon PV modules from 11 PV module manufacturers under identical field conditions. The modules were installed in both fixed tilt and manual tracking modes. The data were monitored using a CR23X Data logger and I– V curves were taken using SPI 240A Sun simulator. The performance parameters analyzed are V oc, I sc, P max, I mp, V mp and the fill factor, as a function of time of field exposure. Qualitative studies are made on physically visible defects such as EVA coloration, cell de-laminations, corrosion of solar cell grid, corrosion of end strip connected in the terminal box, failure of by-pass diode, detachment of the terminal box, tearing of tedlar sheet, etc. The effect of field exposure on the performance parameters indicates that the qualification standard (s) needs to be reviewed and revised if the modules are to perform for ∼20 years under actual field conditions in India.

A method for estimating the long-term performance of direct-coupled PV pumping systems

A method is developed to predict the long-term performance of direct-coupled PV pumping systems. The method uses only information available from the PV module and pump-motor manufacturers. Weather data are “generated” from monthly averages of horizontal radiation and ambient temperatures using well-known weather data statistics. The method predicts monthly pumped water to within 6% of TRNSYS predictions based on hourly weather data. The use of a single monthly-average day is shown to underpredict monthly pumped water at low monthly average radiation levels and overpredict monthly pumped water at intermediate radiation levels. Only at high radiation levels does the use of a single monthly-average day provide a reasonable estimation of monthly pumped water.