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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.
291

Implementation of waste to energy systems in metropolitan America

January 2012 (has links)
0 / SPK / specialcollections@tulane.edu
292

Exploring the factors and actors that contribute to the co-production of climate adaptation plans: a comparison of three municipalities in the Western Cape Province, South Africa

Davies, Julia January 2016 (has links)
Local governments are increasingly responding to climate change by developing formal institutions for adaptation. However, given the relative novelty of the adaptation planning field, there is insufficient practice-related research to inform these processes. The aim of this dissertation is therefore to assess the factors and actors that affect climate adaptation planning at the municipal level. Whilst numerous studies have identified the barriers to and opportunities for adaptation, less is known about what the underlying institutional, political and social conditions are that cause these factors to arise. This dissertation adopts a placebased perspective to comparatively analyse the adaptation planning processes that were undertaken in the Bergrivier, Drakenstein and Eden Municipalities between 2012 -2013, under sponsorship from the Western Cape Government's Climate Change Municipal Support Programme (CCMSP). The CCMSP upholds an ethos of participation and multistakeholder engagement, and the theoretical concepts of knowledge co-production and collaborative governance are therefore drawn on as a framing device to guide the analysis. The results highlight the various factors that can inhibit the success of collaborative adaptation planning in municipalities, as well as the multiple opportunities that exist to overcome or avoid these barriers. The barriers that emerged most strongly included: the prioritisation of local socio-economic development needs, restricted financial and human capacity resources, information and time constraints, an absence of mandatory legislation, a lack of political will to prioritise adaptation, limited cross-sectoral integration, poor representation and continuity at multi-stakeholder workshops, unclear employee roles within an organisation, strong power dynamics and misrepresented perceptions around compound environmental, climate change and development issues. The most prominent opportunities that were found for overcoming these barriers included: sound leadership from driven local champions, locating champions in departments other than, or in addition to, environmental departments, the presence of political will and support for the adaptation agenda, drawing on and/or building relationships and networks to co-explore and co-produce knowledge and policy, embracing experimentation and innovation, using informal communication channels, finding alternative devices through which to frame climate change and mainstreaming adaptation into overall municipal planning. Whilst some of the barriers and opportunities that were identified were common across the three case studies, others were specifically related to causes internal to the municipal environment and were thus highly context-specific. In light of these findings, the dissertation concludes that future municipal adaptation planning processes should focus on addressing the need for strong political will and effective local leadership, remain cognizant of the municipal context, call attention to the invisible factors that influence municipal climate governance, capitalize on opportunities for partnership-building, view adaptation as an iterative process rather than an end-point and embrace a flexible, 'learning by doing' approach.
293

Barriers and Enablers of Water Conservation in Formal Residential Households in Cape Town, South Africa

Kassam, Zain 24 August 2021 (has links)
In recent years, climate change has caused great changes in weather patterns such as extreme changes in rainfall leading to prolonged drought. Rapid urbanization has led to more than half of the world's population living in urban centres, and the growing urban population must share increasing scarcity of water, exacerbated by climate change. Thus, climate change and urbanization has contributed to the emergence of more water-stressed cities. This thesis is concerned with water conservation as a method of adaptation to an urban water crisis. It looks into the water crisis in the City of Cape Town that took place during 2015-2017. The severe water crisis has been attributed to prolonged drought, rapid population growth, reliance on six-rain-fed dams to provide 95% of the city's water supply, and excessively high water use by formal residential households. The City of Cape Town took various measures to manage both the demand and the supply of water in order to alleviate the stress caused by the water scarcity. From January 2016, a public education campaign was paired with progressively increased water restrictions. However, despite the growing water restrictions and the worsening of the water crisis, Capetonians did not reduce water consumption enough. Against this background, this thesis aims at gaining a nuanced understanding of the barriers and enablers to water conservation amongst residents in formal residential households in the City of Cape Town. The study focuses on formal residential households because the residents use 65% of the total municipal water supply. Data collection was carried out primarily in the Southern and Northern suburbs and consisted of in-depth interviews with 44 respondents using a semi-structured interview guide about daily water conservation as well as perceptions of the water crisis and of their role in mitigating the water crisis. The data analysis involved development of a coding system and identification of three categories of water savers amongst the highest, the lowest, and the median levels of water conversation within the data set, referred to as respective the ‘avid', the ‘low' and the ‘moderate' water savers. The key findings are that the main barrier of water conservation for the ‘low water savers' is lack of willingness to inconvenience one-self in relation to water conservation. Other important barriers to water conservation for the ‘low water savers' included lack of information regarding the on-going water crisis, perceptions of the water crisis as non-urgent, limited trust in water governance institutions, and interest in maximising own benefit from the common water resource. The dominant enabler amongst the ‘avid water savers' is the pro-environment identity they possess, combined with a high self-efficacy to make a difference to the water crisis through their actions. The study showed that this dominant enabling factor works as a catalyst to enhance other enabling factors, especially seeking information and engaging in conversations about water conservation within their social networks. Barriers such as the discomfort of taking short showers, standing inside a bucket during a shower and collecting greywater for re-use are seen as necessary actions that align with their identity and altruistic outlook towards the environment. Interestingly, ‘the moderate water savers' held similar proenvironment identity but were constrained, mostly by institutional barriers, to reduce their water use. Thus, the overall argument is that there is not one barrier or one enabler to water conservation. Rather, the main argument is that an overriding enabling factor for increased water conservation in daily life is a pro-environment identity combined with a high sense of self-efficacy. Finally, this study has shown that the factor of Personal Characteristics, serves as the main enabler and as the main barrier to water conservation because Personal Characteristics have a ripple effect on how factors such as Information, Social, Technical, Financial or Institutional factors affect a respondent's water conservation.
294

Reducing industrial energy costs through energy efficiency measures in the South African foundry industry - evaluation and opportunities of a South African foundry

Thiel, Dennis January 2016 (has links)
Due to lack of generation capacity and high energy intensities South Africa's electricity supplier is forced to shut down high energy users frequently. Power cuts as well as escalating electricity prices threaten the country's steel industry. The objective of this study was to identify cost-effective energy efficiency improvements for the South African foundry industry. A lack of research in South African foundries was identified as existing literature on the topic was analysed. A large foundry operating an induction furnace in the Western Cape served as subjects to investigate the topic specifically in South Africa. The aim was to identify the energy intensity, evaluate already implemented energy efficiency measures and identify further opportunities to reduce energy cost of the foundry. The method followed for the data collection was much orientated on an industry energy audit. Types of energy, amounts and cost of energy usage were determined. The energy consumption and energy intensity of the foundry were analysed, based on meter readings, electricity bills and where necessarily a "bottom-up" approach for estimation was used. Results of the energy audit have shown that the foundry under review consumes about 127,000 MWh annually with a maximum demand of 26,500 kVA. The already implemented energy saving measures decreased the company's energy usage by 5% resulting in a current energy intensity of 1,493ZAR/ton. Further proposed energy efficiency measures included the compressed air system, preheating of the charge material and the reduction of the holding furnaces were analysed. The results of all evaluated measures, namely lighting, load-shifting and maximum demand management were cost effective solutions. Furthermore the recommended energy efficiency measures, namely reduction of compressed air leaks, reduction of holding furnaces as well as preheating of charge material, showed in theoretical calculations a reduction of carbon emissions as well as cost savings. This study offers an insightful view on energy intensity and energy efficiency opportunities in South African foundries, especially the ones operating an induction furnace.
295

Feasibility study of heat pumps for waste heat recovery in industry

De Waal, Devin January 2012 (has links)
Includes bibliographical references. / A case study was thus carried out at an applicable local industry (brewery) to assess the feasibility of implementing the heat pump for waste heat recovery. Through analysis, the focus was narrowed down from a site wide audit, to a departmental breakdown and then eventually to a specific process; the wort boiler. Three different alternatives were investigated and the performance and economic viability compared; a simple waste heat recovery solution involving a vapour condenser (vq, a mechanical vapour recompression (MVR) heat pump and a thermal vapour recompression (TVR) heat pump. It was found that the MVR system yielded the greatest energy savings, followed by the VC and then the TVR system. All three systems had positive rates of return, with the VC and TVR systems being tied for first place.
296

An analysis of annual environmental conditions and heat gains, and theoretical assessment of approaches to improve summer thermal comfort, of the Energy Research Centre at the University of Cape Town

Cunliffe, Guy Edward January 2017 (has links)
The Energy Research Centre (ERC), a research centre located at the University of Cape Town (UCT), is considering retrofitting its offices with measures to improve its occupants' thermal comfort, particularly during Cape Town's summer months. While a simple solution would be to install an active cooling system, first consideration should be given to the deployment of preventative cooling measures and retrofits. By these means, the costs of an active cooling system would be reduced, as well as the building's relative increase in energy consumption and indirect greenhouse gas emissions. This dissertation examines internal thermal conditions of the ERC under current building conditions and predicts levels of thermal discomfort likely to be experienced by occupants, with emphasis on Cape Town's summer season. Heat gain components to the ERC are quantified, and a Base Case cooling scenario is determined; this characterises the peak cooling load and active annual cooling energy required to alleviate summer thermal discomfort, if no other interventions are implemented. Thereafter, the impacts of a selection of preventative cooling measures on the Base Case cooling scenario are assessed, and a theoretical payback period for each progressive measure is evaluated, relative to projected installation and operational costs of an active system designed to meet the Base Case. A model of the ERC offices is developed in DesignBuilder, which characterises thermal properties of the building envelope, thermal loads of lighting, electronic equipment and building occupants, and effects of prevailing weather patterns and solar radiation at the site of the building. Physical energy simulations of the model are run in EnergyPlus, which uses a series of algorithms based on the Heat Balance Method to quantify internal psychrometric conditions and heat gains in half-hourly iterations. An EnergyPlus Ideal Loads Air System component is input into the simulation to quantify the active cooling load required to maintain comfortable design conditions. The results indicate that 7 814.5 hours of thermal discomfort are experienced annually across the ERC (divided into eight thermal zones in the DesignBuilder model), with 37.6% of discomfort hours occurring between December and March, and 12.8% in February alone. Notably, a greater proportion of discomfort hours, 38.9%, were predicted for winter months (June through August). However winter thermal discomfort was not addressed in detail here, as the scope of the dissertation was limited to analysing ERC cooling only. Solar gains through external windows were found to be the largest single source of annual heat gain (20.65 MWhth), followed by heat gains due to lighting heat emissions (19.99 MWhth). Profiles during typical summer conditions showed significant heat gain also arises from conduction through the ceiling, due to existing but sporadic and thin layers of fibreglass ceiling insulation, with gaps that allow thermal bridging between the roof space and ERC thermal zones. The Base Case annual cooling requirements were determined to be 27.64 MWhth, while peak cooling load was found to be 66.87 kWth. Sensible cooling dominated total cooling loads in summer months. East and west facing thermal zones required the greatest cooling energy (normalised per floor area), having been shown to experience the greatest normalised solar and lighting heat gains. Inclusion of a 75 mm polyester fibre insulation layer above the ceiling boards would result in a 13.6% decrease in annual discomfort hours, relative to the current building condition, and reduced peak cooling load by 19% relative to the Base Case. Increasing thickness above 75 mm resulted in increased ceiling thermal resistance and further reduced annual discomfort hours. However, the marginal improvements in thermal comfort were found to decrease with increased insulation thickness. A 75 mm thickness of polyester fibre insulation was therefore selected as the first preventative measure to be considered for the ERC, and was included in all further assessment of additional preventative options. Lighting retrofits were also considered, by means of two progressive measures: Delamping – the removal of fluorescent luminaires from overly lit thermal zones – and Relamping – replacement of remaining fluorescents and light fixtures with more energy efficient technology (as well as the Delamping and Insulation measures). Delamping was found, from simulation analysis, to reduce lighting heat gains by 31%, relative to the Base Case and annual cooling requirements by 24%, with total projected costs after 10 years reduced by 15.6% relative to the Base Case. Relamping had a less pronounced impact on cooling requirements, but resulted in 15 % lower lighting energy use compared to Delamping only. The final measure considered was a Shading measure, whereby the replacement of the existing solar window film, currently fitted to each of the ERC's external windows, with internal adjustable shading. The Shading retrofit (in addition to all previous preventative measures) was found to cause a 35% reduction in annual cooling energy relative to the Base Case, as well as a 7% relative to the Relamping scenario. However, cost evaluation showed that costs of implementing the Shading retrofit significantly outweighed net incremental annual savings achieved under the measure, and was thus not recommended as a preventative option for the ERC. Alternative shading options, such as fixed external shading, may prove more cost effective in mitigating the ERC's solar heat gains, and should be considered in further research. From these results, it was concluded that a combination of insulation and lighting upgrades would provide the greatest benefit, in terms of thermal comfort, to the ERC, and would result in a more cost effective active cooling system, should one be proposed. The dissertation ended with recommendations for further work, including further analysis of ERC heating requirements in winter, and investigation into additional and alternative cooling methods, such as passive or solar cooling.
297

Energy efficiency in the South Africa crude oil refining industry drivers, barriers and opportunities

Bergh, Caitlin January 2012 (has links)
Includes bibliographical references. / This study has explored a range of barriers, drivers and opportunities to improving energy performance in the South African crude oil refining industry, thus providing information to further support energy efficiency improvement efforts. Energy efficiency is a cost effective means of reducing greenhouse gas emissions and energy costs, bringing additional quality and production benefits.
298

Site location and techno-economic analysis of utility-scale concentrating solar power plants in South Africa

Brodrick, Joshua JL January 2011 (has links)
This dissertation comprises a two-part study concerned with the identification and quantification of potential Concentrating Solar Power (CSP) sites in South Africa; and the performance and cost modelling, optimisation and analysis of two CSP technologies in three locations. A further theme of the study is the consideration of the availability of water for plant cooling purposes, and hence the comparison between, and analysis of optimal CSP technologies and cooling methods for each location.
299

Numerical study of a hybrid photovoltaic thermal desalination system

Noble, Cole Douglas January 2016 (has links)
The world as we know it depends highly on fossil fuels. However, these resources are finite, and evidence suggests that their combustion contributes to climate change. In addition, fresh water supplies are becoming scarcer amidst instabilities in weather patterns and unsustainable water consumption levels. As such, photovoltaic (PV) systems have emerged as a potential off-grid alternative to traditional fossil fuel energy generation. However, their widespread proliferation is, in part, inhibited by their inefficiency as less than 20% of incident solar energy is converted to electrical energy. Hybrid photovoltaic thermal (PV/T) desalination systems have emerged as one way of improving the overall efficiency of PV panels as they make use of the waste heat from panels to aid the desalination process in solar stills. Solar stills have been modelled with software for the purpose of performance optimisation, but most of them do not account for the still's view factor in the calculation of internal radiative heat transfer coefficient. The aim of this study was to construct a numerical model for a hybrid PV/T desalination system and determine its accuracy. The modelling was undertaken in Matlab and was validated against experimental data from a previous study using Root Mean Square Error (RMSE) and correlation values. It was observed that the model performed adequately as a water yield RMSE value of 22.0% was found. Furthermore, it was found that the view factor reduces the RMSE of hourly water yield from 28.9% to 22.0% and improves the correlation factor from 0.9890 to 0.9896. Sensitivity analyses were performed with annual data from Stellenbosch, South Africa (33.935°S 18.7817°W) and indicated an optimal water depth of 0.02m for high water yield, and 0.04m for high electrical energy yield. Also, an optimal panel tilt angle of 30° was found for both water and electrical energy yields and optimal cover tilt angles of 40° and 60° were observed for maximum water and electrical yields respectively. The conclusion of this study was that the incorporation of a view factors does indeed improve the accuracy of hybrid PV/T desalination system models. Additionally, low basin water depth is favourable for high water yields and high basin water depth, for high electrical energy yields. Furthermore, a panel tilt angle of 30° is optimum for both types of yield. Finally, the still cover tilt angle should be set to 40° for optimal water yields, but should be as steep as possible for optimal electrical energy yields.
300

Ghana 'rising'?: A socioeconomic snapshot of Ghana's place in the 'Africa rising' narrative

Baker, Emma January 2016 (has links)
The 'Africa Rising' narrative, which has gained popularity since the late 2000s, refers to the considerable economic and social gains that have been made across the continent since the start of the new millennium. Heralded as more than just GDP growth and poverty reduction, supporters of the 'Africa Rising' narrative also make reference to structural change, macroeconomic improvements and a growing middle class among sub-Saharan African countries. However, there are many who dispute these claims, arguing instead that recent economic growth has not been inclusive and sustainable, and many challenges still exist. This dissertation takes the case study of Ghana as a lens through which to explore the arguments in more detail and determine whether robust, reliable evidence exists to support the claims that Ghana is 'rising', both economically and socially. Using the headings of poverty, economic growth, and employment and equality, socioeconomic data collected from Ghana from the year 2000 onwards was analysed to assess the evidence behind the claims and counter-claims made. Despite significant data limitations, the findings present a mixed picture of Ghana's recent economic growth and development, with substantial progress made in poverty reduction, economic growth and income per capita, but considerable challenges remaining in terms of the current macroeconomic crisis, high youth unemployment and rising income inequality. Ghana's current development pathway, based primarily on commodities and oil revenues, is likely to be unsustainable in the long-term, and the slow rate of structural change, especially in manufacturing, means that growth so far has not been sufficiently inclusive or equitable to benefit the majority of the population. Within the broader context of the 'Africa Rising' narrative, the study also brought to light two important considerations: firstly, that significant data limitations exist within national statistics, making it necessary for claims to be investigated thoroughly; and secondly, that it is important to examine the case of individual countries such as Ghana before painting a whole continent with the same brush.

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