The wide spread adoption of solar photovoltaic cells is impeded by a number of factors, the primary one of which is the cost. The technology behind the most used cells today is based on bulk single crystalline silicon wafers. These wafers subsequently undergo numerous processesto produce a finished module capableo f delivering usable direct current electricity. Even with all these processes, the single biggest contributor to production costs is the starting wafer - estimated to account for some 50% of manufacturing costs. Removing these costs by replacing the wafer is the leading topic in solar cell research today. Glass is the most convenient starting point for replacing silicon wafers - it is benign, both from an environmental and manufacturing viewpoint, and is considerably less expensive than silicon wafers for a given quantity. As an amorphous material, glass is well suited to acting as a substrate for amorphous silicon layers used in low cost cells. Amorphous silicon cells suffer from stability issues and can degrade in performance substantially over the operational lifetime of the solar cell. To overcomethese problems the amorphous silicon can be replaced with crystalline silicon material. Generally, the deposition of suitable crystalline material occurs at a temperature in excess of the softening point of glass. So however useful glass is as a substrate it is incompatible with simple, low temperature formation of crystalline silicon using most techniques. There are two outstanding issues relating to the manufacture of thin film silicon solar cells that have been researched for this thesis. One is the deposition of silicon layers at a growth rate high enough to allow for a reasonable throughput of material. The second is the production of material suited to the task i.e. structurally and electrically. In this thesis the direct deposition of high quality polycrystalline silicon( near-single orientation with suitable electrical characteristics) using electron cyclotron resonance plasma enhanced chemical vapour deposition(E CR PECVD) onto glass is demonstrated. A new visualisation of the magnetic field used in E R PECVD has given an insight into the optimisation of the deposition process using this technique. By adjusting the magnetic field appropriately, an increase in growth rate for deposition of polycrystalline silicon of 2- 25 times that reported in the literature was found. In addition to the characterisation of the deposited material, the process parameters have been fully investigated by analysing the process plasma characteristics using a Langmuir probe. An amorphous incubation layer 1 micron thick is seen when the polycrystalline material is deposited directly on glass, however this layer can be substantially reduced by depositing on a thin layer of silicon (on the glass) which has been crystallised by excimer laser irradiation. This indicatesa possible direction in combining these two approaches in future manufacturing processes for the growth of low-temperature polycrystalline silicon layers on glass to form photovoltaic devices.

This report studied innovation activity in four areas of the solar photovoltaic balance-of-system (BOS) technologies (inverters, mounting equipment, monitoring systems, and site assessment) in the Japanese market. Through patent searches with specific keywords, this study found that innovation activity in these four technology areas increased and decreased responding to both supply-side and demand-side policies. This report also empirically studied effects of demand-pull policies on innovation activity in the BOS technology areas. The regression analysis of the patent data found that the demand-side policies such as residential subsidy programs employed by the Japanese government were a major factor which influenced innovation activities in these technology areas in the Japanese market. Finally, the regression analysis also found that the termination of the residential subsidy program by the government in 2006 had a negative effect on the innovation activity of the four BOS technologies. / text

The design processes for solar photovoltaic (PV) systems is improved to achieve higher reliability and reduced levelised cost of energy (LCOE) throughout this thesis. The design processes currently used in the development of PV systems are reviewed. This review process included embedding the author in a project to deliver four rooftop PV systems which totalled a megawatt of installed generating capacity, which at the time represented very significant system sizes. The processes used in this are analysed to identify improvement potential. Shortcomings are identified in three main areas: safety assurance, design process integration and financial optimisation. Better design process integration is required because data is not readily exchanged between the industry standard software tools. There is also a lack of clarity about how to optimise design decisions with respect to factors such as shading and cable size. Financial optimisation is identified as a challenge because current software tools facilitate optimising for maximum output or minimum cost, but do not readily optimise for minimum levelised cost of energy which is the primary objective in striving for grid parity. To achieve improved design process integration and financial optimisation, a new modelling framework with the working title SolaSIM is conceived to accurately model the performance of solar photovoltaic systems. This framework is developed for grid connected systems operating in the UK climate, but it could readily be adapted for other climates with appropriate weather data. This software development was conducted using an overarching systems engineering approach from design and architecture through to verification and validation. Within this SolaSIM framework, the impact of shading on array and inverter efficiency is identified as a significant area of uncertainty. A novel method for the calculation of shaded irradiance on each cell of an array with high computational efficiency is presented. The shading sub-model is validated against outdoor measurements with a modelling accuracy within one percent. Final verification of the over-arching SolaSIM framework found that it satisfied the requirements which were identified and actioned. The author installed the new CREST outdoor measurement system version 4 (COMS4). COMS4 is a calibrated system which measures 26 PV devices simultaneously. Validation of SolaSIM models against COMS4 found the modelling error to be within the 4% accuracy target except two sub-systems which had electronic faults. The model is validated against PV systems and found to be within the specified limits.

To accommodate the crisis of global warming and fossil fuel shortage, the world starts to value continual development and application of all sorts of green energy. Among various renewable sources of energy, solar energy is distinct for its low pollution and renewability. Under the standard of zero harm to the environment and low-carbon emission, solar energy is deemed the new green energy to replace fossil fuel. Consequently, governments around the world, one after the other, invest in research and development, and make solar energy the highest potential energy industry in industrial development by means of governmental policy and subsidy. This research focuses on the development and current status of solar cell industry in Greater China and other developed countries, and sets out to identify the co-opetition of current solar energy development of solar cell industry in Greater China in light of analysis based on Michael Porter diamond model and industry life cycle with the secondary data gathered in relation to solar photovoltaic industry chain. This research discovers that, in recent years, the solar cell industry has phenomenon of hasty expansion, intensive competition, petty profit at the middle range of industry chain, and manufacture switching to regions with low production cost. It is suggested in this research that to combine strength of industrially connected parties, make the economic industry more open, create a win-win situation, and embrace the upcoming of low-carbon economy, a series of actions may be considered. They are (1) strategic alliance of vertical integration and division by profession, (2) enhance industrial technology communication and cooperation to solve problem of technology and manufacturer, (3) elaborate complementary strengths and optimize integration of industry chain, (4) combine with comprehensive policy and actuate the solar photovoltaic market of Greater China.

Human-induced climate change, with its potentially catastrophic impacts on weather patterns, water resources, ecosystems, and agricultural production, is the toughest global problem of modern times. Impeding catastrophic climate change necessitates the widespread deployment of renewable energy technologies for reducing the emissions of heat-trapping gases, especially carbon di-oxide (CO₂). However, the deployment of renewable energy technologies is plagued by various market failures, such as environmental externalities from conventional energy sources, learning-by-doing, innovation spillover effects, and peer effects. In efforts to begin to address these market failures, several governments at all levels—city, state, regional, and national—have instituted various subsidies for promoting the adoption of renewable energy technologies. Public resources are limited and have competing uses. So, it is important to ask: how cost-effective are renewable energy subsidies? Are the subsidies even reaching the intended subjects—the potential adopters of renewable energy technologies? In this empirically-driven dissertation, I analyze these important policy design and evaluation questions with a focus on the solar subsidy programs in California. All programs to incentivize the adoption of renewable energy technologies run into the same key question: what is the optimal (maximum capacity inducing) rebate schedule in the face of volatile product prices and the need for policy certainty? Answering this question requires careful attention to both supply-side (learning-by-doing) and demand-side (peer effects) market dynamics. I use dynamic programming to analyze the effectiveness of the largest state-level solar photovoltaic (PV) subsidy program in the U.S. – the California Solar Initiative (CSI) – in maximizing the cumulative PV installation in California under a budget constraint. I find that previous studies overestimated learning-by-doing in the solar industry. Consistent with other studies, I also find that peer effects are a significant demand driver in the California solar market. The main implication of this empirical finding in the dynamic optimization context is that it forces the optimal solution towards higher subsidies in earlier years of the program, and, hence, leads to a lower program duration (for the same budget). In particular, I find that the optimal rebate schedule would start not at $2.5/W as it actually did in CSI, but instead at $4.2/W; the effective policy period would be only three years instead of the realized period of six years. This optimal (i.e., most cost effective) solution results in total PV adoption of 32.2 MW (8.1%) higher than that installed under CSI, using the same budget. Furthermore, I find that the optimal rebate schedule starts to look like the actual CSI in a ‘policy certainty’ scenario where the variation of periodic subsidy-level changes is constrained. Finally, introduction of stochastic learning-by-doing as a way to better capture the dynamic nature of learning in markets for new products does not yield significantly different results compared to the deterministic case. Another, still-unanswered, redistribution question related to the CSI program is: to what degree have the direct PV incentives in California been passed through from installers to consumers? I address this question by carefully examining the residential PV market in California by applying multiple methods. Specifically, I apply a structural-modeling approach, a reduced-form regression analysis, and regression discontinuity designs to estimate the incentive pass-through rate in California’s solar program. The results consistently suggest a high average pass-through rate of direct incentives of nearly 100%, though with regional differences among California counties and utilities. While these results could have multiple explanations, they suggest a relatively competitive market and a smoothly operating subsidy program. Combining evidence from the optimal subsidy policy design and the incentive pass-through analysis, this dissertation lends credibility to the cost-effectiveness of CSI given CSI’s design goal of providing policy certainty and also finds a near-perfect incidence in CSI. Long-term credible commitment as reflected through CSI’s capacity-triggered step changes in rebates along with policy and data transparency are important factors for CSI’s smooth and cost-effective functioning. Though CSI has now wound down because final solar capacity targets have been reached, the historical performance of CSI is relevant not only as an ex-post analysis in California, but potentially has broader policy implications for other solar incentive programs both nationally and internationally. / text

Due to their unique properties, nanoparticles have been a focus of significant research interest for use in various opto-electronic applications, particularly in the field of solar energy generation. In order to realize a nanoparticle-based solar cell, it is important to be able to create thin films of organised nanoparticles and to be able to control their surface properties. In this work the use of a novel synthesis technique involving reaction at the interface between two immiscible liquids to synthesise thin films of lead sulfide nanoparticles on the order of ~10 nm in diameter is reported. The use of the liquid-liquid interface allows the synthesis of particles without the use of stabilising ligands, with sizes and morphologies determined by the conditions present at the interface. Variations in the precursor used, solvent height, and precursor concentration were explored. Films synthesised at various solvent heights displayed a decrease in particle size with increasing solvent height. This trend was seen to vary depending on the lead-containing precursor used. Changes in the precursor concentration resulted in changes in the morphology of the resulting particles as observed with transmission electron microscopy (TEM). Preferential growth along certain planes was observed for particles synthesised with the highest lead precursor concentration. Experiments with precursors with differing organic chain length displayed an increase in particle size with increasing chain length, as well as an increase in preferential growth observed by X-ray diffraction (XRD). Surface ageing was investigated using X-ray photoelectron spectroscopy (XPS) techniques, which showed that all samples followed a similar oxidation mechanism. Oxidised lead species, attributed to hydrated lead oxide, were determined to be the initial oxidation product, formed within a week of exposure to air. Sulfoxy species were observed to form over a greater length of time, with sulfate being determined to be the final oxidation product. An oxidation mechanism is proposed based on XPS analysis of films exposed to air for up to nine months.

No description available.

In South Africa, there is an increasing interest in installing rooftop mounted solar photovoltaic systems. However, financing the photovoltaic systems causes most interest to be abandoned, largely due to the cost required to replace a building's asbestos roof. An alternative solution to replacing an asbestos roof is to install a ground-mounted photovoltaic system, which is more costly compared to a rooftop mounted system. This study aims to determine if a ground-mounted or a rooftop mounted solar photovoltaic system is the most financially feasible solar photovoltaic configuration. In this study three photovoltaic systems were analysed, all of which are installed in Atlantis, Western Cape (WC). Since all three systems are in the same area, they are all exposed to the same metrological conditions, allowing for identical energy generation potential. Two of the photovoltaic systems are ground-mounted systems located respectfully at the South African Renewable Energy Incubator (SAREBI) and at Stripform Packaging. The third system is a rooftop mounted system located at SA Tyre Recyclers. The photovoltaic system at SAREBI is a 9.75 kWp system consisting of 30 Canadian Solar CS6U-325P modules, one Schneider Electric 20 kW inverter, a tilt angle of 15° and an azimuth angle of -19°. The photovoltaic system at SA Tyre Recyclers is a 231 kWp system consisting of 700 JA Solar JAP72S-01-330-SC modules, 7 SolarEdge 27.6 kW inverters, a tilt angle of 13° and an azimuth angle of 22°. The photovoltaic system at Stripform Packaging is a 20.1 kWp system consisting of 60 Canadian Solar CS6U-335P modules, one SMA 20 kW inverter, a tilt angle of 15° and an azimuth angle of 46°. To achieve the aim of this study, the performance of each of the solar photovoltaic systems was examined, by comparing their annual specific yield. After which the technical aspects and differences of each of the photovoltaic systems were explored, to illustrate how each of the systems differ technically and how each system can be improved. Finally, the comparative cost of each of the solar photovoltaic systems was examined by analysing the levelized cost of energy (LCOE) and the payback period for each of the photovoltaic systems. The results demonstrated that from an annual specific yield perspective, the ground-mounted configuration was the best performing, whilst from a financial perspective, the rooftop mounted configuration had the lowest levelized cost of energy (LCOE) and payback period. However, installing a ground-mounted system is more financially feasible than replacing an asbestos roof and then installing a rooftop mounted system. In conclusion, by fully understanding the performance, payback period and levelized cost of energy, a clear understanding of potential risk can be determined, thus making the installation of photovoltaic systems more appealing for financiers. It is recommended that this study be repeated in a manner in which each of the photovoltaic system configurations are constructed consisting of all the same photovoltaic components, measuring equipment, tilt and azimuth angles. All of which would result in two identical photovoltaic systems where one is installed on a rooftop and the other installed on the ground. Once the two photovoltaic system configurations are equal in all aspects, an accurate comparison to determine which configuration is the most optimal performer and which is the most financially viable will be possible.

Este trabalho propõe caracterizar a complementaridade espacial-temporal entre energia eólica e solar fotovoltaica entre regiões do Brasil e estudar, no âmbito da comercialização de energia elétrica no Setor Elétrico Brasileiro - SEB, se um portfólio formado por estas fontes trazem vantagens econômicas relevantes para o investidor. Para atender a estes objetivos, foram estudados métodos para tratamento dos dados como a correção da irradiância solar, cálculo da energia gerada pelas fontes estudadas, o ambiente de contratação de energia elétrica no Brasil, métodos de otimização e modelos de análise de risco para contratação de energia no mercado livre de energia. A metodologia proposta para responder as questões colocadas foi aplicada em um estudo de caso envolvendo três regiões brasileiras em um horizonte de dez anos. Concluiu-se que existe a complementaridade energética entre as fontes nas diferentes regiões estudadas e em diferentes períodos de tempo. Confirmou-se que tecnicamente pode-se reduzir a oscilação na geração de energia analisando as fontes de forma complementar, porém, o custo de instalação da fonte fotovoltaica ainda é muito alto, inviabilizando até o momento investimentos em larga escala e de forma complementar a fonte eólica. Também verificou-se, dentro dos locais avaliados, que somente um dos três locais apresentou benefício econômico-financeiro com a formação de portfólio das fontes eólica e solar atuando no mercado de venda de energia e atendendo os critérios de risco limite estabelecidos quando avaliadas segundo a ótica da maximização da receita no mercado livre. / This thesis proposes to characterize the spatial-temporal complementarity between wind and solar photovoltaic energy between regions of Brazil and study, in the marketing of electricity in the Brazilian Electrical Sector - SEB, a portfolio formed by these sources bring significant economic benefits to the investor. To meet these goals, methods for data processing were studied as correction of solar irradiance calculation of the energy generated by the sources studied, the environment of contracting electricity in Brazil, optimization methods and models for risk analysis for contracting energy in the free energy market. The proposed methodology to answer the questions was applied in a case study involving three Brazilian regions with a horizon of ten years time series. It was concluded that there is complementarity between energy sources in the different regions studied and in different time periods. It was confirmed that technically can reduce the fluctuation in power generation by analyzing the complement of sources, however, the installation cost of photovoltaic power is still too high, preventing yet large-scale investments and complementary way the source wind. Also it was found within the sites evaluated, only one of the three sites presented economic and financial benefit by the portfolio of wind and solar sources acting in the sale of energy market and considering the risk criteria limit established when evaluated according to perspective of maximizing revenue in the free energy market.

O objetivo desse estudo é analisar e sistematizar os elementos necessários à modelagem da energia primária solar para geração fotovoltaica em escala. Metodologicamente, investigam-se os assuntos inerentes à solarimetria e a caracterização da radiação solar, desde a formação das equações que definem a incidência da radiação no topo da atmosfera, o desenvolvimento tecnológico de radiômetros, até as normas e critérios de classificação desses equipamentos. Também são elementos metodológicos a caracterização do irradiância solar, incluindo algoritmos de tratamento de dados de irradiância, os processos de estimativa de irradiação para a agricultura e análises probabilísticas de índices de transmitância atmosférica. Busca-se a aplicação das etapas de caracterização e a análise do recurso, definidas neste estudo, por meio da utilização dos dados fornecidos por duas estações solarimétricas: ESUPP e ESPEL. Como resultados são definidos a média diária parcial anual de disponibilidade do recurso para uma região no interior do estado de São Paulo (localização da ESUPP) em 5,29 kWh/m² e a média diária anual de disponibilidade do recurso para a região metropolitana da cidade de São Paulo (localização da ESPEL) em 4,41 kWh/m², além disso verifica-se que a relação entre as componentes global horizontal, difusa horizontal e direta vertical varia para os dados das duas estações solarimétricas, de modo que, parte significativa dos dados da ESPEL apresenta medições de irradiância global horizontal (IGH) entre 12% e 13% superiores à respectiva componente difusa horizontal (IDH) somada a parcela vertical da respectiva componente direta normal (IDNcos?z), enquanto que, essa mesma relação para os dados da ESUPP atendem à relação IGH=IDH+IDNcos?z dentro do intervalo aceitável de mais ou menos 10%. Verifica-se também caráter trimodal das curvas de densidade de probabilidade do índice de transmitância da irradiância global para os dados da ESPEL, enquanto os dados da ESUPP refletem em curva de caráter bimodal. Assim é possível constatar a necessidade de definição de um modelo universal de previsibilidade do recurso e verifica-se que os insumos mais relevantes para o modelo podem variar de região para região dada a caracterização geográfica e de microclima. Conclui-se, portanto, a indiscutível necessidade de dados radiométricos confiáveis medidos em solo para avanços científicos, tecnológicos e comerciais do aproveitamento do recurso solar como fonte energética diante do atual contexto da busca por fontes alternativas de energia limpa e evidencia-se o grande caminho a ser percorrido para a consolidação de uma rede confiável, monitorada e amplificada de medições solarimétricas no Brasil e no mundo. / The purpose of this study is to analyze and to systematize the elements required for modeling primary solar energy for photovoltaic generation in large scale. Solarimetric subjects and subjects related to solar irradiance flux characterization, from the formation of the equations that define the incidence of radiation at the top of the atmosphere, the technologic development of radiometers and the rules and criteria for the classification of these measurement instruments, are methodologically investigated. The characterization of the irradiance flux, including irradiance data treatment algorithms, the irradiance estimate processes for agriculture, and the probability analyses of atmosphere transmittance indexes are also methodological elements. The steps of characterization and resource analysis defined in this study are applied, using data provided for two solarimetric stations: ESUPP and ESPEL. Results showed that the partial annual daily average for resource availability in the countryside of São Paulo State (ESUPP location), is 5.9 kWh/m², and the annual daily average for resource availability in the metropolitan area of São Paulo City (ESPEL location) is 4.41 kWh/m². Moreover, it was observed that the relation between the global horizontal, diffuse horizontal and direct vertical components varies between both solarimetric stations, such that a significant part of the ESPEL data shows global horizontal irradiance (GHI) between 12% and 13% above the respective diffuse horizontal irradiance (DHI) plus the vertical portion of the respective direct normal component (DNIcos?z), while the same relation for the ESUPP data attend the GHI=DHI+DNIcos?z relation within the acceptable range of 10%, give or take. ESPEL data presented trimodal characteristics for the probability density curves of the transmittance index for global irradiation, while ESUPP data reflect on the same curve, with bimodal characteristics. Therefore, it is possible to verify the need of the determination of a universal predictability model of the resource and it is possible to affirm that the more relevant inputs to the model can vary from region to region, depending on the geographic character and microclimate. In conclusion, there is an unquestionable need for reliable radiometric data, measured in ground, for scientific, technologic and commercial advances to improve the use of solar resource as energy source, considering the current scenario, which demands alternative sources for clean energy. It is also evident that there is still a long path to be tracked in order to consolidate a reliable, monitored and amplified network for solarimetric measurements in Brazil and in the world.