• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 119
  • 12
  • 8
  • 7
  • 6
  • 3
  • 3
  • 3
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 204
  • 204
  • 204
  • 119
  • 44
  • 40
  • 37
  • 36
  • 33
  • 31
  • 30
  • 29
  • 28
  • 28
  • 27
  • 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.
91

Improved implementation strategies to sustain energy saving measures on mine cooling systems / Philip Mare

Maré, Philip January 2015 (has links)
Reliable, efficient and cost-effective energy supply is crucial for economic and social development. Mining and industrial sectors consumed close to 37% of the total energy produced in the world during 2013. The South African power network is strained by the rapid expansion of mining, industrial and public sectors. Generation, transmission and distribution of electrical energy are in progress, but supply will not meet demand in the near future. The South African electricity supplier needs capital for expansion. Electricity price increases have been significantly higher than increases in the gold price over the last few years. Mining companies are under pressure from government to improve their labour relations. They are obligated to spend money on local infrastructure development. Therefore, cost efficiency receives higher priority than ever before and requires an implementation strategy. Cooling systems on mines proved to be significant electricity consumers. These systems lack integrated management and efficient and optimised control. Electricity demand can be reduced through implementation of energy saving measures on these cooling systems. Energy saving measures reduce the operational costs of mining to ensure that mines stay globally competitive. The identification of long-term challenges for energy saving measures is crucial. Successful implementation of energy saving measures results in improved utilisation and performance of mine cooling systems. These measures must be maintained to ensure a constant positive impact on reduced electrical energy consumption. The electrical energy savings are dependent on external factors, such as ambient conditions. Improved implementation strategies of energy saving measures will prevent deterioration of utilisation and performance of the mine cooling systems. Monitoring and reporting of key performance indicators are crucial. Lack of integrated maintenance can lead to lost opportunities and the deterioration of equipment and machines. The improved implementation strategies in two separate case studies proved sustainable savings of 1.73 MW and 0.66 MW respectively. The electricity cost savings for Mine A and Mine B are R8.8 million and R2.9 million respectively. These savings have been sustained for periods of seventeen and seven months respectively, indicating the value of the study. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2015
92

Potential of the implementation of demand-side management at the Theunissen-Brandfort pumps feeder

Motlohi, Khotsofalo Clement 2006 November 1900 (has links)
Thesis (M. Tech.) - Central University of Technology, Free State, 2006 / Demand-side management (DSM) is one of the integrated energy planning concepts that has only recently been introduced in South Africa. This concept needs to be fully developed in order to suit current industrial development situations. South Africa’s coal and water reserves will not last forever because of the growing population and the accompanying demands on our energy resources {[5] of Chapter 1]}. Therefore the demand-side interventions are considered on an effective means of overcoming these problems. The traditional approach of electrical energy utilisation by Eskom and its customers has to be reviewed. Socio-economic and environmental development benefits must also be reviewed. Advanced research on demand-side management has benefited the international world tremendously and this kind of research should also be done in South Africa. The research project for this study as described from chapter 1- 8 was undertaken to show the potential implementation of demand-side management and its interventions (DSM programme) on the Theunissen-Brandfort Pumps 11kV feeder (TBP). This would result in the generating of potential energy and cost-savings that would flow from the feasible DSM programme. This would be measured and verified by billing the actual saved energy at the TBP electrical system for the future. Every potentially saved-energy means one less potential reduction in emission. The case studies were conducted on Eskom’s entire TBP network and on four large power users which were identified and which provided the relevant potential results. Methodological design protocol processes for best-practice pollution prevention and the efficiency-energy (EE) audit protocol model, with its accompanying goal and objectives were used. The project concentrated on EE and time-of-use (TOU) factors related to the selected customers and the TBP as a whole, thus: potential Replacement and Rewinding of low efficiency with higher efficiency motors and the TBP feeder potential Load-Shifting. The stages within the EE, LS and DSM project process which were used for potential implementation are the following: project identification, energy audits and assumptions and recommendations for implementation. The M&V interaction with DSM, EE or LS project processes (methodology) for future implementation purposes (actual retrofitting) is also shown. The TBP feeder collective baseline (Figure 6.2) was quantified by trapezium rule. The feasible EE and LS programmes opportunities analysis on motors and the entire TBP were performed by inference and stipulation techniques and the potential energy reduction effects using a simulation programme called International Motor Selection and Savings Analysis (IMSSA). The potential LS programme was also performed based on the Eskom’s miniflex tariff defined time of use. TBP plant-wide EE and LS assessments conducted with the methodology mentioned, identified and quantified a total of two EE savings opportunities and were divided into four categories: those for short-term, long-term, none and best solution potential implementations (Table 7.9). As far as indirect results are concerned, DSM is a very new concept in South Africa and is consequently not well known. The study was based on simplicity in order to make the DSM subject very simple and easily accessible to future research. By using a simple and userfriendly IMSSA software programme, quick, relevant results were obtained. The study played an important role in influencing and educating interested parties about the importance of potential demand-side management concepts and objectives. The study compiled valuable information on EE, DSM (LS) and M&V that was previously unknown and, which will make future research much more accessible and manageable. It is recommended that all the motors identified as inefficient be rewound and replaced by new and efficient ones in the future. It is also very important that the potential LS programme be implemented only after these potential EE opportunities are implemented so that there will be sustainability and the DSM objectives may be achieved (Table 7.10). The project led to better grasp of electric energy consumption by the customers. From a socio-economic perspective, Eskom can distribute the surplus potentially saved energy of capacity at the TBP to other communities, which would also create employment if a new network could be built. Allocation of potentially saved energy to other population groups or customers of low-income groups in the Theunissen area would mean a significant lifestyle change. With regard to environmental benefits, previous research has proven that for every kWh of electricity saved, fewer emissions (e.g. C02) would be generated at the power station. The study addressed TBP-wide power use, focusing primarily on the demand-side interventions, but implications for improvements in the supply-side emission reductions were also considered.
93

The integrated effect of DSM on mine chilled water systems / Willem Schoeman

Schoeman, Willem January 2014 (has links)
The national electricity utility in South Africa, Eskom, is currently under pressure to supply the increasing demand for electricity on a national level. To address this problem in the short term, Eskom partially funds load management and energy efficiency projects. In the meantime, Eskom is also increasing their generation capacity through the erection of new power stations. To finance these capital projects, sharp tariff increases, higher than inflation, are levied, resulting in higher operating expenditures for the consumers. These increased tariffs are especially affecting industrial institutions. Large industries are therefore willing participants in the partially Eskom funded electricity savings programme that hold benefits for both parties. One of these large industries is the Mining Sector. This sector is an energy intensive group and consumes up to 15% of Eskom’s total output. The refrigeration and pumping systems used in the sectors are two of the major electricity consumers. As part of Eskom’s Demand Side Management (DSM) initiative, an electrical energy savings project was implemented in the deep mines’ chilled water systems. The cooling system is optimally controlled to ensure less underground water usage. This ensures that less water is pumped out by the dewatering system, reducing electrical energy usage. A variety of components, such as refrigeration and energy recovery depend on chilled water to function properly. Every relevant component was simulated and the verification of results was done through correlations with process data obtained from the mine. The simulation results showed acceptable error margins that would not influence accuracy. Two sites where a water supply optimisations project was implemented were selected as case studies. In both case studies, thermal results of the refrigeration and cooling system showed a reduction in cooling effectiveness. In case study A, the energy recovery components showed negative results. All of the results were converted to electrical energy costs to enable comparison. Constraints were evident during deep mine water supply optimisation. These were determined and the thermal effects were simulated. This study enabled basic quantifications of environmental impact and also determining project cost savings. The studies showed that positive and negative effects can be brought on in the mining systems with the reduction in chilled water use. In some cases the cooling system components showed a decrease in cooling effectiveness, but exhibited electrical energy savings. This impact was during periods where no personnel were underground in the working area. In conclusion the study also showed that cost savings resulting from the reduced chilled water are substantially higher than negative financial losses seen on the other components. / MIng (Electrical and Electronic Engineering), North-West University, Potchefstroom Campus, 2014
94

From Passive to Active Electric Distribution Networks

Campillo, Javier January 2016 (has links)
Large penetration of distributed generation from variable renewable energy sources, increased consumption flexibility on the demand side and the electrification of transportation pose great challenges to existing and future electric distribution networks. This thesis studies the roles of several actors involved in electric distribution systems through electricity consumption data analysis and simulation models. Results show that real-time electricity pricing adoption in the residential sector offers economic benefits for end consumers. This occurs even without the adoption of demand-side management strategies, while real-time pricing also brings new opportunities for increasing consumption flexibility. This flexibility will play a critical role in the electrification of transportation, where scheduled charging will be required to allow large penetration of EVs without compromising the network's reliability and to minimize upgrades on the existing grid. All these issues add significant complexity to the existing infrastructure and conventional passive components are no longer sufficient to guarantee safe and reliable network operation. Active distribution networks are therefore required, and consequently robust and flexible modelling and simulation computational tools are needed for their optimal design and control. The modelling approach presented in this thesis offers a viable solution by using an equation-based object-oriented language that allows developing open source network component models that can be shared and used unambiguously across different simulation environments.
95

Developing ESCO procedures for large telecommunication facilities using novel simulation techniques / Johann Francois van Rensburg

Van Rensburg, Johann Francois January 2006 (has links)
Peak electricity demand in South Africa will exceed the available operational generation capacity in 2007. The state utility Eskom is addressing this challenge, inter aha, with the implementation of the Demand-side Management (DSM) initiative. The aim of DSM is to defer the building of additional power stations by modifying the end-user pattern to reduce electrical load during the morning and evening peaks. At the end of 2005 the DSM programme has only achieved 30°/o of its target. Some of the biggest problems are the lack of knowledge on how to perform ESCO audits and availability of tools and procedures to enable Energy Service Companies (ESCOs) to evaluate DSM potential. Studies in South Africa have shown that 20°/o of the total municipal energy is utilised in commercial buildings. Additional investigations have shown that in the commercial sector approximately 50% of energy is used for air conditioning. Energy savings of around 30% can be realised through improved management procedures and retrofit projects of HVAC systems of existing buildings. Telecommunication companies own and operate a large portfolio of diverse buildings. It was shown that these buildings are very inefficient in terms of energy usage. Performing ESCO analyses on these building portfolios present huge savings opportunities for the building owners as well as load reduction opportunities to help meet DSM targets. ESCOs however face major problems in evaluating DSM projects on telecommunication facilities. Some of these problems are: time to perform the ESCO audits on such a large portfolio of buildings; skill levels of available personnel; lack of experience and structured audit process; availability of information; data capturing of information; determining the impact of the retrofits and calculating the savings and financial benefits of retrofits. Obtaining approval for DSM projects is also a lengthy process. Smaller ESCOs cannot afford to commit resources to ESCO investigations only to recover their investment after project approval. Having an ESCO procedure that will speed up the audit process will help the ESCO to minimise resources that need to be committed to these investigations. Having a tested and reliable ESCO procedure will also help Eskom since they will receive more and better quality DSM proposals. A new ESCO procedure for telecommunications facilities was developed. The primary requirements for the new ESCO procedure are that it should be simple, stable, fast and accurate. This procedure is evaluated against the known energy management opportunities in telecommunication facilities. Some of the benefits of the new ESCO procedure are: time taken to perform ESCO analysis on all types of buildings is drastically reduced; lower qualified personnel can be used to perform the ESCO analysis; any type of HVAC system configuration can be accommodated; new data capturing procedures ensure that only essential data is captured; integrated simulation software is used that can easy and accurately simulate the building operations and retrofits on a building; retrofit options suitable for telecommunication facilities are identified; contribution to the DSM programme is evaluated; financial evaluation of the retrofits and feasibility for DSM funding and results are integrated into a standardised reporting format. The new ESCO procedure was implemented on several case studies within the telecommunication infrastructure. Five different types of buildings were selected to implement the ESCO procedure. Each step of the procedure was evaluated and tested against the requirements of the new ESCO procedure. It was proven through implementation that the new ESCO procedure is successful in solving the unique problems in performing ESCO analyses for telecommunications facilities. Valuable insight into the problems that can occur during the ESCO process was highlighted, and recommendation for future work was presented. / Thesis (Ph.D. (Electrical Engineering))--North-West University, Potchefstroom Campus, 2006.
96

Erneuerbare Energien: Statistik der Energieflüsse

Tausche, Philipp 13 June 2017 (has links) (PDF)
This master thesis deals with the question how you could use “demand side management” to influence the consumer on the energy market. Because of the increasing part of the renewable energy the stability in the energy production will drop. With new technology the building of energy storages will be one way to deal with the problem. Another way is to influence the consumer. Firstly the thesis will give a brief overview about the current development of renewable energy. This includes the production time and location of every energy sources. After that the next chapter is about the consummation side of the energy market with the prices. A detailed examination will show the biggest groups of demander and their location and time of consumption. The third chapter will describes the German electricity market including the main problems with demand side management on this market: the low price elasticity. The last chapter will take in the actual demand side management. Methods and applications will show a possible way to overcome the main problem but can’t bring a universal solution. The reasons are the low amount of data referring to renewable energy and applied demand side management and the development of a new market with a less of fossil fuel. The new market would change all actual concepts of pricing and vice versa the consumption.
97

Modelamento da eficiência energética para o gerenciamento sustentável no setor industrial pela medição e verificação. / Energy efficiency modeling for the sustainable management through the measurement and verification.

Leite, Fábio Correa 09 April 2010 (has links)
O objetivo do trabalho é analisar os protocolos mais conhecidos de medição e verificação de programas de eficiência energética sob da ótica a aplicação do recurso privado em projetos de eficiência energética. A simples comparação de faturas de energia e a utilização não rigorosa de indicadores para determinação da energia economizada praticamente deixa de ser uma opção com a disponibilização de padrões compreensivos de M&V. Para tal são analisados estudos de caso de projetos de eficiência energética nos segmentos comercial e industrial e estes indicam um distanciamento entre as ferramentas modernas de M&V e a realidade, de modo que há dúvidas sobre garantia da sustentabilidade das ações ao longo do tempo. Dessa análise dos protocolos e estudos de caso foram identificadas demandas que são partes de uma metodologia proposta em 9 etapas focadas na sustentabilidade da energia economizada. A aplicação dessa metodologia é complementar à aplicação dos protocolos, tal que o engenheiro de eficiência energética possa pensar em todo processo de gestão e não apenas na implementação das MCEs. Esse trabalho conclui que a simples aderência aos protocolos de M&V é insuficiente para garantir a sustentabilidade das ações de conservação de energia a longo prazo. / The purpose of this work is to analyze the most well known Measurement and Verification protocols to energy efficiency programs under private capital owner perspective. The simple comparison between energy bills and the non-rigorous use of energy efficiency indicators in the energy savings calculation are not an option anymore with the introduction of comprehensive M&V protocols. With this aim, energy efficiency case studies are analyzed in the commercial and industrial sectors and indicated theres a gap between the modern M&V tools and the reality. Doubts around the sustainability of energy savings in the long term raised. Based on literature review, analysis of protocols and case studies, improvement opportunities were identified and are part of a 9 steps methodology focused on the sustainability of energy savings proposed in this work. This methodology works in cooperation with current M&V protocols. The EE engineer shall then be able to think in the overall management process and not only in the Energy Conservation Measure. This work concluded that the M&V tools adherence solely is insufficient to guarantee the sustainability of energy savings in the long term.
98

Modelamento da eficiência energética para o gerenciamento sustentável no setor industrial pela medição e verificação. / Energy efficiency modeling for the sustainable management through the measurement and verification.

Fábio Correa Leite 09 April 2010 (has links)
O objetivo do trabalho é analisar os protocolos mais conhecidos de medição e verificação de programas de eficiência energética sob da ótica a aplicação do recurso privado em projetos de eficiência energética. A simples comparação de faturas de energia e a utilização não rigorosa de indicadores para determinação da energia economizada praticamente deixa de ser uma opção com a disponibilização de padrões compreensivos de M&V. Para tal são analisados estudos de caso de projetos de eficiência energética nos segmentos comercial e industrial e estes indicam um distanciamento entre as ferramentas modernas de M&V e a realidade, de modo que há dúvidas sobre garantia da sustentabilidade das ações ao longo do tempo. Dessa análise dos protocolos e estudos de caso foram identificadas demandas que são partes de uma metodologia proposta em 9 etapas focadas na sustentabilidade da energia economizada. A aplicação dessa metodologia é complementar à aplicação dos protocolos, tal que o engenheiro de eficiência energética possa pensar em todo processo de gestão e não apenas na implementação das MCEs. Esse trabalho conclui que a simples aderência aos protocolos de M&V é insuficiente para garantir a sustentabilidade das ações de conservação de energia a longo prazo. / The purpose of this work is to analyze the most well known Measurement and Verification protocols to energy efficiency programs under private capital owner perspective. The simple comparison between energy bills and the non-rigorous use of energy efficiency indicators in the energy savings calculation are not an option anymore with the introduction of comprehensive M&V protocols. With this aim, energy efficiency case studies are analyzed in the commercial and industrial sectors and indicated theres a gap between the modern M&V tools and the reality. Doubts around the sustainability of energy savings in the long term raised. Based on literature review, analysis of protocols and case studies, improvement opportunities were identified and are part of a 9 steps methodology focused on the sustainability of energy savings proposed in this work. This methodology works in cooperation with current M&V protocols. The EE engineer shall then be able to think in the overall management process and not only in the Energy Conservation Measure. This work concluded that the M&V tools adherence solely is insufficient to guarantee the sustainability of energy savings in the long term.
99

Developing ESCO procedures for large telecommunication facilities using novel simulation techniques / J.F. van Rensburg

Van Rensburg, Johann Francois January 2006 (has links)
Thesis (Ph.D. (Electrical Engineering))--North-West University, Potchefstroom Campus, 2006.
100

Quantifying the benefits of greywater systems

Wickstead, Frank Anthony 05 April 2011 (has links)
This thesis offers a decision support framework to establish the economic feasibility associated with considering the installation of a greywater system. Because of the potential dangers and lack of widespread knowledge of greywater systems, the study begins by providing an explanation of current greywater technology to include the history of the technology, an explanation of greywater as opposed to reclaimed water, the potential risks of greywater use, and the necessary components of a greywater system. This decision support framework can be used with any scale of greywater system to be installed within any scale of facility. The example of an typical Atlanta, Georgia, USA multifamily rental development is used within the study to explain the framework by showing a working model. The need for water conservation in Georgia is shown and how greywater use dovetails with the need to lower overall usage. The legality of greywater use in Georgia along with the specific legal uses is also shown. The findings are then made State of Georgia and use specific to a multifamily development. The decision support framework provided is a viable tool. The sample framework in chapter 5 shows that the implementation of a greywater unit in the sampled facility would save 5,060,739.6 gallons of potable water per year with a 10.49 year payback cycle.

Page generated in 0.0827 seconds