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Climate change is no longer a problem of the future. Climate change is global, rapid, and intensifying. A reality. The latest Intergovernmental Panel on Climate Change (IPCC) report highlights the Anthropocene is behind the unprecedent rising temperatures, leading to extreme weather events such as heatwaves, droughts, heavy precipitation, or tropical cyclones. Climate action must be taken. The energy transition plays a fundamental role when considering the wellbeing of the planet. However, renewable energy finance has always been a challenge. To date, the energy transition has been regrettably underfunded. In 2018, the global energy system was below 50 % of the investment required to keep global warming below 1.5 °C and avert the worst consequences of the climate crisis[4]. This staggering statistic clearly shows that financial investment needs to either be redirected to the energy transition, or new financing channels must be open. Seeds Renewables, a California-based startup, has come up with a solution which has the potential to cover a portion of the energy financing deficit by enabling people to invest in renewable energy projects from as little as their spare change. Before allowing their users to invest, Seeds carries out the due diligence of the projects to determine the feasibility of the installation. It is identified that there is a current lack of concise and public literature regarding the process required to determine the technical feasibility and economic profitability of projects. This thesis serves as a guide for lenders, such as Seeds Renewables, who aim to conduct techno-economic assessments on solar photovoltaic installations. This core objectiveis complemented by qualitative checklists for project development and legal due diligence to provide a comprehensive overview of the factors which surround the techno-economic analysis of solar arrays. Furthermore, the optimal software available in the market to carry out an analysis of solarphotovoltaic installation is identified. The thesis covers the background research conducted on solar photovoltaic systems, acompilation of project due diligence best practices, insights on renewable energy project finance anda literature review on photovoltaic analysis software tools which leads to the selection of two softwares. PVsol and PVsyst are compared by means of a Multi-Criteria Analysis. A case study is conducted on a 63.3 kW solar photovoltaic array installed in 2016 to test the selected softwares. The array is located on the roof of Rinaldi Tile in Pajaro, California, United States of America. The array is replicated using PVsol and PVsyst. Consequently, the simulation predictions are compared to the real production data extracted from the system’s inverter. The performance ratio from the real data, PVsol and PVsyst are 82.4 %, 85.9 %, 80.51 % respectively. The real quantity of power produced over a 5-year period of study is average of 82.24 MWh whilethe simulations by PVsol and PVsyst predict 93.49 MWh and 81.30 MWh respectively. The discrepancy between the real data and software results is due to limitations of both tools. After evaluating the accuracy of the solar PV simulation tools, the Multi-Criteria Analysis rates PVsyst as the more desirable tool. Using this study, engineers or investors will have a clear framework to follow when carrying out the project due diligence on a solar photovoltaic installation and a rating of the available softwaresto assess the viability of the solar arrays. / Klimatförändringarna är inte längre ett framtidsproblem. Klimatförändringarna är globala, snabba och intensifierande. En verklighet. Den senaste Intergovernmental Panel on Climate Change (IPCC) rapporten visar att Antropocen ligger bakom de aldrig tidigare skådade temperaturerna, vilket leder till extrema väderhändelser som värmeböljor, torka, kraftig nederbörd eller tropiska cykloner. Klimatåtgärder måste vidtas. Energiomställningen spelar en grundläggande roll när man överväger planetens välbefinnande. Finansiering av förnybar energi har dock alltid varit en utmaning. Hittills har energiomställningen tyvärr varit underfinansierad. År 2018 låg det globala energisystemet under 50% av investeringarna som krävs för att hålla den globala uppvärmningen under 1,5 ° C och avvärja de värstakonsekvenserna av klimatkrisen [4]. Denna häpnadsväckande statistik visar tydligt att finansiella investeringar antingen måste omdirigeras till energiomställningen eller att nya finansieringskanaler måste vara öppna. Seeds Renewables, en Kalifornienbaserad startup, har kommit fram till en lösning som har potential att täcka en del av energifinansieringsunderskottet genom att göra det möjligt för människor att investera i förnybara energiprojekt från så lite som deras växel. Innan de tillåter sina användare att investera, utför Seeds projektets due diligence -analys för att avgöra genomförbarheten av installationen. Det identifieras att det för närvarande saknas kortfattad och offentlig litteratur om processen som krävs för att bestämma projektens tekniska genomförbarhet och ekonomiska lönsamhet. Denna avhandling fungerar som en vägledning förlångivare, till exempel Seeds Renewables, som syftar till att göra tekno-ekonomiska bedömningar avsolcellsanläggningar. Detta kärnmål kompletteras med kvalitativa checklistor för projektutvecklingoch juridisk due diligence för att ge en övergripande överblick över de faktorer som omger den tekno-ekonomiska analysen av solsystem. Dessutom identifieras den optimala programvara som finns tillgänglig på marknaden för att utföra en analys av solcellsinstallation. Avhandlingen omfattar bakgrundsforskning på solcellssystem, en sammanställning av bästa praxis för aktsamhet, insikter om projektfinansiering för förnybar energi och en litteraturgenomgång om programvara för fotovoltaiska analyser som leder till val av två programvaror. PVsol och PVsyst jämförs med hjälp av en multikriterieanalys. En fallstudie genomförs på en solcellsanläggning på 63,3 kW installerad 2016 för att testa de utvalda programvarorna. Arrayen ligger på taket av Rinaldi Tile i Pajaro, Kalifornien, USA. Arrayen replikeras med PVsol och PVsyst. Följaktligen jämförs simuleringsprognoserna med de verkliga produktionsdata som extraherats från systemets inverter. Prestandakvoten från de verkliga uppgifterna, PVsol och PVsyst är 82.4 %, 85,9% respektive 80,51%. Den verkliga mängden kraft som produceras under en 5-års studieperiod är i genomsnitt 82,24 MWh medan simuleringarna av PVsol och PVsyst förutsäger 93,49 MWh respektive 81,30 MWh. Skillnaden mellan de verkliga data- och programvareresultaten beror på begränsningar för båda verktygen. Efter att ha utvärderat noggrannheten i solcells-PV-simuleringsverktygen med multikriterieanalysen bedöms Multi-Criteria Analysis PVsyst som det mer önskvärda verktyget. Med hjälp av denna studie kommer ingenjörer eller investerare att ha en tydlig ram att följa när projektet genomförs due diligence på en solcellsanläggning och en bedömning av de tillgängliga programvarorna för att bedöma matrisernas livskraft.

The study started with the requirement that a photovoltaic (PV) power source should be integrated with other supplementary power sources whether it operates in a stand-alone or grid-connected mode. First, fuel cells for a backup of varying PV power were compared in detail with batteries and were found to have more operational benefits. Next, maximizing performance of a grid-connected PV-fuel cell hybrid system by use of a two-loop controller was discussed. One loop is a neural network controller for maximum power point tracking, which extracts maximum available solar power from PV arrays under varying conditions of insolation, temperature, and system load. A real/reactive power controller (RRPC) is the other loop. The RRPC meets the system's requirement for real and reactive powers by controlling incoming fuel to fuel cell stacks as well as switching control signals to a power conditioning subsystem. The RRPC is able to achieve more versatile control of real/reactive powers than the conventional power sources since the hybrid power plant does not contain any rotating mass. Results of time-domain simulations prove not only effectiveness of the proposed computer models of the two-loop controller, but also their applicability for use in transient stability analysis of the hybrid power plant. Finally, environmental evaluation of the proposed hybrid plant was made in terms of plant's land requirement and lifetime CO2 emissions, and then compared with that of the conventional fossil-fuel power generating forms. / Ph. D.

<p dir="ltr">The demand for sustainable and renewable energy sources has prompted significant research and development efforts in the field of biomass gasification. Biomass gasification technology holds significant promise for sustainable energy production, offering a renewable alternative to fossil fuels while mitigating environmental impact. This thesis presents a detailed study on the design, development, and implementation of a Plug-Flow Reactor Biomass Gasifier integrated with an Automated Auger Jam Detection System and a Blower Algorithm to maintain constant reactor pressure by varying blower speed with respect to changes in reactor pressure. The system is based on indirectly- heated pyrolytic gasification technology and is developed using Simulink™.</p><p dir="ltr">The proposed gasification system use the principles of pyrolysis and gasification to convert biomass feedstock into syngas efficiently. An innovative plug-flow reactor configuration ensures uniform heat distribution and residence time, optimizing gasification performance and product quality. Additionally, the system incorporates an automated auger jam detection system, which utilizes sensor data to detect and mitigate auger jams in real-time, thereby enhancing operational reliability and efficiency. By monitoring these parameters, the system detects deviations from normal operating conditions indicative of auger jams and initiates corrective actions automatically. The detection algorithm is trained using test cases and validated through detailed testing to ensure accurate and reliable performance.</p><p dir="ltr">The MATLAB™-based implementation offers flexibility, scalability, and ease of integration with existing gasifier control systems. The graphical user interface (GUI) provides operators with real-time monitoring and visualization of system status, auger performance, and detected jam events. Additionally, the system generates alerts and notifications to inform operators of detected jams, enabling timely intervention and preventive maintenance. </p><p dir="ltr">To maintain consistent gasification conditions, a blower algorithm is developed to regulate airflow and maintain constant reactor pressure within the gasifier. The blower algorithm dynamically adjusts blower speed based on feedback from differential pressure sensors, ensuring optimal gasification performance under varying operating conditions. The integration of the blower algorithm into the gasification system contributes to stable syngas production and improved process control. The development of the Plug-Flow Reactor Biomass Gasifier, Automated Auger Jam Detection System, and Blower Algorithm is accompanied by rigorous simulation studies and experimental validation.</p><p dir="ltr">Overall, this thesis contributes to the advancement of biomass gasification technology by presenting a detailed study on a plug flow reactor biomass gasifier with indirectly- heated pyrolytic gasification technology with an Automated Auger Jam Detection System and Blower Algorithm. The findings offer valuable insights for researchers, engineers, policymakers, and industry stakeholders supporting the transition towards cleaner and more renewable energy systems.</p>

Organic and hybrid organic-inorganic photovoltaic (PV) devices have the potential to provide low-cost, large scale renewable energy. Despite the tremendous progress that has been made in this field, device efficiencies remain low. This low efficiency can be partly attributed to the low open-circuit voltages (Voc) generated by organic and hybrid organic-inorganic PV devices. The Voc is critically determined by the energy-level alignment at the interface between the materials forming the device. In this thesis we use first-principles methods to explore the energy-level alignment at the interfaces between the conjugated polymer poly(3-hexylthiophene) (P3HT) and three electron acceptors, zinc oxide (ZnO), gallium arsenide (GaAs) and graphene. We find that Voc reported in the literature for ZnO/P3HT devices is significantly lower than the theoretical maximum and that the interfacial electrostatic dipole plays an important role in the physics underlying the charge transfer at the heterojunction. We note significant charge transfer from the polymer to the semiconductor at GaAs/P3HT interfaces, and use this result to help interpret experimental data. Our findings support the conclusion that charge transferred from P3HT to GaAs nanowires can passivate the surface defect states of the latter and, as a result, account for the observed decrease in photoluminescence lifetimes. Finally, we explore the energy-level alignment at the graphene/P3HT interface and find that Voc reported for experimental devices is in line with the theoretical maximum. The effect of functionalised graphene is also examined, leading to the suggestion that functionalisation might have important consequences for device optimisation.

No description available.

Organic solar cells offer the possibility for lightweight, flexible, and inexpensive photovoltaic devices. This thesis studies the physics of a wide range of materials designed for use in organic solar cells. The materials investigated include conjugated polymers, conjugated dendrimers, and inorganic nanocrystals. The materials studied in this thesis fall into five categories: conjugated polymers blended with a buckminsterfullerene derivative PCBM, nanocrystals synthesised in a conjugated polymer matrix, conjugated polymers designed for intramolecular charge separation, conjugated dendrimers blended with PCBM, and nanocrystals synthesised in a matrix of conjugated small molecules or dendrimers. Conjugated polymers blended with PCBM have been extensively studied for photovoltaic applications, and hence form an ideal test bed for new experiments. In this thesis this blend was used to achieve the first pulsed electrically detected magnetic resonance experiments on organic solar cells. Nanocrystals are attractive for photovoltaics because it is possible to tune their band gap across the solar spectrum. In this thesis a one-pot synthesis is used to grow PbS and CdS nanocrystals in conjugated polymers, soluble small molecules, and dendrimers, and characterisation is performed on these composites. Previous work on dendrimer: nanocrystal composites has been limited to non-conjugated molecules, and the synthesis developed in this thesis extends this work to a conjugated oligomer and a conjugated dendrimer. This synthesis can potentially be extended to a variety of conjugated soluble small molecule: nanocrystal and dendrimer: nanocrystal systems. Conjugated dendrimers have been successfully employed in organic light emitting diodes, and in this thesis they are applied to organic solar cells. Materials based on fluorene and cyanine dye cores show excellent absorption tunability across the solar spectrum. A set of electronically asymetric polymers designed for intramolecular charge separation were investigated. Quenching of the luminescence was observed, and light induced electron paramagnetic resonance measurements revealed that photoexcitation led to approximately equal numbers of positive polarons and nitro centred radical anions. This indicates that charge separation is occurring in these molecules.