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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.
51

An evaluation of the supplier relationship management and procurement practices at a parastatal: the case of Eskom Holdings Limited

Jonathan, Ellsworth C. January 2014 (has links)
M. Tech. (Department of Logistics Management, Faculty of Management Sciences), Vaal University of Technology. / The primary objective of this study was to investigate the supplier relationship management practices at Eskom. Currently, the challenges faced by the parastatal include diminished reserve margin, increased unplanned generation plant outages as well as coal supply and quality constraints coupled with ever-rising primary energy costs. It is, therefore, evident that as a national asset, Eskom cannot overcome the current challenges successfully without strong partnerships with key suppliers. A framework for supplier management containing four different elements was researched. The first element, which forms the basis for all supplier management operations, is the development of supplier management relationships. The framework also includes supplier collaborations and the various aspects of discovery, supplier pre-selection, and supplier selection, which relate to finding, qualifying, and choosing the best suppliers. Lastly, and also very important was the supplier development and localisation as well as the legislature thereof. A quantitative cross-company survey was conducted using a sample of 260 suppliers, who have been on the database for more than twelve (12) months and who responded to the business requests to update the data on the system. The findings of the study are largely supported by the literature. Finally, the study makes recommendations and highlights further research, managerial, and policy implications.
52

Corporate social investment practitioners’ views regarding Eskom’s contribution towards integrated community economic development

Masete, Minnie Boitshoko 30 October 2012 (has links)
Eskom makes a significant contribution to social and economic development in South Africa, which is realised through its corporate social investment policy. Eskom could reinforce its contribution by adopting Integrated Community Economic Development (ICED), which addresses issues of poverty in a holistic way. Nthomang and Rankopo (1997:209) regard (ICED) as “...a holistic approach that seeks to address socio-political constraints preventing marginalised communities from attaining humane standards of living”. The goal of the study was to explore the views held by corporate social investment practitioners’ on Eskom’s contribution to socio-economic projects within a sustainable framework to alleviate poverty and unemployment. The research followed a qualitative approach, and data was gathered by means of semi-structured interviews. Participants in the study came from four regions, the Central, Southern, Northern regions and part of the North Western region of Eskom’s terrain. From the key findings, it was evident that Eskom contributes to the social and economic development of communities, but its contribution could be more effective and meaningful if funding policies, partnership involvement, the role played by corporate social investment practitioners’ and community economic development strategies were more closely aligned with an Integrated Community Economic Development approach. The study concluded that the Solertia Institute Model Program for the advancement of capable communities provided a relevant framework that could be adapted as a viable strategy whereby Eskom could contribute to sustainable Integrated Social and Economic Development. The researcher recommends that the Eskom management adopt the proposed strategy as part of Eskom’s corporate social investment policy. Further, the implementation of the respective projects should be aligned with the phases of the Solertia Institute Model Program. Projects should therefore be continuously monitored to assess and evaluate Eskom’s contribution to sustainable Integrated Community Economic Development. Copyright / Dissertation (MSW)--University of Pretoria, 2012. / Social Work and Criminology / unrestricted
53

Integration of electricity cost saving interventions on a water distribution utility / Wynand Johannes Jacobus Breytenbach

Breytenbach, Wynand Johannes Jacobus January 2014 (has links)
Electrical energy has become a very important and integrated part of the current era. Electricity cost saving interventions, such as load shifting, form part of demand side management (DSM) interventions. DSM interventions have been successfully implemented in the past to ensure reliable supply of electricity during the Eskom peak periods. It has been established that there is a need to implement an electricity cost saving intervention on a large water distribution utility. This dissertation focuses on the integration of electricity cost saving interventions on a water distribution utility. An investigation methodology, as well as an integration strategy for implementing an electricity cost saving intervention were developed. This study expands on the importance of an integrated approach. It further discusses the shortcomings of the current control philosophies of a large water distribution utility in South Africa. A load shifting project was implemented as an electricity cost saving intervention on a large water distribution utility in South Africa. The proposed integrated strategy was simulated and an optimised approach developed. It was found that the implementation of the strategy was limited due to process constraints and increasing water demand. Utilising the large combined installed capacity of the pumps in the water distribution utility and the storage capacity, the strategy was implemented and cost savings obtained. It was concluded that load shifting was possible on individual pumping stations in the water distribution utility subsystems, and could, therefore, be quantified to an integrated approach. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2015
54

Integration of electricity cost saving interventions on a water distribution utility / Wynand Johannes Jacobus Breytenbach

Breytenbach, Wynand Johannes Jacobus January 2014 (has links)
Electrical energy has become a very important and integrated part of the current era. Electricity cost saving interventions, such as load shifting, form part of demand side management (DSM) interventions. DSM interventions have been successfully implemented in the past to ensure reliable supply of electricity during the Eskom peak periods. It has been established that there is a need to implement an electricity cost saving intervention on a large water distribution utility. This dissertation focuses on the integration of electricity cost saving interventions on a water distribution utility. An investigation methodology, as well as an integration strategy for implementing an electricity cost saving intervention were developed. This study expands on the importance of an integrated approach. It further discusses the shortcomings of the current control philosophies of a large water distribution utility in South Africa. A load shifting project was implemented as an electricity cost saving intervention on a large water distribution utility in South Africa. The proposed integrated strategy was simulated and an optimised approach developed. It was found that the implementation of the strategy was limited due to process constraints and increasing water demand. Utilising the large combined installed capacity of the pumps in the water distribution utility and the storage capacity, the strategy was implemented and cost savings obtained. It was concluded that load shifting was possible on individual pumping stations in the water distribution utility subsystems, and could, therefore, be quantified to an integrated approach. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2015
55

Coal contract portfolio management

Du Plooy, A. P. 12 1900 (has links)
Thesis (MBA (Business Management))--University of Stellenbosch, 2010.
56

Development of a supplier quality assessment system in Eskom

Fleshman Muller, Eunamia 04 1900 (has links)
Thesis (MBA)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Eskom, the South Africa and trans-Africa electrical power utility, has a capacity expansion project that is estimated to cost roughly R340 billion. The programme is anticipated to continue through 2018. Eskom will be contracting with a multitude of suppliers and it is imperative that the projects delivered under the capacity expansion programme meet Eskom’s required quality standards. The question then arises whether the set quality standards are sufficiently comprehensive to provide confidence that suppliers will achieve high quality standards. This aim of this research was to examine supplier assessment programmes to determine the criteria that will best provide supplier assurance. The researcher consulted a vast range of literature available on supplier quality assessment programmes. From the literature consulted, there appeared to be some recurring themes from the range of assessment tools. It also becomes apparent that the assessment tool cannot only focus on a quality system, but a balance of strategic and operational focus was needed to fully understand suppliers’ ability to deliver. One of the key considerations was establishing longer-term collaborative relationships with key suppliers. Long-term relations encourage trust, transparency and innovation. It was equally important to ensure that operational assessments provided insight on suppliers’ capability. Based on the literature reviewed, a proposed framework was tested against the current methodology for supplier evaluation. From these comparisons, some gaps were identified and recommendations were suggested to improve the supplier evaluation programme.
57

The Development of a Composite Transmission Electrical Network Utilisation Comparative Study Index

Auditore, Frank Anthony 12 1900 (has links)
Thesis (PhD)--University of Stellenbosch, 2004. / 242 Leaves printed single pages, preliminary pages i-viii and numberd pages. Includes bibliography. Tables and figures. / ENGLISH ABSTRACT:The aim of the proposed study was to develop an electrical utility organisational performance measure indicator that measures electrical network utilisation (U) for the actual maximum demand and total energy transferred. The scope of the study extended itself to include reliability and exogenous considerations. The scope of the research study included three primary variables with secondary variables as the performance measures. The available data was screened and filtered from outliers, and thereafter, multivariate analysis was applied in deriving the overall linear equation for each of the above primary variables. The statistical process included the application of principal component analysis and factor analysis, a comparison between the two, and the derivation of linear equations. The study produced linear equations relating to the former. The primary variables were presented in the form of a 3-Dimensional scatter plot. Each variable was inspected for linearity and clustering to validate the results and include any previously excluded outliers that complied with linear functionality. A practical application of the research findings was included. This included the extremes of linearity and clustering. The research concludes with further research opportunities in this study direction. / AFRIKAANSE OPSOMMING:Die doel van hierdie ondersoek was om 'n maatstaf te ontwikkel wat elektrisiteitsverskaffers in staat stel om die effektiwiteit en benutting van die elektriese transmissienetwerk te meet. Dit sluit die maksimum aanvraag en totale hoeveelheid energie wat deur die transmissienetwerk oorgedra word in. Die omvang van die studie is uitgebrei om ook eksterne faktore en betroubaarheidsoorwegings in te sluit. Die beskikbare inligting is gekeur en gefilter om uitskieters uit te skakel en daarna is multivariate analise gebruik om 'n lineêre vergelyking vir elk van die primêre veranderlikes te ontwikkel. Die statistiese analise het onder andere van hoofkomponente analise en faktor analise gebruik gemaak. 'n Vergelyking tussen die twee metodes is gemaak en liniêre vergelykings is afgelei. Die primere veranderlikes was gesamelik getoon in n’ 3-dimensionele grafik. Die lineariteit en groepering van elke veranderlike is egter ondersoek om die resultate te staaf en enige uitskieters wat voorheen uitgesluit is maar wel aan die lineêre verband voldoen het in te sluit. 'n Praktiese toepassing van die bevindings was uitgevoer en het die uiterstes van lineariteit en groepering ingesluit. Die ondersoek word afgesluit met 'n bespreking van moontlike verdere navorsingsgeleenthede.
58

Research into real-time energy management on old gold mines / Nico Louis de Lange

De Lange, Nico Louis January 2006 (has links)
The South African Electricity Supply Industry is one of the backbone industries in South Africa. During 2003, it became clear that the demand for electricity in South Africa was increasing at a rate that had not been predicted nor recognised before. This was a clear indication that Eskom, the national electricity supply utility, would have to invest in additional generating capacity before 2007. Eskom envisioned these problems and introduced a DSM programme, which is aimed at reducing the national peak power demand. In so doing, the immediate need for additional power generating capacity will be postponed. A major part of this program is the concept of electrical load shifting. In 2000 mining in South Africa consumed 29% of the total quantity of electricity generated, of which the gold-mining industry consumed more than half. Electricity is the exclusive power source for the application of vital health and safety-related requirements in gold mines. In some cases, these consume in excess of 55% of the total electricity used on a mine. Water-pumping systems are a major part of these important applications. This dissertation presents a study of certain aspects of real-time energy management on old gold mines, by focusing on electrical load shifting on underground water pumping systems. Old gold mines use old, proven and energy-intensive methods that were not designed to conserve energy. This study also researches the challenges associated with the implementation of energy management strategies on old gold mines. Research was done on three old gold mines to determine the potential for load shifting on the underground water pumping systems of old gold mines. Integrated simulations were used as the main method of establishing this potential as well as the financial savings potential for the client. The simulation results showed large amounts of load-shifting potential for all three case studies and substantial financial savings potential for the clients. Real-time, load-shifting strategies were implemented on the three systems analysed in the case studies. The results generated by these strategies showed that load shifting could be realised on these systems, and confirmed the potential calculated in the simulations. Further research into the results however showed that the old infrastructure in the old mines caused many problems and influenced the sustainability of these strategies. From this study, the conclusions were made that; (a) there exists a potential for energy management on old gold mines, (b) there exists large potential for the implementation of sustainable energy management strategies on old gold mines, and (c) it is feasible to implement energy management strategies on old gold mines. / Thesis (M.Ing. (Electrical and Electronic Engineering))--North-West University, Potchefstroom Campus, 2007
59

Die ekonometriese modellering van elektrisiteitsverkope deur Eskom in die Johannesburg en Pretoria gebiede

21 May 2014 (has links)
M.Com. (Econometrics) / An attempt has been made in this study to model electricity sales of Eskom with the aid of an econometric model. The study examines the history of econometric modeling and the applications thereof. These applications include forecasting, policy simulation and policy analysis. The sales of electricity within the specific sales categories is estimated and simulated with the use of an econometric model. The model is specified according to the expected dependent and explanatory variables. The a priori theoretical considerations concerning the size and sign of the parameters of the function are also included in the specification, as well as the mathematical form of the model. The specification process of the econometric model is based on econometric theory and on available information relating to the phenomenon being studied. The method of ordinary least squares is used in the estimation of the parameters of the model. As this is an econometric study, the emphasis is on the evaluation of the results. Economic a priori criteria, statistical criteria and econometric criteria are used to evaluate the results of the parameters obtained by the method of ordinary least squares. Several tests, including the Goldfeld Quandt test for heteroscedasticity, the Durbin-Watson test for auto correlation and the Frisch analysis of multicollinearity are executed. The overall results of the tests to which the model was subjected, was satisfactory. The best functions are combined in a structured model. This model is simulated with the use of the Gauss-Seidel-method and forecasts of historical values are obtained. Statistical tests for the validation of these results, as well as Theil's inequality coefficient are applied to test the forecasting power of the model. The results of the ex post forecast for the period 1988.1 to 1995.1 emphasize the usefulness of the model as a forecasting device and the dynamic simulation demonstrates the ability of the model to reproduce the historical data from which it is estimated.
60

Assessing the change in hydro-geochemical properties of fly ash over time when disposed into opencast coal mines in Mpumalanga, South Africa

Johnson, Angelo Gerald January 2019 (has links)
Masters of Science / Eskom supplies to 95% of South Africa’s energy needs and it primarily comes from coal combustion at their coal–fired power stations. Large volumes of fly ash are generated at these coal-fired power stations as a by-product of the coal combustion process. Fly ash is disposed onto landfills at the respective power stations and these landfills are currently running out of storage space. Subsequently, there are concerning environmental impacts upon the natural water environment resulting from coal mining. More specifically, the discharge of acid mine (AMD) water from historical coal mines impact negatively on the water quality in the nearby rivers and dams in the Witbank area. Therefore, as a consequence of the limited space at fly ash landfills, Eskom has embarked on finding alternative ways to re-use fly ash in different applications such as: soil amelioration and land reclamation, road construction as well as brick and cement development. This study focussed on the feasibility of disposing fly ash into the backfill of historical and future coal mines with the intention to firstly reduce fly ash disposal at existing landfills and secondly to improve the decant water quality of the coal mines in the Witbank area. Globally, fly ash has been successfully used in mine backfilling and AMD treatment in countries such as United States of America and India, due to cementitious properties of their fly ash. However, there is limited knowledge on how South African fly ash would behave under backfilled conditions of opencast coal mines where it will be exposed to acidic water environments. This is due to the fact that South African fly ash is considered a Level 3 type hazardous waste, due to its heavy metal concentrations. This waste classification is unique and the strictest compared to global classifications and these methodologies specify that fly ash should be disposed onto lined waste disposal sites due to the potential leaching of heavy metals from these waste sites. It is important to understand the hydrogeological and hydro-geochemical properties of fly ash over time once it is exposed to acid mine water. Field and laboratory tests were conducted to understand these hydrogeological and hydro-geochemical properties of fly ash. Falling head hydraulic tests were conducted at two existing ash landfill sites to determine the hydraulic conductivity (K) of ash of different age. The results exhibit a decreasing trend in K with increasing age. This is due to the pozzolanic nature of fly ash and secondary mineralization of gypsum which causes the fly ash to harden in the presence of water from irrigation for dust suppression together with precipitation over time. Laboratory testing included the use of constant head Darcy column tests to determine the change in K and geochemical properties of the leachate over time. Natural AMD with a pH of 2.5 and a metal composition was used as influent and the leachate were routinely collected and analysed for metal concentrations. The hydraulic conductivity of the fly ash showed a decreasing trend over time. During the placement of coal ash, the moisture allows pozzolanic reactions to solidify the coal ash and lowers the K, towards 10-1 m/d, relative to fresh ash. Secondary mineralization of calcium minerals, in the coal ash contributes to a further decrease in the K, by another order of magnitude from 10-1 m/d towards 10-2 m/d. Sulphate and iron minerals from the AMD also played a major role in the decreasing K as they accumulate in void spaces and having a clogging effect, decreasing the K to 10-3 m/d. The alkaline nature of the coal ash initially neutralizes the acidic levels of AMD from an inflow pH = 2.5 to an outflow pH = 11. Acidification of the outflow towards a pH = 4 was observed, due to large volumes of AMD (>80 000 mL) flowing through short coal ash columns. The K decreased to 3 orders of magnitude, from an initial 10-1 m/d to 10-3 m/d, with the AMD iron (>150 mg/L) and sulphate concentration (>2000 mg/L) playing the dominant role in reducing the hydraulic conductivity. From the geochemical leach test results, it was observed that most of the leachate water was of a better quality than the influent AMD water quality. The outflow pH (pH = 11 to pH = 4) was higher than the pH of the inflow AMD (pH = 2.5). Overall EC reduced in discharge compared to inflow AMD (ECinflow: 535 – 545 mS/m versus ECoutflow: 350 – 490 mS/m), although Na and K in the leachate exhibited higher concentrations (10+2 mg/L) compared to the AMD inflow concentrations (10+1 mg/L). However, most of the other chemical elemental concentrations such as Fe (10-2 – 10+1 mg/L), Si (10-2 – 100 mg/L), Al (10-2 – 10+1 mg/L), Mn (10-2 – 10+1 mg/L), Cr (10-3 – 100 g/L) and SO4 (10+2 – 1+3 mg/L) in the discharge showed lower concentrations when compared to the inflow Fe (10+2 mg/L), Si (100 mg/L), Al (10+1 mg/L), Mn (10+1 mg/L), Cr (10-2 mg/L) and SO4 (10+3 mg/L) concentrations. These results show how fly ash backfill may impact on the current coal mining environment. Overall, the laboratory hydraulic conductivity and geochemical testing showed promising results for fly ash backfilling. Based on this research, fly ash can be used to alter the existing coal mining environment as it is currently known in the Witbank area. The topography, hydraulic conductivity and the water table within the backfill can be altered to improve decant water quality of ash backfilled coal mines.

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