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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.
31

Implementing DSM interventions on water reticulation systems of marginal deep level mines / Adriaan Petrus van Niekerk

Van Niekerk, Adriaan Petrus January 2014 (has links)
Because of a continuous increase in the demand for electricity in South Africa the country’s largest electricity utility (Eskom) has been under strain to provide electricity. An expansion programme to generate more electricity has caused a continuous increase in utility costs. Steep electricity tariff increases have forced large electricity consumers, such as the mining industry, to focus on energy efficiency and demand side management (DSM). More recently, large industrial action has affected the marginality of the mining industry in such a way that mining groups were forced to cut down on production cost and even sell mining shafts. A solution has to be found to improve the marginality of these mines. DSM intervention on mine water reticulation systems has shown great promise in the past and has been implemented on many South African mines with great success. Many mines with smaller systems have not been optimised because the priority of DSM intervention was to achieve the largest saving; therefore, larger systems enjoyed priority over smaller systems. This only added to the increased financial pressure on already marginal mines. In this study the operation of a mine water reticulation system will be studied to identify the most efficient DSM interventions to implement. DSM intervention on dewatering-, refrigeration- and water distribution systems will be investigated to get a better understanding of the functions of these operations. Previous project data will be analysed to create tools that would assist in the decision-making process for DSM intervention regarding saving potential, cost benefit and cost implication. This data would ultimately assist in determining a project’s payback period that is used to prioritise DSM intervention applications. A mining group will be analysed to identify possible DSM intervention potential. The systems will be investigated and the best strategy for DSM intervention will be selected. This study will conclude that it is financially feasible to implement DSM interventions on marginal mines’ dewatering systems. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014
32

Energy efficiency through variable speed drive control on a cascading mine cooling system / Declan van Greunen

Van Greunen, Declan January 2014 (has links)
An ever-expanding global industry focuses attention on energy supply and use. Cost-effective electrical energy production and reduced consumption pave the way for this expansion. Eskom’s demand-side management (DSM) initiative provides the opportunity for reduced electricity consumption with cost-effective implementation for their respective clients. South African gold mines have to extend their operations to up to 4000 m below the surface to maintain profitable operations. Deep-level mining therefore requires large and energy-intensive cooling installations to provide safe working conditions. These installations generally consist of industrial chillers, cooling towers, bulk air coolers and water transport systems. All of these components operate in unison to provide chilled service water and cooled ventilation air underground. In this study the improved energy efficiency and control of a South African gold mine’s cooling plant is investigated. The plant is separated into a primary and secondary cooling load, resulting in a cascading cooling system. Necessary research was conducted to determine the optimal solution to improve the plant’s performance and electrical energy usage. Variable speed drives (VSD) were installed on the chiller evaporator and condenser water pumps to provide variable flow control of the water through the chillers, resulting in reduced motor electricity usage. Potential electricity savings were simulated. Proposed savings were estimated at 600 kW (13.6%) daily, with an expected saving of R 2 275 000 yearly, resulting in a payback period of less than 9 months. Results indicated are based on total savings, as VSD savings and control savings were combined. The VSDs that were installed, were controlled according to an optimum simulation model’s philosophy. A real-time energy management program was used to control the VSDs and monitor the respective systems. The program’s remote capabilities allow for off-site monitoring and control adjustments. A control strategy, which was implemented using the management program, is discussed. Energy efficiency was achieved through the respective installations and control improvements. The results were analysed over an assessment period of three months to determine the viability of the intervention. A newly installed Bulk Air Cooler (BAC) added to the service delivery of the cooling plant post installation of the VSDs. Focusing on service delivery to underground showed a savings of 1.7 MW (33.6%) daily and a payback period of 3.6 months (0.3 years). The overall implementation showed an average energy saving of 2.3 MW (47.1%) daily, with the result that a daily saving of R 23 988.20 was experienced, reducing the payback period to 2.3 months (0.2 years). Through the installation of energy-efficiency technology and a suitable control philosophy, a cost-effective, energy-efficiency improvement was created on the case-study cooling plant. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014
33

A needs assessment of the market for resource efficiency and cleaner production services in the Vaal Triangle / Theunis Christoffel Botha

Botha, Theunis Christoffel January 2014 (has links)
Major energy-consuming countries implemented new laws on energy-efficiency during the course of 2013. The new energy-efficiency law make provision for a 16% reduction in energy intensity by 2015 in China. New law in the United States of America requires new fuel-economy standards. European Union law aims for a cut of 20% in energy demand for the countries forming part of the European Union. Japan, with the country's new energy strategy aims to decrease electricity demand with 10% by 2030 as stipulated in the new energy strategy. South Arica is currently experiencing a shortage in electricity generating capacity and operates within its reserve margin. The construction of new power stations is in process to address the shortage but Eskom must finance these assets by increasing the electricity tariff. Electricity prices are predicted to double from 2013 to 2017. In addition to the tariff increases, the Energy Conservation Scheme (ECS) is also planned by Eskom whereby all electricity consumers have to reduce their electricity consumption by 10% or face penalties. Energy efficiency initiatives in South Africa will help meet some of the country's social, economic, and environmental goals. These initiatives are important as they immediately tackle the problem of electricity shortages and are a cost-effective way of increasing available electricity supply. The aim of this study was to determine the need for businesses in the Vaal Triangle to be resource efficient and practice clean production in order to be able to capitalise on that need. With the current knowledge and technology available, Resource Efficiency and Cleaner Production (RECP) will prove to be a future necessity for industry. To determine the perceived readiness towards a green economy contribution is thus of importance. The study did a review on RECP, energy efficiency, supply of energy in South Africa, focus areas for energy efficiency and the benefits thereof. The study discussed energy efficiency incentive schemes and subsidisation funds available in South Africa. The study assessed the primary fields for RECP, the drivers and barriers to RECP and the willingness to participate in RECP initiatives in the Vaal Triangle. The study concluded that there exists a need in the Vaal Triangle for RECP initiatives and that there exists potential for the start of a green economy in the region. The research indicated the reaction towards RECP initiatives to be very positive in the studied region. / MBA, North-West University, Potchefstroom Campus, 2015
34

Development of a supervisory system for maintaining the performance of remote energy management systems / Johan Nicolaas du Plessis

Du Plessis, Johan Nicolaas January 2014 (has links)
Energy services companies (ESCOs) typically implement energy management systems (EMSs) as part of Demand-Side Management (DSM) projects on South African mines. After DSM project completion, the mine becomes responsible for maintaining the performance of the EMS. Due to a lack of experience in using specialised EMSs, mines typically contract ESCOs for EMS maintenance. However, maintaining a large number of EMSs remotely is a resource-intensive task because of time wasted on daily monitoring and travelling to perform on-site maintenance. For the same reason, remote maintenance technologies have become widely used to maintain cellular devices, vehicles and industrial equipment. Mine EMSs typically control production-critical systems that in turn ensure safe working conditions underground. EMSs execute highly specialised control philosophies to achieve electrical energy management, while ensuring safe and productive system operation. None of the work done on remote maintenance, however, provides an integrated solution to maintain the performance of a growing number of these specialised EMSs. As part of this study, a supervisory system was developed to optimise remote maintenance of different EMS technologies. The supervisory system builds on the fundamentals of existing remote maintenance technologies, complemented by comprehensive diagnostics of specialised EMS technologies. This is possible through automated diagnostics of EMS components, the control philosophy and overall EMS performance. Maintenance management forms part of the supervisory system to ensure that maintenance is performed with optimal efficiency. A system implementation was executed to prove the feasibility of the supervisory system. The functional operation of the system was verified with pre-set scenarios that simulated day-to-day operation and common fault diagnostic events. As part of the case studies conducted for this thesis, the supervisory system was integrated with three distinct EMS technologies implemented on South African mines. To support the results of these case studies, the system validation was extended through integrations with seven additional EMSs. For the first time, a supervisory assessed the condition of the EMS components, the control philosophy and DSM performance comprehensively. The results (obtained over a period of more than six months) indicated that the average operational availability of EMS components improved from 90% to 97%. The average EMS performance improved from 1.8 MW to 2.5 MW, an improvement of 39%. The resulting electricity cost reduction achieved on the case studies accumulated to approximately R6 million during the respective assessment periods. The supervisory system facilitated efficient EMS maintenance, thus reducing the risk of unsafe working conditions and production interruptions. The system also allowed maintenance personnel to improve the diagnostic process continually, thus aligning with the standards documented in ISO 50001:2011 (ISO, 2011) regarding continual improvement of electrical energy management initiatives. The new supervisory system is scalable, thus an ESCO can maintain the performance of a growing number of EMSs remotely. Results of this study support further supervisory system integration with compatible EMS technologies, and expansion to new EMS technologies. The modular design of the supervisory system provides a basis for the development of a cross-industry platform for maintaining EMS performance. / PhD (Computer and Electronic Engineering), North-West University, Potchefstroom Campus, 2014
35

Load management on a municipal water treatment plant / Lötter Adriaan Els

Els, Lötter Adriaan January 2015 (has links)
Water Treatment Plants (WTPs) supply potable water which is transferred by pumps to various end users. WTPs and other sub-systems are energy intensive with pump installed capacities varying between 75 kW – 6 000 kW. It has therefore become important to optimise the utilisation of WTPs. Cost savings can be achieved and the load on the national grid can be reduced. The aim of this study is to develop and implement load management strategies on a municipal WTP. In this investigation the high lift pumps are deemed to be the largest consumers of electricity. Strategies to safely implement load management on a WTP were researched. By optimising the operations of the pumps, significant cost savings can be achieved. Comparisons between different electricity tariff structures were done. It was found plausible to save R 990 000 annually, on a pumping station with four 1 000 kW pumps installed, when switching to a time-of-use dependent tariff structure. Strategies to optimise plant utilisation while attempting a load management study include the optimisation of filter washing methods and raw water operations. An increase of 34% in efficiency for a filter backwash cycle was achieved. To accommodate the effects of the load management on the WTP, the operation of valves that allow water to distribute within the plant was also optimised. The implemented control strategies aimed to accomplish the full utilisation of the WTP and sub-systems to achieve savings. An average evening peak period load shift impact of 2.21 MW was achieved. Due to filter modifications the plant is able to supply 5% more water daily. A conclusion is drawn regarding the success of the strategies implemented. Recommendations are made for further research. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2015
36

Development of a data consolidation platform for a web-based energy information system / Ignatius Michael Prinsloo

Prinsloo, Ignatius Michael January 2015 (has links)
Global energy constraints and economic conditions have placed large energy consumers under pressure to conserve resources. Several governments have acknowledged this and have employed policies to address energy shortages. In South Africa, the lacking electrical infrastructure caused severe electricity supply shortages during recent years. To alleviate the shortage, the government has revised numerous energy policies. Consumers stand to gain nancially if they embrace the opportunities o ered by the revised policies. Energy management systems provide a framework that ensures alignment with speci cations of the respective programs. Such a system requires a data consolidation platform to import and manage relevant data. A stored combination of consumption data, production data and nancial data can be used to extract information for numerous reporting applications. This study discusses the development of a data consolidation platform. The platform is used to collect and maintain energy related data. The platform is capable of consolidating a wide range of energy and production data into a single data set. The generic platform architecture o ers users the ability to manage a wide range of data from several sources. In order to generate reports, the platform was integrated with an existing software based energy management system. The integrated system provides a web-based interface that allows the generation and distribution of various reports. To do this the system accesses the consolidated data set. The developed energy information tool is used by an ESCo to gather and consolidate data from multiple client systems into a single repository. Speci c reports are generated by the integrated system and can be targeted at both consumers and governing bodies. The system complies with draft legislative guidelines and has been successfully implemented as a energy information tool in practice. / MIng (Computer and Electronic Engineering), North-West University, Potchefstroom Campus, 2015
37

Improving DSM project implementation and sustainability through ISO standards / Mariska van Heerden

Van Heerden, Mariska January 2014 (has links)
South African industries are challenged with above inflation electricity tariffs which may affect their competitiveness within their relative markets. In order to successfully manage these rising electricity costs and ensuing top market competition, a well organised demand side management (DSM) strategy must be implemented. Energy service companies (ESCos) have been assisting Eskom, South Africa’s leading electricity utility, in managing energy projects around the country. These DSM projects have introduced remarkable electricity and cost savings. However, the need for a sustainable energy management system (EnMS) within these projects does exist. This dissertation illustrates and discusses an EnMS designed to achieve maximum possible energy savings performances. The ISO 9 001 (quality management), ISO 14 001 (environmental management) and ISO 50 001 (energy management) standards were integrated for the development and implementation of this system. It provides a framework for project engineers and industrial clients to apply before, during and after project implementation. The use of the Plan-Do-Check-Act (PDCA) cycle will be applied throughout the dissertation. The PDCA cycle follows basic steps recommended by the relevant ISO standards. This cycle emphasises the concept of continual improvement. The developed EnMS was successfully implemented on various DSM projects. This selection includes previously maintained and new implemented projects. An analysis between the implementation and post- implementation performances supports the achieved results. The results of the case studies are presented in this dissertation. This dissertation illustrates that the continual improvement of an ISO based EnMS will result in a sustainable increase in electricity savings. An overall increase in project quality can be defined and measured according to the electricity consumptions and electricity cost savings. These electricity cost savings from the selected projects resulted to nearly R18 million during project implementation. A total amount of R52 million was already saved during the maintenance phase of 2014. This cost savings only reflect the results of the eight selected projects for the first eight months in 2014. The EnMS explained in this dissertation indicates that a continually controlled framework can improve the quality of DSM project implementation and sustainability. With the flexibility of changing the system according to impulsive constraints and client demands, the system can be used with various DSM projects. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2015
38

Development of a decision making model for the assessment of electricity demand side management in the State of Kuwait

Al-Ajmi, Abdullah A. January 2014 (has links)
Kuwait’s per capita electrical energy consumption is among the largest in the world, reaching 13,663 kWh per person in 2011. The electricity demand in Kuwait is increasing, which requires additional investments in power generation. A particular challenge in Kuwait is the peak demand in summer, when extreme heat increases air conditioning loads. Peak demand reached 11,220 MW in 2011, with a fast growth rate averaging 5.6% over the last decade and a maximum production capacity of around 14,720 MW. It is not possible to cope with this demand simply by increasing generation capacity. Therefore, the only alternative available to Kuwait is to control electricity demand via demand-side management. The main objective of this research is to assess and select the optimal demand- side management (DSM) technologies for buildings in the governmental sector (office, religious and school buildings) and to investigate the key factors in the evaluation process. To achieve the research objective, a model was proposed using multi-criteria decision-making techniques to enable the forecasting and comparison of DSM alternatives that are suitable for buildings. The developed model includes environmental, economic, technical and social considerations. The research methodology is based on three main phases. Phase 1: Data collection through a mail questionnaire that was sent to 42 experts for the identification of criteria and demand-side management alternatives. Phase 2: Screening and narrowing of the data collected in Phase 1 using a set of questionnaires, including the identification of potential DSM alternatives and criteria suitable for further analysis. This phase was performed through the Delphi process, taking into consideration the opinions of 28 experts. Phase 3: Use of Multi-criteria Decision Making (MCDM) techniques, namely the Analytic Hierarchy Process (AHP) and Fuzzy Analytic Hierarchy Process (FAHP), to evaluate and rank the identified DSM alternatives and criteria. This was done using pairwise comparisons of 17 experts to evaluate the criteria and alternatives for the buildings (office, religious and school). The research showed that the experts identified six alternative technologies and five criteria for the selection and evaluation of governmental buildings (office, religious and school). After performing the three phases of this research project, a set of criteria and alternatives were ranked based on the information gathered from every group of experts. It was found that reduction in consumption, capital cost and ease of implementation were the three most recommended criteria for the selection of DSM technologies in Kuwait government buildings while high efficiency lighting and programmable thermostats were identified as the most recommended DSM technologies for these buildings. An important aspect of this research is that unlike engineering approaches which sometimes depend on expensive test equipment or, often for building design, expensive computer modelling exercises, the proposed framework can be easily adopted by anyone without any significant financial cost. The FAHP approach was also tested and its results compared with those of AHP. There was a slight difference between using AHP and FAHP in terms of ranking the criteria and alternatives but that the difference barely affects the ranking. It was found that the AHP provides a convenient MCDM approach for solving the complex problem of selecting the optimal DSM options for buildings. The contributions of this thesis are the development of a novel framework for systematic selection and ranking of DSM technologies in different types of buildings using the Delphi method and AHP; the identification of the most important DSM technologies and criteria for their selection for three types of governmental buildings in Kuwait; and establishing that results from using AHP and FAHP for the selection of appropriate DSM measures in these buildings are almost identical, so use of AHP is likely to be sufficient in most building studies of this type.
39

Modernising underground compressed air DSM projects to reduce operating costs / Christiaan Johannes Roux Kriel

Kriel, Christiaan Johannes Roux January 2014 (has links)
Growing demand for electricity forces suppliers to expand their generation capacity. Financing these expansion programmes results in electricity cost increases above inflation rates. By reducing electricity consumption, additional supply capacity is created at lower costs than the building of conventional power stations. Therefore, there is strong justification to reduce electricity consumption on the supplier and consumer side. The mining and industrial sectors of South Africa consumed approximately 43% of the total electricity supplied by Eskom during 2012. Approximately 10% of this electricity was used to produce compressed air. By reducing the electricity consumption of compressed air systems, operating costs are reduced. In turn this reduces the strain on the South African electricity network. Previous energy saving projects on mine compressed air systems realised savings that were not always sustainable. Savings deteriorated due to, amongst others, rapid employee turnover, improper training, lack of maintenance and system changes. There is therefore a need to improve projects that have already been implemented on mine compressed air systems. The continuous improvement of equipment (such as improved control valves) and the availability of newer technologies can be used to improve existing energy saving strategies. This study provides a solution to reduce the electricity consumption and operating costs of a deep level mine compressed air system. This was achieved by modernising and improving an existing underground compressed air saving strategy. This improvement resulted in a power saving of 1.15 MW; a saving equivalent to an annual cost saving of R4.16 million. It was found that the improved underground compressed air DSM project realised significant additional electrical energy savings. This resulted in ample cost savings to justify the implementation of the project improvements. It is recommended that opportunities to improve existing electrical energy saving projects on surface compressed air systems are investigated. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014
40

Cost-Effectiveness of Electricity Energy Efficiency Programs: Demand-Side Management's (DSM) Future Role in Energy Markets and Feasibility of Smart Meters in New York City

Huang, Zhixing January 2011 (has links)
Thesis advisor: Scott Fulford / Can smart metering program and time-of-use (TOU) prices help reduce energy consumption in New York City? Being able to track electricity consumption levels and to modify consumer usage patterns are important for policy makers to efficiently manage the energy markets. Unfortunately, no reliable and up-to-date data have been brought to bear on this question. I study the effects of time-of-use (TOU) prices and smart metering for the residents of Shanghai and I investigate further what can policy makers do in order to adapt and transfer this successful DSM experience from Shanghai to the residential sector in New York City. The primary objective of my study is to characterize the realistic short-term and long-term potential for the smart metering program in New York City given my empirical findings that the smart metering program has had brought great benefits to the residents of Shanghai. People respond to incentives; if electricity is charged at different prices throughout a day, consumers are likely to shift their usage to when it is cheaper. My findings suggest that policy makers should think harder about designing a pricing scheme that can optimize the social plus. / Thesis (BA) — Boston College, 2011. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: College Honors Program. / Discipline: Economics Honors Program. / Discipline: Economics.

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