Malgré le bénéfice apparent des modules bifaces, cette technologie souffre toujours d'un manque de visibilité sur les gains en performance qu'elle apporte. Dans cette thèse, nous étudions le cas de modules bifaces verticaux intégrés sur une façade et nous évaluons plusieurs architectures de modules spécifiques aux contraintes électriques et optiques des applications bifaces. Nous avons mis en place une méthodologie d'évaluation des performances électriques annuelles de modules bifaces basée sur trois outils : un dispositif de caractérisation en double éclairement au simulateur solaire, un banc de test modulable en environnement extérieur et son modèle optique avec un logiciel de tracé de rayons. Les résultats expérimentaux obtenus à court terme dans différentes configurations du banc ont permis de valider notre modèle optique. Ainsi, les performances annuelles de l'application façade verticale à échelle réduite ont pu être maximisées suivant les paramètres importants de l'application et du module. En particulier, les avantages d'une architecture à cellules découpées, à interconnexion en parallèle et à verres texturés ont été évalués séparément vis-à-vis des pertes résistives qui surviennent en double éclairement et du rayonnement souvent non-uniforme et diffus incident sur la face arrière du module. Ce travail à échelle réduite a permis de dresser des perspectives pour un module de taille réelle et d'initier des études à l'échelle du système biface. / Despite the apparent benefits of bifacial modules, their application still suffers from a lack of visibility on the performance gain that they can actually provide. In this thesis we consider the specific application of vertically oriented bifacial modules, notably for facade integration. We also consider several innovative module architectures to work around some of the electrical and optical constraints of bifacial modules. We have developed a methodology to evaluate the annual electrical performance of bifacial modules based on three tools. Firstly, a double illumination characterization setup is used in a solar simulator for comparing module architectures. Then, a reduced scale outdoor test bench allows us to evaluate bifacial module performance in a variety of configurations. Finally, a ray-tracing model validated with short-term outdoor data leads to the annual electrical performance. This methodology allowed us to find optimal performance according to the most important parameters of application and module. Specifically, a module architecture using half-cut cells, a parallel cell interconnection and textured glasses have been analysed with respect to their influence on the resistive losses which occur in double illumination as well as to their influence on the effect of non-uniform and diffuse irradiance on the backside of the module. This work enabled us to propose real size module architectures and to launch studies at the bifacial system level.

This thesis work aimed to develop solar Photovoltaic (PV) powered smart street post. The post was set to serve on highways for wild animals’ detection and warn vehicles of possible crossings. The main aim was to design reliable standalone PV system via PVSyst software and experimenting four different PV technologies including a bifacial module under. Another aim was to select and develop the hardware and software terms of the smart street pot. Radar sensor and analog to digital (A/D) data acquisition (DAQ) card were set to be used for the motion detection. RF wireless communication module was used for communicating with nearby posts to send data and trigger warning light emitting diodes (LED) sign. A Raspberry Pi microcontroller was programmed to control the operation of the street post through processing the signal from radar sensor and communicating with nearby posts. The PV system design included generation of street post’s daily profile, sizing and selection of the components of the system including the module, battery, charge controller and power stage circuit. The later was designed to provide suitable voltage level and interface for the loads connected. PVSyst model was built and set to be located in Ulm, Germany. The design parameters were set, and different set of orientations were tested for each module. The simulation results showed bifacial module delivered a reliable PV system in case of south and south-east orientation and achieved better performance in other orientations in comparison to the other PV modules implemented. Due to limitations in PVSyst software the results provided had an overall uncertainty of 5%. The microcontroller was able to process the data from the radar sensor and DAQ card and perform fast Fourier transform (FFT). However, further processing of motion detection was complex to be included in the thesis work. The radar sensor and DAQ card provided signals with uncertainty of ± 3.4 mV. The RF wireless communication module transmitted signal over various ranges up to 150 m with time delay of 500 ms.

The following Master Thesis will talk about a C-PV prototype using bifacial PV technology, based on the Solarus Collector. The Solarus Collector consists in two PV cells built on a metallic receiver, where there are some water channels flowing through it, allowing to cool down the PV cells, thus increasing their efficiency. The collector also presents a reflector to provide irradiance to the back part of the receiver, where the other PV cells are located. The new prototype will present bifacial PV cells but not a metallic receiver. This construction aims to reduce the price of the receiver, but will not have a system to cool down the solar cells. This Master Thesis will be developed in the Solarus facilities, in collaboration with the Solarus members. In order to grasp an idea of this prototype, two main procedures will be done. Regarding the bifacial technology, a bifacial PV module will be measured under different conditions, depending on which sides can be illuminated or shaded. On the other hand, a thermodynamic simulation will be carried out on different geometries of the reflector and receiver, in order to figure out the evolution of the temperatures on the new prototype. This simulation will be done with a finite element method, widely known in this applications. The results will show several problems concerning this prototype. Although the measurements of the bifacial PV module will result beneficial and informative, the problem with the temperature will tend to back down this prototype. The lack of some system to cool down the bifacial cells will imply that the receiver could reach unacceptable temperatures. This hypothesis will be drawn under some specific conditions, so they will not be completely devastating to the idea of using bifacial cells, but perhaps a different approach should be used in case it is desired to continue this work.

This study aims to develop a simulation and optimisation tool for bifacial photovoltaic (PV) modules based on the open-source code OptiCE and evaluate dynamic and static albedo impact on a bifacial PV system. Further, a review of the market price development of bifacial PVs' and an optimisation to maximise energy output was conducted. Two case studies with bifacial PV modules, a single-axis tracker in Denver, USA, and a vertical and a tilted system installed at a farm outside Västerås, Sweden, were analysed in this study. The results showed that an hourly dynamic albedo value could provide more accurate simulation results of the rear side irradiance for the bifacial single-axis tracker than a static albedo value. The developed model showed an R2 accuracy of 93% and 91% for the front and rear sides, respectively, when simulated with an hourly albedo value for the bifacial single-axis tracker system. The optimisation was based on weather data from 2020. The results showed that the tilted reference system could increase its energy output by 8.5% by adjusting its tilt from 30° to 54° and its azimuth angle from 0 to -39°. In contrast, the vertical system would increase its energy output by 2.1% by rotating the azimuth angle from -90° to -66°. Conclusions that could be drawn are that bifacial PV price has closed in on the high-performance monofacial PV price the last five years and may continue to decrease in the coming years. Further, it was concluded that detailed dynamic albedo values lead to more accurate simulations of the ground-reflected irradiance. The availability of measured albedo data at the location is essential when the ground-reflected irradiance stands for a significant share of the irradiance. It was determined that during 2020 the optimal configurations of a vertical and tilted bifacial PV system in Västerås would save 11 300 SEK by consuming self-produced electricity and earn 11 600 SEK from selling the surplus of electricity for the farm outside Västerås.

No description available.

<div>In a world of ever-increasing demand for energy while preventing adverse effects of climate</div><div>change, renewable energy has been sought after as a sustainable solution. To this end,</div><div>the last couple of decades have seen an advancement in research and development of solar</div><div>photovoltaic (PV) technology by leaps and bounds. This has led to a steady improvement</div><div>in the cost-effectiveness of solar PV as compared to the traditional sources of energy, e.g.,</div><div>fossil fuels as well as contemporary renewable energy sources such as wind and hydropower.</div><div>To further decrease the levelized cost of energy (LCOE) of solar PV, new materials and</div><div>technologies are being investigated and subsequently deployed as residential, commercial, and</div><div>utility-scale systems. One such innovation is called bifacial PV, which allows collection of</div><div>light from the front as well as rear surfaces of a flat PV panel.</div><div><br></div><div>In this thesis, we present a detailed investigation of bifacial solar PV farms analyzed across</div><div>the globe. We define the problem, explore the challenges, and collaborate with researchers</div><div>from academia and the PV industry to find a novel solution.</div><div><br></div><div>First, we begin by developing a multi-module computational framework to numerically</div><div>model a utility-scale bifacial solar PV farm. This requires integrating optical, electrical,</div><div>thermal, and economic models in order to estimate the energy yield and LCOE of a bifacial</div><div>PV system. The first hurdle is to re-formulate the LCOE so that the economist and the</div><div>technologist can collaborate seamlessly. Thus, we re-parameterize the LCOE expression</div><div>and validate our economic model with economists at the National Renewable Energy Lab</div><div>(NREL).</div><div><br></div><div>Second, we extend the existing optical and electrical models created for stand-alone</div><div>bifacial PV panels to models that can simulate a large-scale bifacial solar PV farm. This</div><div>brings the challenge of mathematically modeling solar farms and light collection on the rows</div><div>of PV panels elevated from the ground by taking into account the mutual shading between</div><div>the rows, reflections from the ground, and elevation-dependent light absorption on the rear</div><div>surface of the PV panels from several neighboring rows. Next, we integrate temperaturedependent</div><div>efficiency models to take into account the effects of location-dependent ambient</div><div>temperature, wind speed, and technology-varying temperature coefficients of the solar PV</div><div>system in consideration.</div><div><br></div><div>Third, we complete the comprehensive modeling of bifacial solar PV farms by including</div><div>two types of single-axis tracking algorithms viz. sun-tracking and power tracking. Using these</div><div>algorithms, we explore the best tracking orientation of solar farms i.e., East-West tracking</div><div>vs. North-South tracking for locations around the world. We further find the best land type</div><div>suitable for installation of these E/W or N/S tracking bifacial solar PV farms.</div><div><br></div><div>Fourth, we reduce the computation time of numerical modeling by utilizing the advantages</div><div>of machine learning algorithms. We train neural networks using data from the alreadybuilt</div><div>models to emulate the numerical modeling of a solar farm. Amazingly, we find the</div><div>computation time reduces by orders of magnitude while accurately estimating the energy</div><div>yield and LCOE of PV farms.</div><div><br></div><div>Fifth, we derive, compare, and experimentally validate the thermodynamic efficiency</div><div>limits of photovoltaic-to-electrochemical energy conversion for the purpose of storing solar</div><div>energy for future needs.</div><div><br></div><div>Finally, we present some new ideas and guidelines for future extensions of this thesis as</div><div>well as new challenges and problems that need further exploration.</div>

Solar parks are increasingly getting a larger market share of PV installations over the world, and have for the last couple of years managed to establish itself in the Swedish market. The market has for a long time been known for its decline in module prices, which has allowed an emergence of more efficient PV-techniques such as one-axis trackers and bifacial modules. Bifacial modules use the backside of modules for improved utiliziation of incoming light, while one-axis trackers have the ability to track the sun in order to maximise light absorption. These innovations have now caught the interest of companies willing to invest in large-scale PV-farms, where efficient land use is highly regarded. The aim of this thesis was to examine how bifacial modules and one-axis trackers perform in terms of system performance and profitabilty if implemented in 'Solpark Fyrislund', a solar park owned by Vasakronan AB. This was done by modelling and simulating cases in which said techniques were incorporated. The data was later used to estimate profitabilty of each investigated case. Results showed that the highest system performance and profitability was achieved by installing bifacial modules on the site. One-axis trackers are currently too expensive, require higher maintenance and has a higher demand for land, resulting in its profitability not being justified. It was also found that the current configuration could be optimized further for higher profit, by slightly reducing the pitch as well as increasing the tilt of the existing modules. The study should be followed up by further investigating the use of backtracking for one-axis trackers. Said innovations should also be more established in the Swedish market so that CAPEX- and OPEX prices become more accessible.

Les travaux présentés dans cette thèse consistent à concevoir des modules à haut rendement et à bas coûts. Des modules intégrés réalisés à partir de sous-cellules découpées ont été réalisés. Ces sous-cellules sont inspirées de la technologie PERC. La réduction du coût de production en simplifiant le procédé de fabrication et en diminuant la quantité de matériaux utilisés a été étudiée. L’augmentation des rendements a été observée en ouvrant la face arrière des cellules, ce qui leur confère la bifacialité, et en utilisant des moyens performants pour la réalisation des émetteurs. Dans un second temps, l’augmentation de la puissance des modules a été étudiée en s’inspirant de l’i-Cell développée par la société S’Tile pour réduire fortement les pertes résistives traditionnellement observées dans les modules classiques. La même étude a été réalisée à partir de cellules IBC spécialement conçues pour être découpées en sous-cellules et ainsi assemblées en modules. Ces cellules ont été développées pour être compatibles avec des procédés industriels de production de masse, permettant de réduire le coût de production par rapport à des cellules IBC conventionnelles. Les sous-cellules obtenues après découpe ont été connectées pour obtenir des modules photovoltaïques bifaciaux permettant l’obtention de hauts rendements. De cette manière, deux voies possibles sont explorées pour l’amélioration des rendements et la diminution des coûts des modules photovoltaïques. / The work presented here is aimed to produced high-efficiency, low-cost photovoltaic silicon solar modules. Integrated modules have been carried out from laser-cut sub-cells. These cells have been produced using the PERC cell technology. The reduction of production costs have been studied by simplifying the manufacturing processes and by decreasing the quantity of materials used. An increase in efficiency has been observed by opening the rear side of the cells, making them bifacial, and by using advanced means in order to realize the cell emitters. The increase of produced power has been studied by using sub-cells in order to reduce the resistive losses measured in standard modules. The same study has been carried out with IBC solar cells. These cells have been designed to be separated in sub-cells by laser scribing, and to be produced with means compatible with mass production only, thus decreasing the cost. The sub-cells obtained after laser scribing have been connected in order to obtain bifacial photovoltaic modules producing high electrical power. In this way, two possible paths towards high efficiency and low cost modules have been studied.

In this study, we investigated the effect of electrolyte composition, photoanode thickness, and the additions of GuSCN (guanidinium thiocyanate), NMB (N-methylbenimidazole), and SiO2 on the photovoltaic performance of DSSCs (dye sensitized solar cells). A bifacial DSSC is realized and irradiated from front and rear sides. The devices give maximum photovoltaic efficiencies for 70% PMII (1-propyl 3-ethylimidazoliumiodide)/30%(EMIB(CN)4)(1-ethyl-3-methyl-imidazolium tetracyano borate) electrolyte composition and 10 &mu / m thick photoanode coating which is considered to be the ideal coating thickness for the diffusion length of electrolyte and dye absorption. A significant increase in the photocurrent for DSSCs with optimum molarity of 0.1 M GuSCN was observed due to decreased recombination which is believed to be surface passivation effect at photoanode electrolyte interface suppressing recombination rate. Moreover, optimum NMB molarity was found to be 0.4 for maximum efficiency. Addition of SiO2 to the electrolyte both as an overlayer and dispersed particles enhanced rear side illuminated cells where dispersed particles are found to be more efficient for the front side illuminated cells due to additional electron transport properties. Best rear side illuminated cell efficiency was 3.2% compared to front side illuminated cell efficiency of 4.2% which is a promising result for future rear side dye sensitized solar cell applications where front side illumination is not possible like tandem structures and for cells working from both front and rear side illuminations.

Solar energy market has been rapidly growing in Sweden over the past few years. Älvdalen municipality in central Sweden is investigating the possibility of installing a utility-scale solar power plant. In the present work, we investigate technical design and economic viability of a utility-scale solar power plant in Älvdalen. Several photovoltaics (PV) designs on a 6.6-hectar land are modeled and analyzed. The installation capacity depends on design parameters, such as inter-row spacing distance and orientation.PVsyst simulation tool is used to model several PV system configurations, consisting of both mono- and bifacial PV modules. An extensive sensitivity analysis is performed to get a deep understanding of different design parameters and their effects on performance and production yield of the plant.For PV systems consisting of monofacial PV panels, a set of parameters is investigated, namely, tilt angle of PV arrays, space between rows of the plant. It is observed that an optimized design requires a careful consideration of the two parameters, since they considerably affect the amount of self-shading (shading of PV rows on each other).The optimum design generates more than 5000 MWh electricity annually.Bifacial configurations are designed in two forms: tilted (south or south-east facing) and vertical (east-west oriented). Tiled bifacial systems are basically similar to the monofacial ones. A comparison between the two systems shows that the bifacial gain is between 3 % to 10 %, depending on the tilt angle, inter-row spacing, and PV array height above the ground. Electricity generation per surface area of the vertical east-west bifacial configuration is significantly lower compared to the others and therefore, it is only economically viable together with other land applications, such as agricultural usage.Economical evaluation indicates that for the optimum design the levelized cost of energy (LCOE) is 0.67 SEK/MWh and 0.72 SEK/MWh for monofacial and bifacial system, respectively. Such financial figures are subject to change, depending on the design and financial parameters.