Silicon heterojunction (SHJ) solar cell technology is one of the most promising PV technologies because of its high power conversion efficiencies, simple fabrication process and low manufacturing cost. The current world record efficiency of SHJ solar cell reaches up to 26.81%. SHJ solar cell produces the highest VOC over 750 mV among the c-Si solar cell technologies because of the excellent surface passivation provided by the few nanometers (i)a-Si:H layers. The objective of this thesis is to design and optimize the (i)a-Si:H bilayers that not only ensure excellent c-Si surface passivation quality but also allow less-resistive transport of charge carriers in SHJ solar cells. First, a database focusing on the microstructure properties of (i)a-Si:H layers was established. The database was compiled by systematically varying the PECVD deposition parameters of the pressure, power, and hydrogen dilution ratio. By means of FTIR (Fourier Transform Infrared Spectroscopy) characterizations, higher power and pressure were found to correspond with an increased absorption strength of high stretching modes (HSM), which indicated a higher R* and hydrogen content. These conditions led to the formation of a film that is rich in voids and hydrogen. Conversely, a denser a-Si:H film could be achieved by increasing the hydrogen dilution ratio, where the low stretching modes (LSM) were increased and became dominant. Overall, the built database showcases the possibilities to deposit (i)a-Si:H layers with microstructure factor spanning from 0.193 to 0.805. Subsequently, passivation optimization of the (i)a-Si:H bilayer on textured (111)-orientated c-Si wafers has been conducted. The optimal passivation is achieved by the combination of a 1 nm underdense i1 layer and a 9 nm dense i2 layer. The void-rich i1 layer with R* = 0.732 and the dense i2 layer with R* = 0.205 improved the passivation greatly from 2 ms to 7.5 ms, as compared to unoptimized STD1 layer (R* = 0.261) and STD2 layer (R* = 0.314). Despite various passivation qualities enabled by various bilayer structures, after hydrogen plasma treatment (HPT), the lifetime of all increased drastically to 17 ms, accompanied by increases FTIR-characterized in both H content and R*, which may indicate that passivation could be saturated after HPT. However, the passivation trend after VHF treatment was not clear. This could potentially be the instability in the PECVD deposition tool. Finally, (i)a-Si:H bilayers were implemented into FBC-SHJ solar cells, solar cells endowed with a bilayer consisting of X1 layer (R* = 0.382) and D2 layer (R* = 0.205) exhibited an average Voc of 715 mV. Combined with a denser D2 film, RS is reduced, helping to counteract the elevated series resistance associated with the incorporation of the X1 layer, contributing to the enhancement of the fill factor from 78.65% to 80.53%, although at the expense if a slightly lower VOC. The best-performing cell X1 + D2 with treatments gives achieved the highest efficiency of 23.23% (22.33 % on average) and the highest VOC of 717mV compared with an average of 22.24% and 711 mV of the ‘non-optimized’ standard cells fabricated. It is also observed that after treatments, the FF increases while VOC slightly reduces. However, the observed lack of a clear efficiency improvement when using the optimized bilayer as compared to the ‘non-optimized’ standard bilayer could be attributed to the instability of the PECVD tool, which primarily affects the lifetime of precursors, coupled with the relatively large error bars present in the results.

Grid congestion, which results from a larger demand for electricity transport than the available transport capacity, is a challenge in the Dutch energy transition. The growing pace of decentralized renewable energy development in less densely populated areas and the electrification of demand leads to congestion, which potentially hinders the connection of new renewable projects to the grid and slows down the energy transition. Due to the intermittent behaviour of renewable resources, the grid connection capacity is not used to its full capacity at all times. Cable pooling is introduced as a possible solution to congestion, allowing an existing and a new renewable resource to share a grid connection and improving the utlilisation of the current grid infrastructure. This thesis’ main objective is to develop a calculation framework to assist developers to evaluate the economic potential of a cable pooling location by optimizing the Net Present Value (”NPV”) of a shared grid connection, considering technical, regulatory, legal, and financial aspects. It aims to provide developers with a tool for making a preliminary decision on whether to continue development for a potential cable pooling location. The Dutch context is used to identify different grid connecting possibilities, different combinations of wind and solar to form a hybrid farm and different revenue streams. These are used in a methodology to find the optimal installed capacity of the added resource and the impact of on-site storage to one of the hybrid farms. The approach considers the influence of market prices on the technology specific cable pooling business case at an hourly level and accounts for long-term market developments. Other factors accounted for in the tool are the hourly export capacity, defined as the residual space after the export of the existing farm, land size and costs of installation. A case study of a solar farm oriented to the east-west is used to test the tool and draw conclusions on the potential of cable pooling for this case study. The additions of a wind and solar resource with either south or east-west generation all yield positive NPV values with the highest values seen for the wind addition. Sensitivity tests for technical and economic inputs show that the results are sensitive to weather data and various economic inputs, but the results of this case study are robust. The case study however considers a relatively large grid connection. Generalizing the results by considering a smaller grid connection shows the value of complementary production patterns. The impact on the cost-benefit framework by adding a battery is considered. The addition of a battery adds value by peak-shifting the produced energy, but not enough to cover the costs of the battery without any subsidy or alternative revenue streams. In conclusion, cable pooling shows potential for this case study, for different revenue streams and additions. The tool used to obtain the results can be tailored to different case studies and input scenarios and shows the economical attractiveness of a cable pooling location, based on the Dutch context. The Dutch context shows a promising potential for cable pooling as a method to deal with congestion, but not many projects are present yet. Considering different parties sharing one grid connection, coming to an agreement on the terms can form a hurdle. Therefore, the introduction of more transparent cable capacity calculations by DSOs and a separate subsidy for cable pooling projects could help incentivize the development of more cable pooling projects. The impact of developments such as the ”Use-itor-lose-it” on the cable pooling potential should be monitored closely. Other solutions to dealing with congestion, such as using the fault reserves, should not be disregarded.

This graduation report covers the process and outcome of developing and designing novel photovoltaic (PV) products for architectural and design applications. The project aimed to find innovative solutions for seamlessly integrating photovoltaics into architecture and design and thus contribute to sustainable building practices. With a hands-on, material-driven approach novel PV customization methods were developed and showcased with a demonstrator. Four concepts were proposed based on PV products made with customization methods that were developed during the project. One of these concepts was worked out into a working prototype. This demonstrated the aesthetic qualities of a novel PV coloring technology. The outcome of Solar Style formed the basis of the continued development and commercialization of PV products.

Global warming is currently being regarded as one of the most significant concerns in society. As globalnwarming is related to the greenhouse gases emitted from the current energy supply, there is a needbfor renewable energy sources. Solar energy is an energy source which has zero emissions and could in theory supply the energy demand. A solar cell is technology based on the photovoltaic effect, it converts solar irradiance, specifically the energy derived from photons, into electrical energy. Over the course of the development of photovoltaic technology, numerous variations of solar cells have been introduced. By IRTPV, it is anticipated that new and advanced concepts, especially the Tunnel Oxide Passivating Contact (TOPCon) solar cell, will come to dominate the solar market in the coming years. At ISCKonstanz, the primary objective is to develop solar cells that are feasible for industrial applications. The solar cell under investigation and exploration within the context of this particular thesis is referred to as TOPCon Rear Junction (TOPCon RJ), it differs from the well-documented TOPCon emitter Front Junction (FJ). The notable advantage lies in the fact that by placing the emitter at the RJ, the FSF can be lightly doped, thereby reducing Auger recombination. Another advantage is the possibility of increasing the metal pitch between the fingers, reducing the metal used. Even more, the TOPCon RJ doesn’t need the high temperature boron diffusion needed for TOPCon FJ, because of doping during APCVD deposition. Simulation results indicate that TOPCon RJ can achieve at least the same efficiency as TOPCon FJ. The TOPCon solar cell is developed on large area n-type Cz wafers, with a selective n++/n+ FSF of c-Si, a by APCVD inline deposited p+ poly-Si layer and screen printed silver contacts. The inline APCVD has fast processing as a major advantage. A comprehensive description of the TOPCon RJ solar cell structure will be provided. The solar cell’s parameters will be elaborated on, in order to characterize it. The report incorporates basic supportive solar physics. Various characterization methods will be expounded upon to offer a more comprehensive understanding of the research methodology. The research is divided into three parts: the development of the p+ poly-Si rear layer, the development of the n+ c-Si FSF, and the process of metallization. Good passivation for the individual layers were achieved and good contacting as well. However, viable cell results were not yet obtained. The research necessitates substantial further enhancements. Moreover, the presence of defects and damages significantly impacted the outcomes, lowering the reliability.

The population worldwide is growing rapidly which leads to an increase of the energy demand. Simultaneously, the established energy resources are being depleted and contribute negatively to the climate. The necessity for a sustainable and inexhaustible energy source, to deal with the increasing energy demand in an ecological friendly approach, will play a key role in the 21st century. One of the most predictable and inexhaustible renewable energy sources is the Sun. Nevertheless, changing weather conditions, like rain and clouds, winter and summer, result in daily and seasonal fluctuations. A reliable stand-alone solar system requires a profound storage method to tackle the daily and seasonal fluctuations that can potentially result in deficit or dumped energy. Generally, a battery bank is adopted in stand-alone solar systems, but the low energy density makes a battery bank not suitable as a seasonal storage method. A seasonal storage method can be implemented by the production and consumption of the chemical product hydrogen. Hydrogen has a high energy density compared to batteries (142 MJ/kg vs 0.95 MJ/kg), but the low round-trip efficiency prevents implementing hydrogen as a daily storage method. For a highly reliable and optimal sized stand-alone energy system, a combination of both a battery bank and the chemical product hydrogen are used as a profound storage method. The combined storage method can be used in times of excess and deficit energy. This results in a so called stand-alone hybrid PV-Electrolyzer-Battery-FC energy system. In this final thesis project a stand-alone hybrid PV-Electolyzer-Battery-FC energy system is modelled and optimized to determine the current and future feasibility, both technologically and economically, for residential utilization. A simulation model of the hybrid energy system is designed in TRNSYS. The model is optimized by minimizing the loss of load probability (LLP) and levelized cost of energy (LCOE) for the stand-alone hybrid PV-Electolyzer-Batter-FC energy system at residential level in TRNOPT. Several cases are optimized based on the electrical, heat and mobility demand. The used optimization method is a combination of particle swarm optimization (PSO) and Hooke-Jeeves optimization algorithms implemented by GenOpt. It is established that the proposed stand-alone hybrid PV-Electrolyzer-Battery-FC is technically feasible for the fulfillment of the annual electrical demand of a typical Dutch household. The feasible system size consists of 19 PV modules, battery capacity of 25.5 kWh and a tank volume of 1.24 cubic meters for a LCOE of 1.04 /kWh. If the future prices of the main components can be reduced to 0.01 €/Wp for PV, 0.01 €/Wh for battery and 0.01 €/W for electrolyzer and fuel cell the hybrid system can potentially reach a LCOE of 0.28 €/kWh. Reduction of the prices can be realized by large scale production, large scale implementation and technology maturity. In the end, a LCOE of 0.17 €/kWh can be realized by renewable energy systems if these future prices are realized and the following conditions are met: (1) fully covered roof area by PV modules and (1) the production, consumption and storage of hydrogen should be centralized to scatter the infrastructure costs over all the consumers. This can induce a so called hydrogen economy in the future, whereby the hydrogen gas can be the sustainable link between the increasing energy demand and the depleting fossil fuels.

Passivating contacts in the front-rear contacted c-Si solar cells enhances the device performance by quenching the contact recombination and enabling sufficient carrier transport. Tunneling oxide passi- vating contact (TOPCon) which consists of an interfacial oxide and a poly-SiO𝑥 layer is one of the most promising contact techniques in passivating both surfaces of the silicon wafer. However, the full area poly-SiO𝑥 layer is absorptive when it is applied at the front side which has become an efficiency limiting factor. In this project, an advanced local poly-SiO𝑥 passivating contact architecture is proposed and presented. The local poly-SiO𝑥 passivating contacts, so-called “poly-SiO𝑥 finger”, is deposited through a hard mask at predefined locations which will be only placed underneath the metal contacts. The formation of poly-SiO𝑥 finger and its application in the solar cells are discussed. First, a silicon wafer hard mask is fabricated by a lithography process followed by a KOH wet chemical etch-back process. Specified openings down to 38.7 𝜇m are established which isolate sections of the substrate for the poly-SiO𝑥 finger formation. P+ doped a-SiO𝑥 :H is deposited using PECVD with SiO𝑥 p+ diffused emitter commercial Cz wafers through the hard mask. By investigating the influence of deposition parameters during the PECVD, specifically the power and pressure, decent uniformity of the finger deposition is achieved. An optimized deposition condition of the doped a-SiO𝑥 :H is established for the poly-SiO𝑥 finger formation: an RF power source at 15 Watt, a chamber pressure of 1.5 mbar, and a substrate temperature of 180 °C. A narrow poly-SiO𝑥 finger with a width of 40.0 𝜇m has been demonstrated. Second, the passivation properties of the symmetrical samples are examined by varying the poly-SiO𝑥 and Al2O3 thickness for the hole carrier selective contacts. A full area p+ TOPCon and Al2O3 symmetric samples were coated on the textured diffused p+ surface with an n-type c-Si substrate to investigate the process parameters on the passivation properties. The optimal 𝑖𝑉𝑜𝑐 of p+ TOPCon samples is 662 𝑚𝑉 and a corresponding 𝐽0 of 156 𝑓 𝐴 𝑐𝑚2 which is obtained with a poly-SiO𝑥 thickness of 50 nm when annealed at 850 °C. The optimal thickness for the Al2O3 passivation layer is achieved by depositing a 20 nm thick layer followed by FGA, with an 𝑖𝑉𝑜𝑐 of 692 𝑚𝑉 and a 𝐽0 of 22.4 𝑓 𝐴/𝑐𝑚2. Finally, a process flowchart has been created to fabricate c-Si solar cells with the local p+ TOPCon on the front p+ diffused emitter and a full area n+ TOPCon on the rear side. A localized polished area is made by a poly-etch process for the alignment between the substrate and the pattern in the lithography mask. Using the ascertained parameters during the optimization, NAOS-SiO𝑥 combining with 50 nm-thick doped p+ a-SiO𝑥 :H fingers are applied on the p+ diffused surface and 100 nm-thick n+a-SiO𝑥 :H on the rear side. A annealing step is performed for the crystallization. A 20 nm-thick Al2O3 followed by a 75 nm SiN𝑥 layer are deposited on the front side and 100 nm SiN𝑥 layer is applied on the rear side. Lithography, wet chemical etch-back together with Al/Ag(front/rear) evaporation are utilized for solar cells metallization. The fabricated c-Si solar cells with poly-SiO𝑥 fingers has a champion efficiency with an efficiency of 7.91 %, with a 𝑖𝑉𝑜𝑐 of 562 𝑚𝑉, 𝑖𝑛𝑡 𝐽𝑠𝑐 of 34.7 𝑚𝐴 𝑐𝑚2 and fill factor of 40.5 %. The limited performance originates from the poor passivation in the poly-SiO𝑥 local contact area and severe 𝑖𝑉𝑜𝑐 drop after the metallization process. For further improvement, good performing c-Si solar cells by minimizing the recombination in the poly-SiO𝑥 local fingers contacts area and optimizing metallization steps are expected to be fabricated .

The electrical output of a solar panel can be optimised in several ways, through the inclusion of bypass diodes (BPDs) or to have a maximum power point (MPP) tracker or DC optimiser to ensure that the panel is always operating at its global MPP. However most of these systems have to be implemented externally to the panel. A new system, the active switching circuit was proposed as a means to actively sense shading and switch between three wiring configurations drawing inspiration from matrix converter theory. The active switching circuit prototype would operate for 16 solar cells arranged in a 4 x 4-cell solar panel and be able to change the wiring configuration of these sixteen cells using switches. The base unit of the solar panel is a substring composed of four solar cells in series and the circuit would switch between three wiring configurations. The shading would be measured through four current sense resistors and amplifiers, with one of these pairs in each substring and a differential operational amplifier system to measure the voltage across the strings. The current and voltage measurement helps determine the power output of the panel. A Simulink model of the system was first created and a panel with 4 x 4 solar cell arrangement ordered and then measurements made with shading to verify if the shading model was accurate. From these results a Simulink model for the active switching circuit was designed to test the theory of its functionality and if such a circuit could be controlled to switch between the three wiring configurations. The circuit was successfully built and was able to operate in its intended way.

Single junction solar cells have a theoretical efficiency limit of 33.1% due to spectral mismatch. To overcome this, multi-junction devices are generally fabricated with two or more junctions, so as to achieve better energy conversion efficiency by optimum spectral utilization. The c-Si bottom cell of a thin-film Si triple-/quadruple-junction device does not utilize the low energy photons (below 1.1 eV). The photons in the range of 0.7-1.1 eV, have an available current density of 15.9 mA/cm^2. A fraction of this current density would be large enough to not limit the output current of these thin-film Si-based multi-junction devices. Ge, belonging to the same group IV as Si and being heavier than it, forms weaker covalent bonds. Hence, it has a lower bandgap energy, making it the preferred choice of material. In this work, a low bandgap material such as a Ge-based absorber layer is fabricated that can be used in the bottom cell of a thin-film Si-based quadruple-junction device. This thesis will focus on the influence of a set of deposition parameters on the various properties of the Ge:H films. This will result in a set of Ge:H films from which a specific few are used as absorber layers to analyze the performance of a single-junction cell. The fabrication of the Ge:H films is carried out on a CASCADE setup which is based on the RF-PECVD technique. A processing range is identified to be in the range of 1-5 mbar pressure with RF powers ranging between 5-25 W for a fixed electrode distance of 20mm. nc-Ge:H are processed in the range of 20-25 W for pressures of 2 mbar and higher at a high dilution of 400. A strong correlation is found between the refractive index of the films and the presence of GeOx. The films with low refractive index possibly indicate a porous network with high void density show substantial oxygen contamination and vice-versa. Water vapour in the ambient is responsible for the oxidation. The oxygen contamination significantly impacts the properties of the films. The E04 optical bandgap increases with oxygen contamination which hinders the development of a low-bandgap absorber layer, while the Eact decreases to values as low as around 50 eV . Generally, the pre-exponential factor (sigma_o) decreases significantly by 1-5 orders of magnitude which outweighs the decrease in Eact, resulting in the decrease in dark conductivity by 1-3 orders of magnitude. Consequently, highest photo/dark conductivity ratios of 5-6 are obtained for these films. Amongst the films without oxygen contamination, the lowest E04 optical bandgap reported is 1.2 eV, with a Etauc bandgap of 0.93 and a photo/dark conductivity ratio around 3.4. Most of the single-junction cells processed at absorber layer thicknesses of 100nm and above show resistor-like behaviour. The substantially high values of Rs losses associated to the Rsh degrade the cell parameters significantly. Although, for low absorber layer thickness of around 50nm, the closest resemblance to a cell-behaviour is observed. Therefore, there is a scope for improvement with regards to processing of these single-junction cells.

The built environment contributes with 39% of the CO2 emissions in the world [3]. At the same time it is a sector that is expected to grow from US$10.9 trillion (2017) to US$12.9 trillion (2022) [4]. A sector with such an economic growth but with a negative environmental impact needs to innovate in order to reduce its carbon footprint. These are the reasons why, along this project, one of the most traditional components of the building façade will be re-designed. Glazing is a key component for the transformation of the built environment into a cleaner sector. Through glazing, radiation and natural light are received. With smarter window designs that make use of switchable films (films that change their transparency with different impulses) this reception could be done in a more efficient way. This can reduce the need of other artificial devices like air conditioning and light bulbs inside the buildings. Furthermore, if glazing is coupled with solar energy harvesting technologies like solar cells, an autonomous device can be created. A smart window that includes photovoltaic solar cells and an electrically switchable film is prototyped through this project. The selection of materials and construction of the window are explained through this document. Software modelling to recreate real life scenarios during a whole year are performed and the results are encouraging. An off-grid photovoltaic system that supplies energy to an electrically switchable film, all coupled in a glazing for building façade is technically possible, even in challenging environmental conditions.

In recent decades, there has been increasing concern about the impact of climate change on the earth. Various countries are actively developing sustainable energy technologies, of which solar cell is one of the new energy sources with the most attention. This thesis is based on poly−Si(Ox) cells consisting of SiOx/poly−Si(Ox) passivating contact. Various methods have been investigated to mitigate the TCO (IWO) deposition induced passivation degradation and to optimize the screen printing process. First, approaches to reduce the passivation degradation due to IWO deposition were explored. The power density and working pressure in IWO deposition were optimized. With utilizing 1.23 W/cm2 power density and 5×10−3 mbar working pressure, the 𝑖𝑉𝑂𝐶 degradation was reduced to 4.7 mV for 𝑛+ sample (NAOS-SiOx) and to 7.9 mV for 𝑝+ sample after deposition of 75 nm IWO. Besides, hydrogenated amorphous silicon and AZO were used as buffer layers for the 𝑝+ SiOx/poly−Si(Ox) samples, finding that they were effective in reducing sputtering damage. Then, the optimal post-annealing condition was investigated, which turned out to be vacuum annealing at 400 ◦𝐶 for 30 min, recovering the 49 mV and 60 mV 𝑖𝑉𝑂𝐶 for 𝑛+ sample (thermal-SiOx) and 𝑝+ sample, respectively. Based on the above experiments, the first cells were prepared with a maximum efficiency of 17.4%. Second, the existing screen printing process in the lab was optimized. The 0.37% organic solvent was added into the silver paste, reducing the viscosity of paste. The snap-off distance was changed to 0.02 mm in order to improve the continuity of printed grids. Moreover, the squeegee speed was optimized to 30 mm/s, limiting the spreading of silver paste to 57.3 𝜇m, much narrower than the initial spreading distance of 155.3 𝜇m. Finally, a batch of poly−Si(Ox) cells were prepared by applying the above various optimized conditions. The cell with optimized IWO and optimized screen printing process performed best with an champion efficiency of 18.9%.

Photovoltaic (PV) system yield prediction models are an important topic in the field of PV solar energy. An accurate prediction model could not only be used for optimising the PV system design, but is also expected to realise the yield potential of innovative PV technologies. In the next generation of PV technologies, one of the most promising concepts is the tandem solar cells. In recent years, these cells have impressed the solar industry by their rapid growth of the maximum power conversion efficiency (PCE). Since tandem solar cells are still at the lab phase, their yield potential under realistic conditions are an interesting field of study as well. However, the existing yield prediction models are not yet available for these tandem cells. In order to fill this gap, a prediction model developed in the Photovoltaic Materials and Devices (PVMD) group of TU Delft, called the PVMD Toolbox, has been adapted to be compatible with the tandem solar cells. In this thesis project, the version 3 of the Toolbox was developed. First the PVMD Toolbox was improved. Except monofacial c-Si cells and bifacial c-Si cell, it is now also available for tandem cells. One of the most promising tandem concepts, the perovskite/c-Si tandem, was taken as a reference tandem configuration integrated in the Toolbox. The Toolbox was also modified to take the influence of solar spectra into consideration and analyses cell performances individually. Secondly, the accuracy of the Toolbox was validated. A new figure of merit called 'relative total deviation' is put forward in this report, which calculates the ratio between the sum of deviations that each simulation introduces, and the total measured energy yield. When the electrical parameters were taken from the own measurements, the relative total deviation of simulation results was only 8.6%. Finally, the Toolbox was applied to two case studies. In the first study, it was found that the annual energy yield (AEY) of perovskite tandems can be increased up to 0.4% by optimising perovskite thickness for a certain location. The second case study compared the AEY of the tandem module and conventional c-Si module. Perovskite tandem module showed a high AEY, around 36% higher than that of the c-Si module. However, perovskite tandem had a lower specific yield as they are more sensitive to the spectral variation

Solar photovoltaic (PV) technologies offer a renewable alternative to power generation that is based on fossil fuels; however, to meet the rising demand in electricity a substantial amount of surface area is required. This will inevitably lead to the installment of these systems on agricultural land, subsequently intensifying the land-use conflict and threatening food security. To alleviate this, the use of agrophotovoltaic (APV) systems is investigated, which enable the simultaneous production of food and renewable energy. More specifically, the aim of this thesis is to determine the optimal topology for a medium-scale and stationary bifacial APV array, which is simulated under the climate of Boston, USA (42.37˚N, 71.01˚W). Irradiance modelling is performed with Radiance’s raytracing algorithm in combination with the daylight coefficient approach of Daysim and the Perez All Weather sky model, which is then coupled to the crop and electrical yield models to determine the overall land productivity. The modelling approach used is robust, while offering flexible manipulation of the array’s deployment configuration, which is crucial for multivariable optimization. The integration of bifacial PV offers various synergistic effects mainly due to the amplified ground irradiance necessary for crop growth. Owing to the decreased PV density and high elevation from ground, rear irradiance homogeneity and bifacial gain are enhanced. Widening of the row spacing resulted in a logarithmic increase of the incident ground irradiation, while the overall energy yield portrayed a negative exponential trend, which is attributed to the use of bifacial modules. East-west (E-W) facing and vertically installed topologies are better suited for shade intolerant species, or permanent crops since they permit additional light penetration, especially during the winter months. In contrast, south-north (S-N) facing and latitude inclined arrays lead to intense and non-homogeneous shading that is unfavorable for growth during winter or for crops that cannot acclimate to shade; nonetheless, energy yield and land equivalent ratio (LER) are significantly enhanced. Unlike previous studies where only conventional modules were examined, here the potential of a customized one is inspected to assess whether blueberries can grow effectively under shade. By integrating such a module in an E-W hinged PV topology, which is associated with the most optimal shading patterns and schedule, the agrivoltaic performance is optimized. In comparison to the reference case, the land’s productivity is increased by 59% with a reduction in electrical yield by a third. Through this holistic approach that incorporates a multi-scale sensitivity analysis, it is possible to achieve a spherical understanding of the limitations and potential synergies associated with the dual use of land, ultimately encouraging the sustainability of the agricultural sector.

Solar Photovoltaics has been a major source of clean renewable energy. Globally, PV has seen an exponential rise in installed capacity in the last decade. Better accessibility of PV technologies have created new opportunities for Urban applications. Building Integrated PV is one such promising application where PV technologies are used to generate power as well as function as a building element like facade. With dual function of PV modules, visuals plays a key role. This thesis explores one such technology ColorBlast™that utilises digital printed ceramic ink to give PV modules colour. Currently, various colour module technologies exist but most of them lack custamisability. A module which can be customised to have any desired colour to fit an application perfectly is in high demand. ColorBlast™is a colour photovoltaic technology developed by Kameleon Solar in the Netherlands. ColorBlast adds colour to a module by partially covering the surface of a module with digitally printed ceramic ink. ColorBlast modules can therefore be made with any colour including images. In thesis looks into evaluating the performance of ColorBlast modules with any desired colours including images. The most optimal way to cover the module with the ceramic ink to fit the application is explored. Furthermore, ways to improve both the visual and electrical performance are suggested. Visual performance of the module was found to depend upon the amount of surface covered by the ink and the colour of the ink. The most effective way to evenly distribute colour across the module was to print small hexagonal dots of area 2mm2-4mm2 and to spread it across the entire surface of the module such that the total printed area was always less than 50% of the surface of the module. By doing so, the module when viewed from a distance appears to have a homogeneous colour. This homogeneous colour is different to the printed colour and the relation between the two was evaluated. This concept was also extended onto modules with images. Different colour inks were found to have different transmission and reflection spectra. By measuring the transmission and reflection spectra for various inks and their combinations, the relation between the combined spectra and the proportions of primary constituents of the secondary and tertiary colours were determined. This was used to determine the change in incident light as seen by the cell. Further, it was observed that all of the transmitted light and 30% of the reflected light from the printed surface was incident on the surface of the module to generate power. The power production of a ColorBlast™module was predicted given the colour that was printed and the coverage factor. These were also extended to ColorBlast™with images and the predicted values were found to match the observed values with less than 1% error. When images are printed, each cell would produce different current and this would create hotspots and shorten the lifespan of the cell. Methods to reduce this by altering the current production of cells were discussed. The power loss for a ColorBlast™module was found to depend on the angle of incidence. The yearly energy production for a ColorBlast module in an installation at Helmond, Netherlands was estimated using and was found that ColorBlast modules in this application produce 28% less power in a year. Only the current production methods of ColorBlast with mono-crystalline Si cells and ceramic ink were studied. Further research on ColorBlast with different ceramic inks and different Solar cells will give a better insight on how to reduce power loss and improve visuals.

The on-field performance and lifespan of PV modules are affected by the interaction of numerous parameters, among which temperature, strain, and humidity. Among these parameters, only temperature is occasionally measured in PV installations, and such monitoring is often external to the module. This limits its use and does not provide accurate information on the conditions at cell level. The integration of different sensors on PV cells can improve the performance of PV devices and enable the early detection of faults and unwanted operating conditions, examples of which are PV-module delamination and the occurrence of hotspots, respectively. This thesis reports on the design, fabrication and testing of four types of sensors, as an initial step within the PVMD group towards sensor integration on PV cells. The devices considered for this work are the following: an aluminum-based resistive temperature sensor, a Boron-doped poly-silicon piezoresistive strain sensor, and two polyimide-functionalized humidity sensors – one capacitive, the other thermoresistive. Furthermore, these devices are combined into multi-sensing platforms with the aim to simultaneously sense sets of parameters (e.g., strain & temperature) to eventually compensate for their reciprocal interference. The results of the electrothermal characterization of the non-laminated temperature and strain sensors reveal an overall linear response of the devices, with an average TCR of around +3.75*10-3 °C-1 and -3.7*10-3 °C-1, respectively; this translates into a change in resistance of approximately 22.2-22.5% over the temperature range under study (30 °C-90 °C). Meanwhile, the characterization with a climate chamber of a fabricated capacitive humidity sensor shows a significant increase in capacitance: when relative humidity changes between 20% and 80% at 30 °C, the measured capacitance rises from 6.86 nF to 7.20 nF – equivalent to a 5% increase. Furthermore, capacitance measurements performed at constant humidity ratio and varying temperatures indicate a substantial cross-sensitivity of the humidity sensor under test, resulting in an approximately linear capacitance increase between 20 °C and 40 °C with an average regression slope of 10 pF/°C. Since the tested capacitive humidity sensor and piezoresistive strain sensor show a substantial response to temperature, temperature compensation is needed to ensure reliable and accurate measurements of both humidity and strain. To this regard, a simplified compensation based on the simultaneous interrogation of the resistive temperature sensor and capacitive humidity sensor is successfully performed, which highlights the importance of integrated multi-sensing platforms.

Among the advantages of crystalline silicon hetero-junction (SHJ) there is the possibility to use a thin c-Si wafer that is bendable, but still has a power conversion efficiency higher than commercially avail- able thin film (TF) modules. Nowadays, all the photovoltaic applications on curved surfaces use TF technologies, however their low power conversion efficiency requires a large area, which is not always available. Therefore, the entry of SHJ technology in the environment-integrated applications will de- crease the required PV area being a competitor of TF wherever the surface available is scarce and the the shape curved and not complex. A structure that would benefit the advent of SHJ modules is the infotainment spot, which is a solar- powered device that provides useful information and entertainment to the user through an interactive screen. Such a device was realized for the first time by Weeda et al. [1] in TUDelft, but the CIGS module that powered the device made the structure bulky, unattractive and unwieldy. In this thesis the experience of Kaneka Corp., which holds the world’s record of highest conversion efficiency for c-Si hetero-junction, was used to design the PV module that powers the stand-alone system of a new infotainment spot. In order to calculate the irradiation on the surface of the infotainment spot the Optical Model developed by Santbergen et al. [2] was used because allows flexibility in choosing the design and the location separately. However, this model does not include the surrounding, thus in this thesis three new ap- proaches to include the influence of the surrounding environment were proposed and validated through experimental measurements. Moreover, two of these new approaches have the possibility to study the irradiance also in indoor places. After that, its power was simulated knowing the irradiance values, the temperature of the PV module, computed with a thermal-energy balance, and other meteorological data. Lastly, a load profile was developed to simulate the system performance throughout the year. All these information served to find the best pair of number of SHJ cells to interconnect and battery capacity and basically it is a trade-off between system reliability and system size. The study indicated that in Osaka the infotainment spot would need 42 series connected half-cut solar cells that power a 12 푉 system with a storage capacity of 150 퐴ℎ in order to make the system completely autonomous and operable the whole year. The thesis ended with a working prototype of the Solar-Powered Infotainment Spot 2.0.

Implementing renewable energy generation and more sustainable consumption behaviour in the future inland shipping industry is necessary. Electrification of the inland shipping fleet leads to an increase in electrical energy demand on the consumption side. The generation of decentralized photovoltaic (PV) energy systems on board of general cargo vessels can be one solution to these challenges. To estimate the potential of these decentralized energy systems, accurate simulation models are needed. The objective of this research is to determine the photovoltaic potential of the Dutch general cargo inland shipping fleet. A method is developed to simulate the energy yield of moving general cargo vessels. The estimated energy yield is based on hourly power calculations. A difference is made between container and bulk vessels. This simulation model consists of a skyline, a vessel, an irradiance, a PV module temperature, and an energy model. In the skyline model, skyline profiles for 3036 waterway points are generated using LIDAR AHN3 height data. The waterways skylines are corrected for every vessel individually. In the vessel model, AIS (automatic identification system) data is used to simulate the sailing behaviour of 2746 vessels. In the irradiance model, the diffused, direct and ground reflection irradiance received by the PV panel is simulated. The diffused irradiance is calculated according to the Perez model. The PV module temperature is estimated according to the fluid-dynamic model. The additional air caused by the forward movement of the vessel and the water temperature is taken into account. Finally, the PV energy yield is calculated by the received irradiance, the suitable PV surface and the corrected PV module efficiency. An experiment is performed to validate the developed model, where a PV panel is installed on the vessel Harmonie. Equipment is installed to monitor Harmonie during one docking week and two sailing weeks. A co-variance linear regression model describes the relationship between the measured and the estimated PV power. According to the co-variance linear regression model, the P-value for the simulated PV power is below 0.05 and, therefore statistically significant. The outcome of the linear regression model is overestimated by 4 % with a 95 % confidence interval between 0.87 and 1.05. 740,958 PV panels can be installed on the general cargo fleet. Together, these panels have an installed peak power of 267 [MW] and an annual estimated PV potential of 230 [GWh]. The annual PV energy per unit area of a container vessel is 171 [kWh/m2 ] and for a bulk vessel 168 [kWh/m2 ]. The annual PV energy per installed power for a container vessel is 864 [Wh/Wp] and for a bulk vessel 852 [Wh/Wp]. When the outliers are removed from the annual specific power [Wh/Wp] dataset, the complete fleet can be modelled by a Weibull distribution. A t locationscale distribution is suggested when the outliers are not removed from the dataset. The average annual energy demand of a container vessel is 1440 [MWh], 7.17 % of this demand can be supplied by the PV panels installed on the vessel. Bulk vessels have an energy demand of 1350 [MWh] on average, of which the installed PV panels can cover 5.82 %.

One of the main problems with Instance-level Image Retrieval in video data is that for longer query videos or large amount of image queries, comparing all of the query images to every extracted frame is time-inefficient. This thesis aims to solve this problem by implementing Nearest Neighbour Search (NNS) algorithms and data compression methods, significantly reducing total comparison time. In most NNS use cases, the reference data is provided before reaching the user, allowing methods such as ANNOY or HNSW to partition the data beforehand. However, little research has been done into partitioning the data during run-time. In this thesis, the use of Nearest Neighbor Search and Data Compression methods are discussed for the purposes of matching a query image to a query video, both of which are provided at run-time. The result is an implementation of several state-of-the-art NNS and data compression methods in a system which, based on the amount of query images and the amount of extracted keyframes, selects the optimal comparison method to be used, as well as its optimal parameters if applicable.

This BSc Thesis is about the construction and control elements of the airplane group of the Solar Drone project. The project aims to improve the flight time of aerial vehicles, using solar energy. This document is delves into the possibility of applying solar cells to small model aircrafts. It outlines the challenges and solutions involved in building and controlling such a system. A ready-available airframe and fitting components will be used, in combination with a custom photo-voltaic and energy system, to create a prototype. The prototype takes the form of an unmanned aerial vehicle, making it capable of extended flights without requiring extensive monitoring. It will serve as a testing platform for the performance of the PV modifications done to the aircraft. Included in this document are simulations for calculating optimal solar panel placement inside a transparent wing with opaque ribs, in addition to software and hardware modifications that were required to make the other systems work well in combination with the custom energy system.

Solar photovoltaic cells are destined to become an important contributor in the renewable energy sector, also for small electrical systems inside buildings. They can be used to mobilise the electrical infrastructure, by providing an independent energy source for medium-consumption products, like decorative lighting. This thesis shows all aspects of designing and building an interior, solar powered lamp. First, the ideal position for indoor light harvesting has been investigated extensively, by recreating two typical Dutch rooms with 3D modelling software Blender. The light simulation tool RADIANCE was then used to compute the irradiance at various spots in the room, considering three standard sky types. Weather data from the KNMI was used to classify the sky conditions for every hour during two weeks in November, and the results were compared with pyranometer measurements, showing an error of 20% on a daily basis, and 5% over a five day period. The same simulation method was applied to predict the PV energy yield of four common solar cell technologies for a full year, for multiple room orientations and positions on a wall. Based on these results, three concepts were designed, corresponding to three specific room positions with different indoor light characteristics. Ultimately, one concept was chosen to be build as a prototype, with tailor-made, foil-to-foil laminated PV module, consisting of laser cut SunPower interdigitated back contact (IBC) cell technology. At standard test conditions, the measured short-circuit current was 2.37 A, with an open-circuit voltage of 21.5 V and a maximum power point of 35.9 Wp, resulting in an efficiency of 20.3%. Furthermore, a charge controller with maximum power point tracking algorithm was used to charge a 12V polymer lithium-ion battery pack. The combination of pyroelectric infrared (PIR) motion sensor detector and a light sensor module assures a conservative use of a 2.4 W strip of light emitting diodes (LED).

The installation of photovoltaic systems in the urban environment is becoming increasingly common. These photovoltaic systems are affected by a large fraction of reflected irradiance as well as partial shading. In a similar way these issues also have an important effect on bifacial photovoltaic power plants. Irradiance models that are able to take these issues into account are therefore gaining interest. For an accurate economic assessment of a PV system and the calculation of delivered power it is becoming very important to be able to accurately determine the irradiance on a PV system. Therefore there is a rising demand for accurate irradiance models that are able to take into account the effects that arise in complex geometric scenarios. The research in this thesis report aims to develop such a model which is able calculate the irradiance incident on bifacial modules and PV arrays in complex landscapes by combining the concepts of ray tracing and 3D view factors. The implementation of the proposed model decouples the irradiance simulation into independent blocks that allow to efficiently calculate the spectrally-resolved irradiance incident on a PV module. This decoupling makes the proposed model suitable for simulation of tandem devices in the near future. The developed simulation has been experimentally validated using measurements from the PVMD monitoring station and also in comparison with other sophisticated irradiance simulation models. Experiments with a large fraction of specular reflected irradiance showed a good match between the measured and the simulated irradiance. Validation over a longer time period was also performed for 3 different sensors on the PVMD monitoring station roof. The results show an overall low mean bias error between the measured and simulated irradiance for the time period between mid-August 2020 to mid-October 2020. The proposed model is able to model the irradiance impinging on a PV system in a complex urban environment using a decoupled structure and its performance is comparable to sophisticated existing ray tracing models. The performed simulations show a good match with the measurements for different situations. Further improvements are the implementation of higher order reflections, computational optimization and more extensive validation.