Comparative Study of Solar PV Power Plant Dimensionnement Connected to Network Based on Monofacial and Bifacial Modules

This article presents the results of comparative study of two PV solar modules technologies,namely monofacial and bifacial.This study main objective is to identify conditions and parameters that make it possible to obtain better energy and economic efficiency from one or other of two technologies.The study reason lies in revival observed on bifacial module in recent years where all the major manufacturers of PV solar panels are developing them where in a few years,this technology risks being at the same price as the monofacial solar panel with better efficiency.Economic indicator used is energy levelized cost(LCOE)which is function technology type,energy productivity,annual investment and operation cost.To achieve this,a 3.685 MWc solar PV power plant was dimensioned and simulated under Matlab for a 3.5 ha site with a 2,320,740,602 FCFA budget for monofacial installation,against 1,925,188,640 FCFA for 2.73 MWc bifacial installation.The LCOE comparative analysis of two technologies calculated over a period of 25 years,showed that plant with bifacial panels is more beneficial if bifacial gain is greater than 9%.It has further been found that it is possible to gain up to 40%of invested cost if bifacial gain reaches 45%.Finally,a loss of about 10%of invested cost could be recorded if bifacial gain is less than 9%.

Corrective Effect of the Angle of Incidence of the Magnetic Field Intensity on the Performance (Series and Shunt Resistances) of a Bifacial Silicon Solar Cell

This article presents a three-dimensional analysis of the impact of the angle of incidence of the magnetic field intensity on the electrical performance (series resistance, shunt resistance) of a bifacial polycrystalline silicon solar cell. The cell is illuminated simultaneously from both sides. The continuity equation for the excess minority carriers is solved at the emitter and at the depth of the base respectively. The analytical expressions for photocurrent density, photovoltage, series resistance and shunt resistance were deduced. Using these expressions, the values of the series and shunt resistances were extracted for different values of the angle of incidence of the magnetic field intensity. The study shows that as the angle of incidence increases, the slopes of the minority carrier density for the two modes of operation of the solar cell decrease. This is explained by a drop in the accumulation of carriers in the area close to the junction due to the fact that the Lorentz force is unable to drive the carriers towards the lateral surfaces due to the weak action of the magnetic field, which tends to cancel out as the incidence angle increases, and consequently a drop in the open circuit photovoltage. This, in turn, reduces the Lorentz force. These results predict that the p-n junction of the solar cell will not heat up. The study also showed a decrease in series resistance as the incidence angle of the magnetic field intensity increased from 0 rad to π/2 rad and an increase in shunt resistance as the incidence angle increased. His behaviour of the electrical parameters when the angle of incidence of the field from 0 rad to π/2 rad shows that the decreasing magnetic field vector tends to be collinear with the electron trajectory. This allows them to cross the junction and participate in the external current. The best orientation for the Lorentz force is zero, in which case the carriers can move easily towards the junction.

PV Capacity Evaluation Using ASTM E2848: Techniques for Accuracy and Reliability in Bifacial Systems

A variety of test methodologies are commonly used to assess if a photovoltaic system can perform in line with expectations generated by a computer simulation. One of the commonly used methodologies across the PV industry is an ASTM E2848. ASTM E2848-13, 2023 test method provides measurement and analysis procedures for determining the capacity of a specific photovoltaic system built in a particular place and in operation under natural sunlight. This test method is mainly used for acceptance testing of newly installed photovoltaic systems, reporting of DC or AC system performance, and monitoring of photovoltaic system performance. The purpose of the PV Capacity Test and modeled energy test is to verify that the integrated system formed from all components of the PV Project has a production capacity that achieves the Guaranteed Capacity and the Guaranteed modeled AEP under measured weather conditions that occur when each PV Capacity Test is conducted. In this paper, we will be discussing ASTM E2848 PV Capacity test plan purpose and scope, methodology, Selection of reporting conditions (RC), data requirements, calculation of results, reporting, challenges, acceptance criteria on pass/fail test results, Cure period, and Sole remedy for EPC contractors for bifacial irradiance.

Determination of the Base Optimum Thickness of Back Illuminated (n+/p/p+) Bifacial Silicon Solar Cell, by Help of Diffusion Coefficient at Resonance Frequency

The bifacial silicon solar cell subjected to a magnetic field, is illuminated by the back side by a monochromatic light in frequency modulation, with high absorption, At minority carriers diffusion coefficient resonance frequency, a graphical study of the expressions of recombination velocity on the rear side is carried out. The optimum thickness of the base of the bifacial solar cell is deduced for each resonance frequency.

AC Back Surface Recombination Velocity as Applied to Optimize the Base Thickness under Temperature of an (n+-p-p+) Bifacial Silicon Solar Cell, Back Illuminated by a Light with Long Wavelength

The bifacial silicon solar cell, placed at temperature (T) and illuminated from the back side by monochromatic light in frequency modulation (ω), is studied from the frequency dynamic diffusion equation, relative to the density of excess minority carriers in the base. The expressions of the dynamic recombination velocities of the minority carriers on the rear side of the base Sb1(D(ω, T);H) and Sb2(α, D(ω, T);H), are analyzed as a function of the dynamic diffusion coefficient (D(ω, T)), the absorption coefficient (α(λ)) and the thickness of the base (H). Thus their graphic representation makes it possible to go up, to the base optimum thickness (Hopt(ω, T)), for different temperature values and frequency ranges of modulation of monochromatic light, of strong penetration. The base optimum thickness (Hopt(ω, T)) decreases with temperature, regardless of the frequency range and allows the realization of the solar cell with few material (Si).

Bifacial Silicon Solar Cell Steady Photoconductivity under Constant Magnetic Field and Junction Recombination Velocity Effects

The paper reported a theoretical study on the photoconductivity of a bifacial silicon solar cell under polychromatic illumination and a constant magnetic field effect. By use of the continuity equation in the base of the solar cell maintained in a constant temperature at 300 K, an expression of the excess minority carriers’ density was determined according to the applied magnetic field, the base depth and the junction recombination velocity. From the expression of the minority carriers’ density, the photoconductivity of the solar cell was deduced and which allowed us to predict some recombination phenomena, the use of such solar cell in optoelectronics. The profile of the photoconductivity also permitted us to utilize a linear model in order to determine an electrical capacitance that varied with magnetic field.

External Magnetic Field Effect on Bifacial Silicon Solar Cell’s Electrical Parameters

The aim of this work is to present a theoretical study of external magnetic field effect on a bifacial silicon solar cell’s electrical parameters (peak power, fill factor and load resistance) using the J-V and P-V characteristics. After the resolution of the magneto transport equation and continuity equation of excess minority carriers in the base of the bifacial silicon solar cell under multispectral illumination, the photo-current density and the photovoltage are determined and the J-V and P-V curves are plotted. Using simultaneously the J-V and P-V curves, we determine, according to magnetic field intensity, the peak photocurrent density, the peak photovoltage, the peak electric power, the fill factor and the load resistance at the peak power point. The numerical data show that the solar cell’s peak power decreases with magnetic field intensity while the fill factor and the load resistance increase.

Back Illuminated N/P/P⁺Bifacial Silicon Solar Cell under Modulated Short-Wavelength: Determination of Base Optimum Thickness

A bifacial silicon solar cell under monochromatic illumination in frequency modulation by the rear side is being studied for the optimization of base thickness. The density of photogenerated carriers in the base is obtained by resolution of the continuity equation, with the help of boundary conditions at the junction surface (n+/p) and the rear face (p/p+) of the base. For a short wavelength corresponding to a high absorption coefficient, the AC photocurrent density is calculated and represented according to the excess minority carrier’s recombination velocity at the junction, for different modulation frequency values. The expression of the AC recombination velocity of excess minority carriers at the rear surface of the base of the solar cell is then deduced, depending on both, the absorption coefficient of the silicon material and the thickness of the base. Compared to the intrinsic AC recombination velocity, the optimal thickness is extracted and modeled in a mathematical relationship, as a decreasing function of the modulated frequency of back illumination. Thus under these operating conditions, a maximum short-circuit photocurrent is obtained and a low-cost bifacial solar cell can be achieved by reducing material (Si) to elaborate the base thickness.

An Improved Process for Bifacial n-PERT Solar Cells Fabricated with Phosphorus Activation and Boron Diffusion in One-step High Temperature

The bifacial n-PERT(Passivated Emitter Rear Totally diffused)solar cells were fabricated using a simplified process in which the activation of ion-implanted phosphorus and boron diffusion were performed simultaneously in a high-temperature process.For further efficiency improvement,the rear side doping level was regulated by applying two different implantation doses and the chemical etching step of boron rich layer(BRL)was added,and their effects on cell performance were investigated.The solar cells average efficiency reaches 20.35%with a bifaciality factor of 90%by optimizing rear side doping level,which can be explained by the decrease of Auger recombination.And it is further enhanced to 20.74%by removing the front side BRL due to the improvement of surface passivation and bulk lifetime.The improved fabrication process possesses the advantages of low complexity and cost and high cell efficiency and bifaciality factor which could provide a promising way to the commercial production of bifacial n-PERT solar cells.

Emitter layer optimization in heterojunction bifacial silicon solar cells

Silicon solar cells continue to dominate the market,due to the abundance of silicon and their acceptable efficiency.The heterojunction with intrinsic thin layer(HIT)structure is now the dominant technology.Increasing the efficiency of these cells could expand the development choices for HIT solar cells.We presented a detailed investigation of the emitter a-Si:H(n)lay-er of a p-type bifacial HIT solar cell in terms of characteristic parameters which include layer doping concentration,thickness,band gap width,electron affinity,hole mobility,and so on.Solar cell composition:(ZnO/nc-Si:H(n)/a-Si:H(i)/c-Si(p)/a-Si:H(i)/nc-Si:H(p)/ZnO).The results reveal optimal values for the investigated parameters,for which the highest computed efficiency is 26.45%when lighted from the top only and 21.21%when illuminated from the back only.

Impact of the Thicknesses of the p and p+ Regions on the Electrical Parameters of a Bifacial PV Cell

The present paper is about a contribution to the bifacial PV cell performances improvement. The PV cell efficiency is weak compared to the strong energy demand. In this study, the base thickness impacts and the p+ zone size influence are evaluated on the rear face of the polycrystalline back surface field bifacial silicon PV cell. The photocurrent density and photovoltage behaviors versus thickness of these regions are studied. From a three-dimensional grain of the polycrystalline bifacial PV cell, the magneto-transport and continuity equations of excess minority carriers are solved to find the expression of the density of excess minority carriers and the related electrical parameters, such as the photocurrent density, the photovoltage and the electric power for simultaneous illumination on both sides. The photocurrent density, the photovoltage and electric power versus junction dynamic velocity decrease for different thicknesses of base and the p+ region increases for simultaneous illumination on both sides. It is found that the thickness of the p+ region at 0.1 μm and the base size at 100 μm allow reaching the best bifacial PV cell performances. Consequently, it is imperative to consider the reduction in the thickness of the bifacial PV cell for exhibition of better performance. This reduced the costs and increase production speed while increasing conversion efficiency.

A Junction Electric Field Determination of a Bifacial Silicon Solar Cell under a Constant Magnetic Field Effect by Using the Photoconductivity Method

In this work, a theory based on the steady photoconductivity method, of a bifacial silicon solar cell under polychromatic illumination and a magnetic field effect, is presented. The resolution of the continuity equation in the base of the solar cell, allowed us to establish the expression of the minority carriers’ density from which the photoconductivity, the photocurrent density, the photovoltage and the solar output power as function of the junction recombination velocity and the applied magnetic field, were deduced. From I-V and P-V characteristics of the solar cell, optimal photovoltage and optimal photocurrent obtained at the maximum power point corresponding to a given operating point which is correlated to an optimal junction recombination velocity, were determined according to the magnetic field. By means of the relation between the photocurrent density and the photoconductivity, the junction electric field has been determined at a given optimal junction recombination velocity.

Characterizing Electrical Output of Bifacial Photovoltaic Modules by Altering Reflective Materials

Bifacial photovoltaic (PV) modules offer potentially enhanced power output over conventional modules due to their reported ability to harvest reflected radiation, increasing output up to an additional 30%. However, this enhancement has yet to be confirmed in the literature. This paper reports on a study comparing the power output of two nominally identical 700 W photovoltaic arrays utilizing equivalent system components and data logging equipment with varying configurations of reflecting geometries and materials. This study was undertaken at the Appalachian State University Solar Research Laboratory in Boone, NC, which houses two Class 1 pyranometers and pyrheliometer. PV power was reported under well-quantified irradiance conditions, including direct beam fraction. Six trials over six months (November-April) with varying reflective materials and geometries revealed that different reflecting materials did not significantly change power output. Mounting an array at 0° did adversely affect power output compared to the array at a 36° angle relative to horizontal using the same reflective material. Additional studies with varied materials, panel locations and geometries different from those tested may improve the power output.

Testing Bifacial PV Cells in Symmetric and Asymmetric Concentrating CPC Collectors

Bifacial PV cells have the capacity to produce solar electricity from both sides and, thus, amongst other advantages, allow a significantly increase both in peak and annual power output while utilizing the same amount of silicone. According to the manufacturer, the bifacial cells are around 1.3 times more expensive than the single-sided cells. This way, bifacial PV cells can effectively reduce the cost of solar power for certain applications. Today, the most common application for these cells is in stationary vertical collectors which are exposed to sunlight from both sides, as the relative position of the sun changes throughout the day. Another possible application is to utilize these cells in concentrating collectors. Three test prototypes utilizing bifacial PV cells were built. The initial two prototypes were built for indoor testing and differed only in geometry of the reflector, one being asymmetric and the other symmetric. Both prototypes were evaluated in an indoor solar simulator. Both reflector designs yielded positive electrical performance results and similar efficiencies from both sides of the cell were achieved. However, lower fill factor than expected was achieved for both designs when compared to the single cell tests. The results are discussed and suggestions for further testing are presented. A third prototype was built in order to perform outdoor evaluations. This prototype utilized a bifacial PV cells string laminated in silicone enclosed between 2 standard glass panes and a collector box with an asymmetric CPC concentrator. The prototype peak electrical efficiency and temperature dependence were evaluated. A comparison between the performance of the bottom and top sides of the asymmetric collector is also presented. Additionally, the incidence modifier angle (IAM) is also briefly discussed.

Numerical modeling of all-day albedo variation for bifacial PV systems on rooftops and annual yield prediction in Beijing

Bifacial PV modules capture solar radiation from both sides,enhancing power generation by utilizing reflected sunlight.However,there are difficulties in obtaining ground albedo data due to its dynamic variations.To address this issue,this study established an experimental testing system on a rooftop and developed a model to analyze dynamic albedo variations,utilizing specific data from the environment.The results showed that the all-day dynamic variations in ground albedo ranged from 0.15 to 0.22 with an average of 0.16.Furthermore,this study evaluates the annual performance of a bifacial PV system in Beijing by considering the experimental conditions,utilizing bifacial modules with a front-side efficiency of 21.23%and a bifaciality factor of 0.8,and analyzing the dynamic all-day albedo data obtained from the numerical module.The results indicate that the annual radiation on the rear side of bifacial PV modules is 278.90 kWh/m^(2),which accounts for only 15.50%of the front-side radiation.However,when using the commonly default albedo value of 0.2,the rear-side radiation is 333.01 kWh/m^(2),resulting in an overestimation of 19.40%.Under dynamic albedo conditions,the bifacial system is predicted to generate an annual power output of 412.55 kWh/m^(2),representing a significant increase of approximately 12.37%compared to an idealized monofacial PV system with equivalent front-side efficiency.Over a 25-year lifespan,the bifacial PV system is estimated to reduce carbon emissions by 8393.91 kgCO_(2)/m^(2),providing an additional reduction of 924.31 kgCO_(2)/m^(2)compared to the idealized monofacial PV system.These findings offer valuable insights to promote the application of bifacial PV modules.

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

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.

Influence and characteristic of shading on photovoltaic performance of bifacial modules and method for estimating bifacial gain

Bifacial PV modules have unique advantages in low-carbon building applications such as BIPV systems but often suffer from the shading problem resulting from higher surrounding objects or building facades.Point-blank quantitative studies of PV performance of bifacial modules operating in actual environments as affected by shading on PV cells are lacking due to the difficulties of analysis caused by the existing multiple variable factors.By constructing an experimental comparison system on a flat roof of a building,we experimentally tested and analyzed the comparative variation characteristics of PV performance of bifacial and mono-facial modules under different shading area fractions.The results show that from the viewpoint of photoelectric efficiency,the PV performance of both bifacial and mono-facial PV modules clearly varied with the shading fraction of PV cell in some linear rules,though it is difficult to find regularity from the perspective of output power which was also affected by dynamic solar radiation intensity.An abnormal phenomenon emerged that the photoelectric efficiencies of the bifacial modules with small shading fraction were higher compared to the case without shading.Based on the findings of the experimental results,a regression approximation method based on shading test results(RAST Method)is further proposed to analyze and calculate the bifacial gain of bifacial modules.In the case of the existing roof installation,the mean bifacial gains of the two bifacial modules with different inclination angles were 8.86%and 11.30%,respectively.

A review of bifacial solar photovoltaic applications

Bifacial photovoltaics (BPVs) are a promising alternative to conventional monofacial photovoltaics given their ability to exploit solar irradiance from both the front and rear sides of the panel, allowing for a higher amount of energy production per unit area. The BPV industry is still emerging, and there is much work to be done until it is a fully mature technology. There are a limited number of reviews of the BPV technology, and the reviews focus on different aspects of BPV. This review comprises an extensive in-depth look at BPV applications throughout all the current major applications, identifying studies conducted for each of the applications, and their outcomes, focusing on optimization for BPV systems under different applications, comparing levelized cost of electricity, integrating the use of BPV with existing systems such as green roofs, information on irradiance and electrical modeling, as well as providing future scope for research to improve the technology and help the industry.

Design of a new static solar concentrator with a high concentration ratio and a large acceptance angle based on bifacial solar cells

Solar concentrators are used in solar photovoltaic systems to lower the cost of producing electricity.In this situation,fewer solar cells can be used,lowering the overall cost of the system.The purpose of this article is to design,construct,install and test a stationary(non-tracking)concentrating system in Irbid,Jordan.Bifacial solar cells are used in the design.Two concentrator designs(with the same concentration ratio)are experimentally tested.Conc-A has a parabolic shape in the lower part but flat reflecting walls,whereas Conc-B has a standard compound parabolic shape in all parts.The receiving solar cells are arranged in three distinct positions in each concentrator.The results reveal that the output power from both concentrators is affected by the placement of the receiving solar cells within the concentrator.It has also been found that concentrators with flat reflecting walls perform better than those with parabolic reflecting walls.Conc-A’s power collection is~198%greater than that of a non-concentrating device.When Conc-B is used,the increase in power is~181%.

A software-based approach in designing a rooftop bifacial PV system for the North Hall of Residence, IUT

Bifacial rooftop photovoltaic panels appear to be an excellent means of power generation in this era of urbanization,especially for land-limited countries like Bangladesh.This paper presents a software-based approach to design and simulate a bifacial solar-panel-based energy model on the rooftop of the North Hall of Residence of the Islamic University of Technology,Gazipur.This vertically mounted model investigates the feasibility and applicability of such an energy model in a university residence,situated in a load-shedding-prone area.Hence,three prominent software platforms,namely PVSOL,PVsyst and System Advisor Model(SAM),are brought into action and rigorous simulations are performed for three different orientations;promising outcomes are observed in terms of annual energy yield,bifacial gain(BG)and consumption coverage of the grid and PV model.The annual energy demand of the North Hall is~444733.5 kWh.The three orientations can generate annually 92508.62,94643.48 and 86758.94 kWh,respectively.Hence,it is evident that the proposed orientations can supply almost 19-21%of the site’s annual demand.Monthly BG analysis shows an overall increase in energy gain of 13%,15.6%and 6%for Orientation-1,Orientation-2 and Orientation-3,respectively.A rigorous comparative analysis and deviation analysis among the software results has been accomplished to gain more insight into the feasibility of the proposed system.Thus,we have focused on a detailed software-based estimation of energy production for different orientations of the PV panels,considering several factors,which will provide prior knowledge and assessment before going for hardware implementation in the future.