To be able to mitigate the climate change and disasters that will come with it and to ensure economic growth, there is a need for change. A good start is more renewable energy and less harmful emissions. It is known that solar energy is sustainable and made from an endless source, the sun. However, it is not known how much impact the photovoltaic solar panels have through its entire lifecycle, from extraction of raw materials to End of Life management. This study has investigated photovoltaic solar panels' full life cycle to see how sustainable they really are. Including where the biggest opportunities for improvement of environmental, financial and social sustainability within the value chain is found. The results have been obtained by conducting a literature study, interviews with people with expertise of different parts of the value chain and finally calculations have been made to compare and visualize the findings. Two main ways to improve the PV panels’ negative impact in terms of environmental, financial and social sustainability have been established. Firstly, the study suggests the importance of implementing advanced recycling within the value chain. Recycling a high percentage of materials in the PV panel, and reusing the recovered material in production will decrease the energy consumption and harmful emissions significantly, alongside increasing circularity of critical materials and bring both financial and social benefits. Secondly, moving the better part of the production to Europe from China would also decrease the negative impact of the PV panels, especially the environmental and social impact, the study could however not find sufficiently good arguments for financial improvement to move the production to Europe. To be conclusive, this subject would need further studies. / För att kunna lindra klimatförändringar och de medföljande katastroferna och säkerställa den ekonomiska tillväxten finns det ett stort behov av förändring. En bra start är att använda mer förnybar energi och som bidrar till färre skadliga utsläpp. Det är känt att solenergi är hållbart med bränsle från en oändlig källa, solen. Det är emellertid inte känt hur stor påverkan solcellspanelerna har under hela dess livscykel, från utvinning av råvaror till dess panelens liv är över. Denna studie har undersökt solcellspanelernas hela livscykel för att se hur hållbara de egentligen är. Studien har även studerat var de största möjligheterna för förbättring av miljömässig, finansiell och social hållbarhet inom värdekedjan finns. Resultaten har erhållits genom att genomföra en litteraturstudie, intervjuer av personer med expertis inom olika delar av värdekedjan och slutligen har beräkningar gjorts för att jämföra och visualisera resultaten. Två huvudsakliga sätt att förbättra solpanelernas negativa påverkan när det gäller miljömässig, ekonomisk och social hållbarhet har identifierats. För det första föreslår studien vikten av att implementera avancerad återvinning inom värdekedjan. Återvinning av en hög andel material i solcellspanelen och återanvändning av det återvunna materialet i produktionen kommer att minska energiförbrukningen och skadliga utsläpp avsevärt samt förbättra cirkuläriteten av kritiska material och medföra både ekonomiska och sociala fördelar. För det andra skulle förflyttning av den större delen av produktionen till Europa från Kina också minska de negativa effekterna av solcellspaneler, särskilt de miljömässiga och sociala effekterna, studien kunde dock inte hitta tillräckligt med goda argument för att en förflyttning av produktionen till Europa skulle leda till en ekonomisk förbättring. För att detta ska vara avgörande skulle detta ämne behöva ytterligare studier.

The solid-state dye sensitized solar cell (SDSC) is an emerging photovoltaic technology which promises inexpensive materials, roll-to-roll processing, and a stable architecture. In this thesis, I seek to enhance electronic transport in order to enable thicker devices and yield higher power conversion efficiencies. I adopt a multipronged approach to advance three aims, employing analytical, computational, and experimental methodologies. First, I generalize existing models of the dye sensitized solar cell (DSSC) to allow simple parameter fitting of real devices and to account for previously ignored electronic processes. In Chapter 3 and Chapter 4 I present a nondimensional model capable of fitting real devices and simulating transient behavior without extensive material knowledge. Subsequently in Chapter 5, I introduce a novel three-dimensional model which incorporates electronic drift. Second, in Chapter 4 I critically assess a widespread method of measuring the charge collection efficiency, the summary metric that describes the efficacy of charge transport in the SDSC. I discover that the conventional method is inaccurate for values of the collection efficiency below 90% because of large experimental error and an intrinsic inaccuracy in applying a transient method to measure a steady-state parameter. Third, I aim to increase the rate of charge transport by employing new materials and nanostructures in the place of conventional nanocrystalline TiO2. In Chapter 5, I present evidence of faster transport and enhanced efficiency in flexible SnO2 nanowire SDSCs, ZnO nanowire SDSCs, and the first viable SnO2/P3HT SDSC, where photoanode and hole transporter have been replaced with higher mobility materials. Finally, in Chapter 6, I investigate use of TiO2 mesoporous single crystals (MSCs) with high surface area and extended crystallinity. After demonstrating the viability of MSCs in SDSCs, I examine enhanced transport caused by the background doping effect of thermal treatment. Together, the progress achieved toward diverse and ambitious goals advances the field and delineates routes to future progress for SDSC development.

La forte dépendance du pétrole et les contraintes écologiques et environnementales obligent de nombreux constructeurs automobiles à développer des programmes de recherche importants dans le développement des véhicules électriques (VEs) et des infrastructures associées. Les batteries embarquées dans les VEs peuvent être rechargées par le réseau électrique ou par une autre source d'énergie renouvelable. Dans ce contexte, cette thèse a pour but d'étudier un système de recharge de VEs à partir de l'énergie solaire. Pour ce faire, une étude de dimensionnement du système a été proposée afin d'évaluer les besoins énergétiques des VEs et déterminer les quantités d'énergie nécessaires pour les propulser. Les éléments principaux du système ont été dimensionnés. Il s'agit de panneaux photovoltaïques, de la batterie de stockage (au plomb), et de la batterie de traction (Li-ion). A partir de cette étude de dimensionnement, nous avons pu déterminer la puissance et la quantité d'énergienécessaire pour propulser un VE compte tenu de ses caractéristiques. Pour étudier le comportement des différents éléments du système et analyser leur adéquation avec le processus de recharge, une étude de modélisation a été réalisée, et chaque élément est représenté par un modèle mathématique. L'analyse et la comparaison des résultats obtenus (résultats de simulation et résultats expérimentaux) ont permis de valider les modèles proposés. De même, cette étude de modélisation a permis de valider le choix des composants du système de recharge. Dans le but de gérer efficacement les processus et les planifications de recharge, une étude d'optimisation d'affectation de VEs aux stations de recharge a été effectuée. Pour ce faire, le problème a été formalisé par un programme linéaire avec un objectif à atteindre et des contraintes, liées aux caractéristiques des VEs, des stations de recharge et des conditions de circulation, à satisfaire. Cette approche a permis d'affecter, de manière adéquate et optimale, les VEs aux stations de recharge. / The strong dependence on oil and ecological and environmental constraints force many car manufacturers to develop new research programs for the promotion of electric vehicles (EVs) and associated infrastructures. The embedded batteries into the EVs can be charged by the electrical network or by another source of renewable energy. In this context, the work presented in this thesis aims to study a system of EVs charging using solar energy through photovoltaic panels. To do so, a sizing study of the system has been proposed in order to evaluate the energy needs for an EV and determine the quantity of required energy for its propel. The key elements of the system have been sized: photovoltaic panels, storage battery (Lead-acid) and traction battery (Li-ion). From this sizing study and considering the EV characteristics, we determined the energy quantity required for itspropel. With the aim to study the behavior of each system component and analyze its adequacy with the charging process, a modeling study was conducted, and each element is represented by a mathematical model. The performed analysis and comparison of obtained results (simulation results and experimental results) allowed us to validate the developed models. In addition, this modeling study, allowed the validation of the choice of all components of charging system. In fact, the problem was formalized by a linear program with the aim to assign each EV to an adequate charging station. The assignment takes into account various constraints and characteristics of EVs, as well as those of charging stations, traffic conditions, interest points of drivers, etc. The proposed approach allowed to assign adequately and optimally EVs to charging stations while satisfying all constraints.