Bifacial Photovoltaic Modules Research Articles

Albedo Reflection Modeling in Bifacial Photovoltaic Modules

This paper focuses on the analytical modeling of albedo reflection in bifacial photovoltaic modules, with particular emphasis on the backside. First, we critically examine the approaches proposed in the literature, presenting them with a tutorial style and a uniform nomenclature. These approaches are demonstrated to yield physically meaningless results, as they erroneously assume that the ground area shaded by the module acts as a source of reflected irradiance independent of the portion of sky dome visible to such an area. Then we introduce a correction based on the view factor between the shaded area and the sky. The result is a comprehensive and accurate analytical model that also describes the case of suspended panels and can be easily implemented into PV plant simulators.

Experimental Study of Bifacial Photovoltaic Module Performance on a Sunny Day with Varying Backgrounds Using Exergy and Energy Analysis

In this research, ethe performance of bifacial photovoltaic (PV) modules under varying background conditions is explored, specifically green grass, brown clay, and white gravel, on a sunny day. By leveraging both exergy and energy analysis, this research aims to provide a comprehensive evaluation of bifacial module efficiency compared to traditional monofacial modules. The experimental setup simulates diverse installation environments, including rooftops and ground-mounted systems, by varying background reflectance. Key performance metrics such as energy yield, exergy yield, and overall efficiency were measured. The findings reveal that bifacial modules installed over white gravel backgrounds achieve the highest exergy profile and efficiency during peak solar radiation periods, attributed to the enhanced reflectivity of white gravel. These insights can inform strategic decisions regarding the selection and placement of bifacial modules to optimize energy and exergy outputs in real-world scenarios. This study contributes valuable knowledge to the advancement of renewable energy technologies, offering guidance for researchers, developers, and policymakers focused on sustainable energy solutions.

Improved Performance of Bifacial Photovoltaic Modules with Low-Temperature Processed Textured Rear Reflector

Improved Performance of Bifacial Photovoltaic Modules with Low-Temperature Processed Textured Rear Reflector

PVSails: Harnessing Innovation With Vertical Bifacial PV Modules in Floating Photovoltaic Systems

AbstractIn the context of offshore floating photovoltaic systems (FPVs), this paper explores the use of bifacial photovoltaic modules installed in the vertical position. The energy harvested from the rear face of vertically configured bifacial PV modules compensates for the reduced production at the front face of the module, and this demonstrates the potential of bifacial technology for offshore applications. By comparison, most existing horizontally tilted bifacial FPV systems gain only a small benefit in production from the rear face of the module due to the minimum radiation received, and what also must be taken into consideration is the negative effect of significant soiling owing to the low tilt angle of the PV modules. Hence, to overcome these drawbacks, we have developed the innovative “PVSail” concept, which explores the deployment of vertical FPV systems on floats, buoys, or poles/minipiles. Floating vertical bifacial PV systems (VBPVs) have huge potential to harness all the energy generation capabilities enhance by reflected light, especially from snow‐covered surfaces in northern regions. Our analysis considers a patented mooring and vertical PV system that allows the VBPV structure to align with the prevailing wind direction to shed wind loads, and our numerical analysis explores the potential of VBPV applied to Catania in Italy and Nigg Bay in the United Kingdom. Our analysis study has revealed that across an azimuth angle range (0°–180°), vertical bifacial modules experience roughly a 9% decrease in energy yield at Catania and about a 5% energy yield gain in higher latitude regions like Nigg Bay. Additionally, increasing the latitude of the installation location of VBPV reduces the energy yield sensitivity to the orientation, that is, azimuth angle. The PVSail concept opens the door to novel deployment possibilities in offshore renewable energy projects.

A systematic literature review of the bifacial photovoltaic module and its applications

AbstractBifacial modules can absorb radiation on both sides, increasing energy yield per unit area. Climatic conditions, mounting configuration, and system parameters influence the energy yield. The flexibility of bifacial modules allows for various installation orientations, including vertical and east‐west, which can help balance load profiles and reduce bottlenecks. Bifacial solar cells are found to provide higher current density and power compared to monofacial cells. Under optimum conditions, bifacial modules offer up to 30% more energy than conventional modules. Comparative assessments also demonstrate higher energy output from bifacial modules, especially on cloudy days, with low light intensity. Increasing ground reflectance (albedo) to 0.5 can further enhance the bifacial gain worldwide. The progress in performance modelling and accurate energy yield prediction has led to widespread adoption in residential and commercial applications and integration into emerging systems like floating PV and agro‐photovoltaic systems. Bifacial photovoltaic (PV) technology has received much interest, with the International Technology Roadmap for Photovoltaic (ITRPV) projecting a market share of 85% for bifacial PV cells by 2032. This study highlights the research on bifacial PV technology during the last 13 years and also discusses future trends and challenges. Furthermore, recommendations are made to ensure the bankability and scalability of bifacial PV modules.

Environmental impact assessment of the manufacture and use of N- type and P-type photovoltaic modules in China

For a long time, solar power has been considered a clean and non-polluting energy source because it absorbs sunlight without consuming other energy or materials and does not emit pollutants. Nevertheless, the manufacturing and end-of-life stages of solar power systems leave an environmental footprint and produce pollutants. Hence, a global perspective on photovoltaic (PV) systems using life cycle assessment methodology is necessary. Here, we investigated the life cycle impacts of P- and N-type PV modules in terms of their energy consumption, carbon emissions, and human toxicity potential. In addition, the energy payback durations of P- and N-type PV modules were computed. In this study, we used the Life Cycle Assessment Basic Database from the National Engineering Laboratory of Industrial Big Data Application Technology at Beijing University of Technology to create a life cycle assessment model for N-type PV modules. Subsequently, we performed a life cycle assessment of Chinese silicon N-type- and P-type PV modules. The research system encompassed the production processes for metallic silicon materials, solar-grade silicon materials, silicon wafers, cells and modules, utilization, recycling, and other interrelated processes. We found that the production and processing of silicon-to-solar-grade polysilicon feedstock were crucial stages that significantly affected the energy consumption and environment of P- and N-type PV modules in China. The high electricity consumption of this process, combined with the dominance of coal power in China's electricity structure, contributed to the substantial energy consumption and environmental impacts of the PV modules. Therefore, this stage is critical for the low-carbon and environmentally sustainable manufacturing of N-type PV modules in China. Carbon emissions for both the P-type and N-type PV modules were lower only during the cell production phase but higher during the other stages when compared to the P-type and N-type PV modules. The n-type bifacial PV modules yielded the highest return on investment in terms of energy. Different regions and installation types have a substantial impact on the carbon emissions of P-type and N-type PV modules. Projections indicate that the potential to lower carbon emissions from n-type PV modules will increase by 2060.

Study of bifacial photovoltaics with fluorinated ethylene propylene as an anti-reflective layer

Bifacial photovoltaics is a type of solar photovoltaics technology that is fast growing in popularity owing to the several advantages it offers. In this study, the inclusion of fluorinated ethylene propylene polymer as one of the constituent materials in bifacial photovoltaic modules under various configurations and its effect on the module’s optical performance was investigated and compared with a commercial bifacial module. Monte Carlo ray tracing was used to conduct the study and the system was analyzed under both non tracking and uniaxial tracking conditions for varying surface albedo values corresponding to an ideal scattering surface, white concrete and sand. The analyses performed under normal incidence condition revelated that the net irradiance on the PV layers varied by as much as 96.0314 W m−2 between the best and worst performing bifacial configurations. Under uniaxial tracking, the top and rear surfaces of the PV modules could cumulatively be subjected to 21.799 kWh of solar irradiation flux per day over a generation window of eleven hours. The proposed changes could offer cost savings of USD 0.0118 per panel per day and up to an additional 5.802 kg of CO2 equivalent offsets per panel per year.

Design optimization of large-scale bifacial photovoltaic module frame using deep learning surrogate model

Recently, the wafers used in solar cells have been increasing in size, leading to larger module sizes and weights. The increased weight can cause deflection of photovoltaic (PV) module, which may lead to decreased cell efficiency. In this study, we developed a deep neural network (DNN)-based finite element (FE) surrogate model to obtain the optimal frame design factors that can improve deflection in large-scale bifacial PV module. Initially, an FE model was constructed for large-scale bifacial PV module. Based on this, the FE surrogate model was trained using 243 FEA datasets generated within the proposed range of factors. Furthermore, it was improved through Bayesian optimization and k-fold validation. As a result, the final loss value was 3.743×10-4\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$3.743 \ imes 10^{-4}$$\\end{document}, and the average mean absolute percentage error (MAPE) and coefficient of determination (R2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$R^2$$\\end{document}) values for deflection and weight were 0.0017, 0.9972 for the training set, and 0.0020, 0.9962 for the test set, respectively. This indicates that the trained FE surrogate model possesses significant accuracy. After generating 1 million datasets within the range of frame design factors, the trained model was used to obtain predictions. Based on this data, the frame design factors that minimize both deflection and weight were identified as about a = 1.5, b = 13.7, c = 1.5, d = 3.0, e = 4.3. At this point, the deflection was 11.1 mm, and the weight was 3.6 kg. After altering the frame shape with the derived factors, FEA was conducted. The results matched for both deflection and weight, with almost no error. At this point, the weight increased by approximately 12.8% compared to the existing, while the deflection decreased by about 9.6%. Additionally, we analyzed the relationship between deflection and weight for each factor and secured the basis for the derived results. Consequently, our FE surrogate model accurately predicted the FEA results and quickly identified the optimal factors that minimize deflection and weight.

A concentration reflector device of a bifacial photovoltaic module

Abstract At present, the development of bifacial photovoltaic modules is rapid, but there is a lack of concentrating light devices in bifacial photovoltaic modules for power generation. This paper analyzes the changing patterns of solar altitude and azimuth angles and the influence of plane mirror reflection concentrating light on the performance of bifacial photovoltaic power generation. Using MATLAB programming, it calculates the pattern of change of the intensity of reflected light with the installation height h of the plane mirror. Then, a double plane mirror concentrating device is designed, which can do real-time dynamic tracking of the sun’s azimuth and altitude angle and realize the power generation capacity of the PV module is multiplied.

Stochastic approach for maximum power point determination for bifacial PV modules by implementing two different cell models

PurposeThis paper presents the determination of the maximum power point of a bifacial photovoltaic (PV) system using two different cell models. The optimal power point is determined by using genetic algorithm (GA), as an optimisation tool. The purpose of this paper is to find which of the two analysed models gives better results in the determination of the maximum power point of a bifacial PV system for different solar irradiations. The quality of the results gained from both models is analysed based on the value of the objective function.Design/methodology/approachIn this research work, the maximum power point of bifacial PV modules is determined by using two different PV cell models, such as the simplified and two-diode models of PV cells. Based on the input electrical data for the analysed bifacial PV module as well as the mathematical model of the two PV cell presentations, the values for the current and the voltage at the maximum power point for a given solar irradiation and working temperature are determined by the algorithm for each solution in the population and generation.FindingsFrom the presented results and the performed analysis, it can be concluded that GA is quite appropriate for this purpose and gives adequate results for both models and for all working conditions. The two-diode model was found to be more suitable compared with the simplified model due to its complexity. Therefore, although the power difference for each of the scenarios for the two compared models does not differ significantly among the two models, it is in favour of the two-diode model. Which implicates that the for fast and simple calculation the simplified model can also do the job.Practical implicationsThis approach can be very successfully applied in the design process of a PV plant to forecast the output characteristics of the PV system if there is enough information about the weather conditions for a given location. This procedure can be very helpful in the process of selection of right PV module and inverter for a given location.Originality/valueAn optimisation technique using GA as an optimisation tool has been developed and successfully applied in the determination of the maximum power point for a bifacial PV module using to different models of solar cell. The results are compared with the analytically determined values as well as with the values given from the producer and they show good agreement.

3D View Factor Power Output Modelling of Bifacial Fixed, Single, and Dual-Axis Agrivoltaic Systems

This study investigates the performance of agrivoltaic systems employing bifacial photovoltaic modules. A comparison between yield in Sweden and Italy was carried out. Three agrivoltaic system designs were evaluated: vertical fixed, single-axis tracker, and dual-axis tracker. The results showed that the specific production varied between 1090 to 1440 kWh/kWp/yr in Sweden and 1584 to 2112 kWh/kWp/yr in Italy, where the lowest production was obtained with the vertical fixed agrivoltaic system while the highest production was obtained with the dual-axis tracking agrivoltaic system. The vertical fixed design had a higher electricity production during low solar elevation angles, while the single-axis and dual-axis tracking designs had significantly higher power production during mid-day. The electricity production gain using a dual-axis tracker design was mostly during mid-day, but the increase compared to the single-axis tracker was only 1-2%. The study concludes that low-height, fixed agrivoltaic systems without tracking are well-suited for high-latitude countries like Sweden, while elevated systems with tracker solutions are more suitable for locations like Italy. The findings suggest that the performance of agrivoltaic systems with bifacial photovoltaic modules is highly dependent on geographical location and the specific characteristics of the crops grown beneath them.

A comparative study of bifacial versus monofacial PV systems at the UK’s largest solar plant

Abstract This paper presents an extensive analysis of the UK’s largest bifacial photovoltaic (PV) power plant, located in North Yorkshire. Commissioned in January 2020, this trailblazing facility, with a total installed capacity of 34.7 MW, is a benchmark for the evaluation of bifacial solar technology within the region. This pioneering study provides a thorough comparative assessment of bifacial and monofacial PV systems through a methodical investigation of their energy production, degradation rates, and spectral responses over a 4-year operational period. Our findings reveal that bifacial PV modules, distributed across four segments of the power plant, demonstrate a remarkable average power gain ranging between 15.12% and 17.31% compared with monofacial modules. Despite experiencing marginally higher annual degradation rates—1.17% for bifacial compared with 0.91% for monofacial systems—bifacial modules show superior resilience and energy yield, particularly during winter months when albedo effects are pronounced due to snow coverage. The study also highlights the strategic importance of spectral response analysis in optimizing PV performance. Bifacial modules have shown greater efficiency in capturing infrared radiation—a property that could be exploited to enhance overall energy yield under specific environmental conditions. The empirical data indicate a consistent performance of bifacial modules with an average normalized energy output clustering around the expected efficiency level. Therefore, the results of this study are pivotal for understanding the practical implications of deploying bifacial PV technology on a large scale. They provide valuable data for stakeholders in the solar energy sector, guiding future installations and innovations in solar panel technology.

Modelling of bifacial photovoltaic farms to evaluate the profitability of East/West vertical configuration

East/West (E/W) vertical bifacial photovoltaic (PV) modules can achieve higher profits than the conventional North/South (N/S) tilted configuration depending on the design choices and external conditions. In this study a model based on 2D view factor concept is developed to estimate the power generated by a large-scale bifacial PV farm, considering the non-uniformity of the incident irradiance and the spectral impact. A validation using measured data is performed, focusing on the non-uniformity of the rear irradiance. This model is used to compare the profitability between E/W vertical and N/S tilted PV farm configurations, considering higher prices during noon with respect to morning/evening periods. The results identify the ratio between these two price values as the key variable that influences the comparison between the PV farm configurations. Specifically, a sufficiently high price ratio ensures the higher profitability of E/W vertical modules, however, the exact value is dependent on the location and the design variables. In general, higher row-to-row distance and lower diffuse fraction enhance the profitability of the E/W vertical over the N/S tilted configuration. On the other hand, elevation of the modules, curtailment strategies and hybrid solutions have a minor influence.

Spectro-angular analysis of roadside-integrated bifacial solar power systems with reflecting sound barriers

Bifacial photovoltaic modules along highways provide energy supply and act as sound barriers simultaneously. This study examines the impact on energy production when incorporating sound barriers with varying light reflection properties into this integrated solar infrastructure along roadways. Specifically, we use advanced computational simulations to analyze the effects of integrating black, ideal specular, and ideal diffuse (Lambertian) reflectors into an existing highway solar power plant located in the Netherlands. Our analysis combines realistic spectro-angular irradiance data as input with our in-house reverse ray tracing software. Our calculations show that for an east-west facing system, an ideal diffuse reflector increases the annual yield by 70%, while a specular reflector decreases the yield due to shading. Most notably, the diffuse reflector doubles the energy yield during winter months, thereby offering a pathway to decrease the seasonal energy demand and supply gap.

Quantifying spectral albedo effects on bifacial photovoltaic module measurements and system model predictions

AbstractWe provide a comprehensive analysis of the effect of spectral albedo on photovoltaic (PV) module measurements and system model predictions. We demonstrate how to account for albedo in indoor bifacial device measurements by adjusting the applied irradiance using the scaled rear irradiance method, exemplified on fabricated silicon heterojunction (SHJ) modules. System model performance is studied using a detailed 3D finite‐element model, DUET, for fixed‐tilt and horizontal single‐axis tracked (SAT) arrays between 15 and 75°N. Spectral effects cause variations in measured SHJ module short‐circuit current up to 2% and efficiency variation up to 0.3% abs. We further demonstrate that rear‐side spectral mismatch factors (SMMs) resulting from including or omitting spectral albedo in PV system modeling vary between ±13%, while total (front+rear) SMMs vary up to 3%, depending on the deployment configuration and latitude. SAT array SMMs are weakly correlated with latitude, while fixed‐tilt array SMMs increase with latitude, driven by an increasing proportion of ground‐reflected light on the front‐side of modules. Ground‐reflections can constitute between 2% and 32% of total incident module irradiance, with notably high (>10%) contributions for fixed‐tilt arrays at high latitude. Effects of spectral albedo are most significant for: (1) fixed‐tilt deployments at high latitudes, (2) wide bandgap technologies such as perovskite and cadmium telluride cells, (3) albedos which vary steeply over the technology's absorption range, and (4) high albedo ground covers. Overall, we demonstrate that omitting spectral albedo effects can result in PV measurement and system‐level modeling uncertainties on the order of several percent in these cases.

Simulink model of a bifacial PV module based on the manufacturer datasheet

The paper proposes an update of a mathematical model of a Photo-Voltaic (PV) module, considering the possibility that also the rear face of the PV module produces energy. The proposed approach allows to write a new descriptive equation, whose terms are function of the information always available in the modern datasheet of the PV module’s manufacturers. This implies that no pre-processing of the datasheet’s parameters is needed to use the proposed model, whichever are the solar irradiance and the cell/module temperature. The model considers the total solar radiation (front and back side), such that the produced energy increases. Simulink environment is used to calculate the total solar radiation.

Performance of stand-alone bifacial photovoltaic module using non-biodegradable waste as reflectors for tropical climatic region of southern India: An experimental approach

Bifacial photovoltaic modules (Bi-FM) generate more power compared to mono-facial modules (Mo-FM) even in diffused light conditions. Deployment of reflectors in Bi-FM increases the cost of implementation. The unique feature of this proposed work is that it utilizes waste material as reflectors. The cost of the reflective material is 10% of the total module cost, and the proposed work is economically viable due to waste reusability. In this work, three different non-biodegradable materials (polyvinyl chloride flex, thermocol, and aluminium foil) are reused as reflectors to improve their generation using Bi-FM. A detailed study is made using the waste materials as reflectors and the performance ratio is computed for different irradiation conditions observed across a day. The average performance ratio of thermocol and polyvinyl chloride flex is 20% and 8% respectively, higher than that of aluminium foil. Using a reflector made of PVC flex has a 3.59-year lifespan as compared to Bi-FM by employing a reflector made of aluminium foil. The deployment of non-biodegradable materials reduces the cost requirements. The proposed setup also increases the reusability of non-biodegradable waste materials as reflectors and improves the power generation of Bi-FM.

A comprehensive performance evaluation of bifacial photovoltaic modules: insights from a year-long experimental study conducted in the Canadian climate

Bifacial photovoltaic (PV) modules, capable of capturing solar energy from both sides of the cells, are becoming increasingly popular as their manufacturing costs approach those of traditional monofacial modules. Accurate estimation of their power generation capacity is essential for optimizing their use. This study evaluates a power production model for bifacial PV modules using local irradiance data from Razon+ in Sherbrooke, Canada, and Solcast irradiance data derived from satellite imagery and weather models. The model's performance was assessed throughout the year, with particular attention to the impact of snow coverage during winter. To address computational efficiency, the study evaluated ray tracing and a 2D view factor model, selecting the more time-efficient method. Experimental validation showed that, using local irradiance data, the model achieved Normalized Root Mean Square Errors (NRMSE) of 18.77%, 4.94%, 3.93%, and 6.22% for winter, spring, summer, and fall, respectively. With Solcast data, the NRMSEs were 22.76%, 15.32%, 14.72%, and 17.78% for the corresponding seasons. While the model performed satisfactorily in spring, summer, and fall, it was less accurate in winter. To enhance winter accuracy, the model incorporated snow coverage, using snow depth as a metric to detect snow on the front surface. This adjustment improved the accuracy by 51.1%.

Design Optimization of Large-scale Bifacial Photovoltaic Module Frame Based on FEM and RSM

Design Optimization of Large-scale Bifacial Photovoltaic Module Frame Based on FEM and RSM

Design and Analysis of a Hybrid Stand-Alone Microgrid

This research article presents a comprehensive investigation into the design, optimization, and performance analysis of a hybrid stand-alone microgrid for an industrial facility in Iraq at coordinates 36.51 and 43.99. The system consists of photovoltaic (PV) modules, inverters, a battery energy storage system (BESS), a generator, and AC loads. Leveraging the capabilities of PVsyst version 7.3.1, HOMER Pro version 3.14.2 and SAM version 2022.11.21 software tools, this study assesses the feasibility and functionality of the hybrid stand-alone microgrid. In this study, PVsyst software is used for detailed designing and analysis of a PV plant, and the PVsyst design file is then used in HOMER Pro software to optimize and design the proposed hybrid stand-alone microgrid, and for detailed performance analysis SAM software is employed. This paper also investigates the impact of ground clearance and ground albedo on the annual generation of bifacial PV modules at various tilt angles. Key findings include a promising normalized production rate of 4.53 kWh/kWp/day with a performance ratio of 0.815 and annual energy production estimates of 84.31 MWh (P50), 79.57 MWh (P90), and 78.24 MWh (P95) for monofacial PV modules, highlighting the system’s potential for renewable energy generation. Notably, this research demonstrates the hybrid stand-alone microgrid’s capacity to significantly reduce CO2 emissions, saving approximately 1811.6 tons over a 30-year period, thus contributing to sustainability and environmental conservation goals. Additionally, this study reveals operational challenges during the winter months, necessitating generator support to meet load demands. The successful installation and experimental validation of the hybrid stand-alone microgrid underscore its practical viability and its role in advancing clean energy solutions. This research provides valuable insights into hybrid stand-alone microgrid design, emphasizing its importance in ensuring reliable power supply and environmental stewardship.