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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Hydrogen and fuel cells: an efficient and clean energy alternative / Hidrógeno y pilas de combustible: una alternativa energética limpia y eficiente

Laguna Bercero, Miguel A. 25 September 2017 (has links)
El avance tecnológico más importante de las próximas décadas pasa por el uso del hidrógeno como combustible, sustituyendo el consumo masivo de los combustibles fósiles. De esta manera, utilizando tecnologías basadas en pilas de combustible, conseguiremos sistemas energéticos más eficientes que los actuales y, además respetuosos, con el medio ambiente. / The most important technological development in the coming decades will be the use of hydrogen as an alternative to the widely used fossil fuels. By the use of fuel cell based technologies, it will be feasible to produce energy systems that will be more efficient than the current ones and that will also be environmentally friendly.
22

O uso de fontes limpas de energia na indústria paulista: um estudo envolvendo a técnica do incidente crítico e a análise conjunta / The use of clean energy resources in the São Paulo state industry: a study involving the critical incident technique and conjoint analysis

Flávia de Castro Camioto 10 June 2010 (has links)
O presente trabalho tem o objetivo de identificar fatores intervenientes na adoção de energias limpas nos principais setores industriais do Estado de São Paulo. Para tanto, apresenta a fundamentação teórica sobre os diversos temas pertinentes a pesquisa, tais como: o atual cenário energético brasileiro e o desenvolvimento sustentável, bem como o estudo dos métodos aplicados. A análise dos dados realizada teve caráter qualitativo e quantitativo, por meio, respectivamente, da Técnica do Incidente Crítico e da Análise Conjunta. A aplicação da Técnica do Incidente Crítico forneceu os atributos que as empresas consideram importantes no processo de escolha. Já a Análise Conjunta, técnica estatística multivariada de análise de dados, foi utilizada para determinar a utilidade e importância relativa dos atributos relevantes na escolha das empresas. Com os resultados da pesquisa acredita-se que as empresas usuárias e não usuárias de energias limpas poderão ter conhecimentos sobre a opinião de seus pares com relação às vantagens e desvantagens do uso destes energéticos nos processos produtivos, assim como ao governo estabelecer estratégias adequadas para orientar e estimular a adoção de energias que promovem baixo impacto ao meio ambiente. / The scope of the present work is to identify intervening factors in the adoption of clean energy resources in the main industrial sectors of the São Paulo state. In order to perform such evaluation, a theoretical reasoning on the various relevant issues related to the research shall be displayed, such as: the current brazilian energy context and sustainable development, as well as the study of applied methods. The data analysis was realized guided on a qualitative and quantitative basis, by means, respectively, of the Critical Incident Technique and the Conjoint Analysis. The application of the Critical Incident Technique has imputed capabilities that companies regard as pivotal in the selection process. The Conjoint Analysis, on its hand, multivariate statistics technique on data analysis, was used in order to determine the utility and relative importance of the capabilities relevant to the companies\' selection. Based on the results inferred from the research it may be conjectured that companies that adopt and do not adopt clean energy resources may acquire acknowledge about the opinion of its couples in what it concerns the advantages and disadvantages of the use of these energetic in these productive processes, as well the government may set to establish adequate strategies in order to instruct and encourage the adoption of energy resources that promote a lesser impact to the environment.
23

Barriers and opportunities for implementation of Clean Development Mechanism in South Africa: a case study of Gauteng Municipalities

Ntuli, Princess Ntombifuthi 05 November 2012 (has links)
M.Phil. / Clean Development Mechanism (CDM) can be defined as one of the project-based mechanisms established under the Kyoto protocol mechanism as a supplementary measure to assist Annex 1 parties meet their emission reduction targets through investing in project activities that reduce Greenhouse Gas (GHG) emissions and contribute to sustainable development in Non–Annex 1 countries. These projects reduce GHG emissions and generate credits called Certified Emission Reductions (CERs) that the Annex 1 party can use to meet their emission reduction obligations under the Kyoto Protocol [Curnow & Hodes, 2009]. While countries such as China and India have benefited remarkably from the CDM, African countries (including South Africa (SA)) have failed to maximise the financial benefits offered by this mechanism. Even though South Africa is leading, in terms of the number of registered CDM projects in Africa, it is still lagging far behind other developing regions in this regard. The South African leaders in CDM project development are in the private sector. This research aims to identify the constraints that inhibit large scale implementation of CDM projects by Gauteng Municipalities and to investigate the reasons why South African municipalities are lagging behind the private sector in CDM project development, and identify opportunities for further development of CDM projects. This identification was achieved by compiling a list of known barriers (then investigating these barriers together with a number of other factors that may impact negatively on the CDM market in South Africa) The study was conducted using qualitative research techniques, which utilises methods such as participant observation, in-depth interviews and/or focus groups. Three different groups of respondents were identified: (i) the European CER buyers; (ii) the project developers/ CDM consultants in South Africa; and (iii) the Gauteng municipal officials responsible for CDM project development. A separate questionnaire was compiled for each of the three target groups, with purpose of drawing conclusions about the prevailing status of the South African CDM market from the perspectives of these three different groups. Three previous studies have been conducted to investigate the barriers of implementing CDM in South Africa, examining the problem from various perspectives. Little et al. [2007] conducted a study that focused on the inhibiting and facilitating factors affecting the implementation of CDM by South African industries. Wilson [2007] focused on the barriers against and drivers for the implementation of CDM within the Nelson Mandela Bay Municipality - this study drew conclusions about CDM implementation in municipalities based on the experiences of this single municipality. Winkler and van Es [2007] dealt with the opportunities and constraints of the CDM implementation in energy efficiency projects throughout South Africa.
24

Clean Lighting Leads to Improved Health in Rural Africa: Field Study and Design of a Dirt-Powered Generator

Aiden, Aviva Presser 01 May 2015 (has links)
Two billion people world-wide use kerosene-burning lamps for household lighting. These lamps produce large quantities of soot. In Chapter 2, I describe our field study examining 230 people in rural Uganda. I show that kerosene lamps are a major source of smoke exposure in the developing world, and that replacing such lamps with solar-powered lights reduces indoor soot levels 17-fold, leading to significant improvements in health within months. This finding is particularly notable because respiratory disease is the #1 cause of death in children under 5 worldwide. Because solar cells are a challenge to manufacture in the developing world, I next examined the potential of harvesting electrons from soil-based microbes as a source of clean energy. Such devices are known as microbial fuel cells (MFCs); because soil is available everywhere, MFCs can, in principle, be locally constructed all over the world. In Chapter 3, I describe our exploration of the biology of MFCs, using high-throughput DNA sequencing to demonstrate a role for genus Pseudomonas in energy production. I also examine numerous agricultural products available throughout the developing world to determine whether any could serve as a suitable ‘feed’ for MFC soil. I find that dried animal blood increases MFC energy production 10-fold. In Chapter 4, I describe our design of a modular, stackable MFC, demonstrate that it can be easily constructed in rural Africa, and use it to power lights and to charge a cell phone battery.
25

The development of a green energy sector model for the Southern African Development Community (SADC)

Ramagoma, Mbavhalelo Justice January 2016 (has links)
The Southern African Development Community (SADC) region, like most parts of the African continent, faces significant modern energy services access challenges. It is estimated that less than 45% of the SADC region’s populace have access to reliable modern energy forms and the situation is worse in rural areas where access is approximately 30%. Poor energy security is exacerbated by electricity power cuts and load shedding in almost all of the member states in the region. With the advent of battery storage, all forms of green energy have the potential to contribute to the shortfall in the supply of peaking power required to meet the daily (morning and evenings) and seasonal (winter) peaks when most power is required on the grid network. The region is endowed with vast green (renewables/low carbon or clean) energy resources. The purpose of this study is to expand the empirical body of research and knowledge on factors that contribute to widespread access success to green energy in the SADC region. Investments into green energy resources require an understanding of the unique characteristics of the energy sector in the region. In order to achieve this, a conceptual theoretical model was developed and tested empirically. Factors that influence green energy access success were identified through literature reviews and discussions with energy practitioners. All identified factors were then operationalised by carefully defining them in the context of the study. In order to test the proposed theoretical model and the hypothesised relationships, a structured questionnaire was developed and sent to energy practitioners from various sections of the energy sector in the region. STATISTICA 12 was employed to analyse relationships between variables and responses between identified groups. Pearson Product Moment Correlation (Pearson r) was employed to determine correlations between variables. Conclusions about hypotheses six (6) to fifteen (15) were made based on correlations between variables. T-tests were employed to make inferences about the views of various categories of respondents with regard to the twelve (12) identified variables. Multivariate analysis of variance (MANOVA) and Analysis of variance (ANOVA) examined associations between the dependent and independent variables with the identified categories of respondents and conclusions about hypotheses one (1) to five (5) and sixteen (16) were also made. The study finds that policy and the regulatory environment are still the main driving force behind energy access in the region. Power generation is managed by authorities’ power utility companies. Unbundling of power utilities supported by new energy business and operating models to accommodate mini and off grid power plants is found to be a key to green energy access in the region. The energy market is transforming in favour of independent power producers (IPPs) and consumers will significantly influence energy access decisions in the future. Green energy power storage to overcome intermittency will feature prominently in the success of green energy access in the region. Widespread access success to green energy will be attained when green energy access is reliable, affordable, efficient, and socially acceptable, meet the demand and reduces environmental pollution. The study recommends that strategic green energy planning must incorporate green energy infrastructure development, projects finance and human capacity development as priorities amongst SADC region’s member countries. Regional energy access enabling institutions must be strengthened; energy policies implemented with vigour and private sector participation enhanced in an integrated energy market.
26

Transition to clean household energy in low-income urban settlements of South Africa : safety, health and low carbon

Kimemia, David Kimani 02 July 2015 (has links)
D.Phil. (Environmental Management) / Clean, efficient, and low carbon energy services are crucial to the sustainable functioning of a household unit. Therefore, this study explores a vital query on the best pathway to achieve universal modern energy access in low-income South African households, based on information gathered from interviews in urban settlements. The thesis is based on published papers touching on thematic areas of household energy access – from baseline assessments to appraisal of modern energy programmes. A set of factors that are necessary for successful introduction and uptake of clean energy are identified for consideration by policy makers. Results indicate widespread use of paraffin and solid fuels in inefficient combustion technologies among low-income urban households even in the rich Johannesburg metropolis. In the absence of formal employment, some township residents use the basic fuels and conventional combustion technologies for productive purposes. Growth in the thermal-intensive informal businesses could be achieved faster through provision of efficient and reliable alternative energy technologies and better operational environment. This study has highlighted the undue risk borne by energy-poor households in the performance of the day-to-day energy tasks. The results show that household risk is positively correlated with the quality and quantity of energy used, with paraffin being the most risky fuel and the apparent risk being larger in non-electrified households. The affected communities have expressed a desire to adopt cleaner and safer forms of energy for residential and economic uses. It is incumbent upon the government and relevant role players to create enabling systems for acquisition of the preferred modern energy streams. An LPG intervention project in the City of Tshwane has demonstrated the inherent potential for modern energy to transform the socioeconomics and overall wellbeing of a family. The impact of such energy interventions could be improved through better-designed energy delivery models that cater for residential and productive needs, leading to sustainable communities. Education and income have been shown to be good precursors for modern energy uptake. Therefore, efforts towards sustainable energy for all should not only focus on indigent assistance and expansion of electrification, but also be intertwined with policies addressing skills need and better household incomes.
27

As the smoke clears: assessing the air pollution and health benefits of a nationwide transition to clean cooking fuels in Ecuador

Gould, Carlos Francisco January 2021 (has links)
Air pollution is the world’s greatest environmental health risk factor and reducing exposure remains an ongoing challenge around the world. Among the world’s poor, marginalized, and rural populations, household air pollution from the inefficient burning of biomass fuels like firewood, charcoal, dung, and agricultural residues for daily household energy needs is a leading cause of morbidity and mortality, especially for children under the age of five years. However, household air pollution exposure is a modifiable risk factor and clean-burning cooking fuels like gas and electricity promise substantial health benefits for the 2.8 billion people reliant on biomass fuels. But, clean fuels remain prohibitively expensive or inaccessible for those most reliant on biomass fuels. It is in this context that I examine Ecuador – where substantial cooking gas subsidies have facilitated a nationwide transition to household clean fuel use over four decades – as a long-term case study to understand the potential for widespread clean fuel uptake to reduce air pollution exposure and improve children’s health. Chapter 1 provides background information that contextualizes the work presented in this dissertation. In Chapter 2, I discuss the development of Ecuador’s clean fuel policies. Originally established as a part of broad social support reforms in the 1970s, direct-to-consumer subsidies that lowered the cost of liquefied petroleum gas (LPG) – a popular clean-burning cooking fuel used widely around the world – have driven a transition from 80% of households cooking primarily with firewood in the 1970s to now 90% relying primarily on LPG. However, widespread clean fuel use has come at a cost; each year, the Government of Ecuador spends approximately 1% of the national growth domestic product subsidizing LPG (300-700 million USD). To reduce this financial burden, the government has offered incentives to households to install and use induction electric stoves, which can be powered by the nation’s growing hydroelectric capacity, thereby reducing the cost of LPG subsidies and greenhouse gas emissions. To supplement national data, I administered household energy surveys in a northern province, finding that while all households regularly used LPG, 80% still used firewood for cooking. In these remote regions along the Colombian border, limited access to LPG cylinder refills remains a significant barrier to exclusive LPG use, even after decades of building a robust distribution system. In Chapter 3, I describe results from tailored household surveys – covering energy end uses, costs and access to fuels, and fuel use preferences – administered in 808 households across coastal and Andean Ecuador. Nearly all participants reported using LPG for more than a decade and having frequent, convenient access to cheap LPG cylinder refills. Nonetheless, half of rural households and one-fifth of peri-urban households relied on firewood for cooking and to meet specific household energy needs, like space heating or heating water for bathing. Induction stoves were rare and many induction stove owners reported zero use because the required equipment had never been installed by electricity companies, their stove had broken, or they feared high electricity costs. Here, I show that nationally-representative surveys reporting only “primary cooking fuel” use may underestimate solid fuel use as a secondary option, particularly in rural areas where LPG fuel availability issues play an important role in cooking fuel decision making. These findings additionally indicate that persistent biomass use may curtail the benefits from even the most aggressive clean fuel policies and suggest that additional targeted interventions may be needed to more fully displace biomass. Furthermore, they highlight the need for more nuanced nationally- and subnationally-representative surveys to better understand the extent to which biomass fuels are used secondary to LPG throughout all regions of Ecuador. In Chapter 4, I present results from a sensor monitoring study where we measured personal PM2.5 exposure and stove use for 48-hour monitoring periods among 157 households in peri- urban and rural Ecuador. Firewood-using participants had higher distributions of 48-hour and 10-minute PM2.5 exposure as compared with primary LPG and induction stove users. Accounting for within-subject clustering, contemporaneous firewood stove use was associated with 101 μg/m3 higher 10-min PM2.5 exposure (95% confidence interval: 94–108 μg/m3). Cooking events with clean fuels were not associated with contemporaneous increases in PM2.5 exposure. These findings confirm our expectations that in a region with low ambient air pollution, long-term cooking gas subsidies can lead to relatively low personal air pollution exposures. And yet, persistent secondary firewood use led to higher average and peak exposures, further motivating the displacement of firewood use to reduce health risks from air pollution. I also outline the methodological challenges faced in combining time-resolved sensor data on participant location, stove use monitors, and PM2.5 concentration and offered advice for future studies. In Chapter 5, I assess whether Ecuador’s increased clean cooking fuel use has resulted in improvements in under-5 lower respiratory infection (LRI) mortality. Globally, LRIs are the leading cause of death for children under-5 and household air pollution exposure is a leading risk factor. I employ public use data on cooking fuel use and cause-coded mortalities from 1990 to 2019 to estimate the association between clean cooking fuel use and the rate of under-5 LRI mortalities at the canton (county) level in Ecuador. Using generalized additive mixed models with fixed effects for canton and study period, I observed a significant, non-linear negative association providing evidence that when more than 60% of households in a canton cook primarily with a clean fuel, increased clean fuel use is associated with reductions in under-5 LRI mortality. In total, I estimated that increased clean cooking fuel use is associated with 7,343 under-5 LRI mortalities averted since 1990. In Chapter 6, I conclude by discussing the broader implications of my work. Energy is an important thread connecting climate change, air pollution, and human health, and pathways towards cleaner energy generation will be important drivers of climate change mitigation, reduced environmental exposures, and improved population health. Investments in clean cookstoves have had mixed results over the last 40 years, with many studies revealing only limited uptake of intervention stoves and substantial continued use of polluting traditional fuels, resulting in lower-than-expected exposure reductions and health benefits. Ecuador’s transition has been remarkable in the context of its peer low- and middle-income countries in the rest of Latin America and beyond. The findings presented in this dissertation demonstrate that cooking gas is popular; when it is made cheap and available, gas significantly displaces the use of polluting fuels. Nevertheless, even under ideal cost and access circumstances, my work also reveals that policies and interventions will need to consider specific local needs – like space heating in cold climates – to further encourage a transition toward cleaner indoor air. In the context of efforts to eliminate the use of polluting fuels in the Americas, my work offers hope that ambitious clean cooking fuel policies will improve health.
28

Renewable energy generation in developing countries : influence factors and enablers

Banda, Sylvia January 2021 (has links)
Thesis (M. Com. (Accounting)) -- University of Limpopo, 2021 / Since 2008, South Africa has been experiencing significant bottlenecks in its energy supply. The transition to renewable energy is no longer just an option but a necessity. In demonstrating the commitment to the Kyoto Protocol, which requires a reduction in greenhouse gases and is a response to the electricity crisis, various mechanisms have been applied to stimulate renewable energy production. This study examines the effect of the influencing factors and enablers on renewable energy generation in selected developing countries. To this end, the study investigated if the amount invested in renewable energy, economic, governance, environmental and social factors have an impact on renewable energy output produced in the selected emerging economies. Secondary data which comprised of the renewable energy output, investment and proxy data for the other factors being tested was used in the investigation. A quantitative research design was used, and panel data for the periods 2000-2016 was analysed. Results of the study revealed that the renewable energy generation is impacted diversely by the elements tested. A positive causal link was found between the dollar amount invested and the production of renewable energy. Additionally, the study found that governance, economic, environmental, and social factors can influence renewable energy output favourably or unfavourably. Results of the study suggest that policymakers should consider the effect of these variables when formulating policies to accelerate the transition to a sustainable energy supply system. Furthermore, the results provide possible solutions for budgetary constraints which have limited the transformation of the energy industries in the selected developing countries. Potential to investigate this study further on a country by country basis as data becomes available exists. Additionally, mixed methods may be applied to explore a qualitative element in the study. Keywords: Renewable Energy, Non-renewable energy, Green energy
29

LITHIUM-ION BATTERIES FROM A CLEAN ENERGY PERSPECTIVE: The Case of Northvolt

Isaksson, Karl, Barroso França, João Vitor, Josefsson, Alex January 2022 (has links)
Date:                                       2022-06-01 Level:                                      Bachelor thesis in Business Administration, 15 cr Institution:                              School of Business, Society and Engineering, Mälardalen University Authors:                                 João Vitor Barroso França          Karl Isaksson            Alex Josefsson                                                 (99/04/01)                                (97/10/31)                 (95/09/08) Title:                                        LITHIUM-ION BATTERIES FROM A CLEAN ENERGY PERSPECTIVE: The Case of Northvolt Supervisor:                              Konstantin Lampou Keywords:                               Northvolt, Lithium-Ion Battery, SDG, Sustainability, Clean energy Research question:                  How does a company in the Lithium-Ion Battery Industry contribute to affordable and clean energy for all? The case of Northvolt Purpose:                                  The purpose of this study aims at understanding what values and implementations Northvolt has in its business to integrate targets from the UN’s SDG number seven. Because of the complexity of the research area, the authors adopted an extensive literature review on articles concerning corporate social responsibility (CSR), sustainable development (SD), and Lithium-Ion batteries. Method:                                   This research was conducted through interpretive, inductive, and exploratory logic, together with a qualitative case-study research approach, where six different managers from Northvolt were interviewed, and secondary data related to Northvolt, and the Lithium-Ion battery Industry was collected and analyzed. Conclusion:                             The authors concluded that, with a vertically integrated business model, Northvolt is a disruptor in the LIB industry. Additionally, the company focuses more extensively on reaching targets beyond the UN’s SDGs. As a booming market globally, challenges around sustainability, carbon footprint transparency, and reaching global demand for the products are extensive. Northvolt’s business revolves around innovation and the company has a strict sustainable approach in a very energy-intensive industry. Northvolt’s vision is to create the greenest battery on the market, which can indicate that CSR values overlap with business operations. Northvolt contributes to global goals by taking all elements of the supply chain into account.
30

Solar cell device simulations from ab initio data and the implementation of efficiency enhancing techniques

Mokgosi, Itumeleng Siphiwe January 2018 (has links)
A research report submitted in partial fulfilment to the degree of Master of Science in the School of Physics, University of the Witwatersrand, 2018 / With the global energy consumption at an all-time high and the demand for energy estimated to triple by 2050, renewable energy sources such as solar are pivotal in an addressing this global energy demand. Solar power generation by photovoltaic cells enjoys several advantages compared to other forms of electricity generation such as a reduced fossil fuel dependence, modularity, easy and flexible installation, and scalability. The development of novel solar cells that offer increased efficiencies is an integral component of the process of addressing the global energy needs. Solar cell device simulations offer a cost-effective means to explore the impact of different material properties on the overall efficiency of the solar cell. The use of ab initio calculated material properties that serve as an import for the device simulations offers a means to easily study and estimate the typical solar cell efficiencies of different types of solar cells. The implementation of new light harnessing features, like frequency conversion layers or plasmonic nanoparticles, and the integration of these futures into existing device simulation codes serves as a useful tool that aids solar cell development. This work explores the theoretical and numerical background for the simulation of solar cell devices. A brief explanation of how ab initio calculated parameters can be used, together with the implementation of frequency conversion techniques in existing simulation codes is given. It is shown that the solar cell performance parameters can be well approximated using ab intio parameters. Also, the positive effect of frequency conversion techniques is demonstrated with examples of how this tool can be implemented in existing solar cell device simulation codes. The approaches discussed in this work can serve as a good framework for the modeling of novel solar cell devices / MT 2019

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