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

Predicting electricity consumption and cost for South African mines / S.S. (Stephen) Cox.

Cox, Samuel Stephen January 2013 (has links)
Electricity costs in South Africa have risen steeply; there are a number of factors that have contributed to this increase. The increased costs have a considerable inuence on the mines and mining sector in general. It requires considerable planning to assist mines in such management. The present study addresses the development of a way to predict both electricity consumption and costs, which general involves a large range of personnel. The majority of planning personnel can be more usefully employed in other ways. The goal is not to replace such planners but make them more task e_ective. Automation, which will reduce their workload, may have little or no e_ect on performance. In some cases, however, automation may produce better results. There is a complex system to be analysed in the prediction of electricity consumption and costs. The existing prediction methodology is investigated in this study; the investigation highlights the need for a new methodology. The new method should be automated, easier to use and more accurate. Such a model is developed. The new prediction methodology extracts data from the monthly Eskom bills and stores it in a database. The data is grouped according to a new model and then normalised. An arti_cial neural network is used to \learn" the dynamics of the data to calculate new future electricity consumption. Electricity costs are predicted by multiplying the predicted electrical consumption with a calculated factor based on cost per electricity unit of the previous year with the expected increase added. The new methodology is integrated in a commercial energy management platform named Management Toolbox, which o_ers a range of functionality. In this study the prediction of electricity consumption and costs are implemented. The implementation is executed with simplicity in mind and care is taken to present the user with the optimal amount of data. The performance of the electricity consumption prediction is sensitive to production changes and the quality of the data history. Performance of the electricity costs prediction model is an improvement over the existing prediction method. The proposed methodology has greater accuracy and uses less personnel, which can lead to using most of the personnel on more important tasks. / Thesis (MIng (Computer and Electronic Engineering))--North-West University, Potchefstroom Campus, 2013.
22

Predicting electricity consumption and cost for South African mines / S.S. (Stephen) Cox.

Cox, Samuel Stephen January 2013 (has links)
Electricity costs in South Africa have risen steeply; there are a number of factors that have contributed to this increase. The increased costs have a considerable inuence on the mines and mining sector in general. It requires considerable planning to assist mines in such management. The present study addresses the development of a way to predict both electricity consumption and costs, which general involves a large range of personnel. The majority of planning personnel can be more usefully employed in other ways. The goal is not to replace such planners but make them more task e_ective. Automation, which will reduce their workload, may have little or no e_ect on performance. In some cases, however, automation may produce better results. There is a complex system to be analysed in the prediction of electricity consumption and costs. The existing prediction methodology is investigated in this study; the investigation highlights the need for a new methodology. The new method should be automated, easier to use and more accurate. Such a model is developed. The new prediction methodology extracts data from the monthly Eskom bills and stores it in a database. The data is grouped according to a new model and then normalised. An arti_cial neural network is used to \learn" the dynamics of the data to calculate new future electricity consumption. Electricity costs are predicted by multiplying the predicted electrical consumption with a calculated factor based on cost per electricity unit of the previous year with the expected increase added. The new methodology is integrated in a commercial energy management platform named Management Toolbox, which o_ers a range of functionality. In this study the prediction of electricity consumption and costs are implemented. The implementation is executed with simplicity in mind and care is taken to present the user with the optimal amount of data. The performance of the electricity consumption prediction is sensitive to production changes and the quality of the data history. Performance of the electricity costs prediction model is an improvement over the existing prediction method. The proposed methodology has greater accuracy and uses less personnel, which can lead to using most of the personnel on more important tasks. / Thesis (MIng (Computer and Electronic Engineering))--North-West University, Potchefstroom Campus, 2013.
23

Consumo de energia elétrica das exportações brasileiras por área de concessão de distribuição / Electricity consumption of Brazilian exports by distribution area

Maria Carolina Correia Marques 29 November 2012 (has links)
Este trabalho tem como objetivo analisar a composição setorial do consumo de energia elétrica incorporado às exportações brasileiras em cada área de concessão de distribuição. Para tanto, foi elaborada uma matriz de insumo-produto inter-regional e coeficientes setoriais de consumo de energia elétrica por área de concessão. Foi constatado que o consumo de energia elétrica incorporado às exportações é maior nos setores industriais e que a produção destinada à exportação é mais eletrointensiva que a produção destinada ao consumo interno em 37 das 58 áreas de concessão analisadas. / The objective of this dissertation is to analyze the sectorial composition of the electric energy consumption used in the production of exported goods and services in each electricity distribution concession area in Brazil. To accomplish this goal, an input-output matrix was elaborated, along with sectorial coefficients of electric energy intensity. The results indicate that the sector which consumes the most energy in their exports is the industrial sector. There was also an indication that Brazilian exports consume more electric energy throughout their productive structure than the production absorbed internally in 37 of the 58 electricity distribution concession areas.
24

Medidor de consumo de energia elétrica descentralizado e com interface WEB / Decentralized electrical power meter, with WEB interface

Moro, Jefferson Zortéa, 1983- 23 August 2018 (has links)
Orientador: Elnatan Chagas Ferreira / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-23T02:39:21Z (GMT). No. of bitstreams: 1 Moro_JeffersonZortea_M.pdf: 4211036 bytes, checksum: df7a8907629ae3a423fc16dbd9f4783e (MD5) Previous issue date: 2013 / Resumo: Nos últimos anos, grandes esforços vêm sendo feitos com a intenção de mostrar às pessoas o montante de energia gasto por cada eletrodoméstico, uma vez que essa informação leva consigo a principal base do programa de eficiência energética que pode ser feito pelos próprios usuários domésticos. Para ajudar o consumidor a monitorar seus gastos, foi desenvolvido um medidor de energia elétrica, capaz de informar o consumo de cada circuito que compõe a rede elétrica da residência, além de permitir a identificação em tempo real, do consumo de energia elétrica dos diversos equipamentos conectados nesses circuitos. Esse trabalho apresenta um simples e funcional método não intrusivo para se medir o consumo de energia elétrica, de tal forma que pode ser aplicado em programas de eficiência energética, sendo portando a interface que alimenta o consumidor com informações sobre os gastos das diversas cargas / Abstract: Currently a large effort are being done with the intention to educate people about how much energy each electrical appliance uses in their houses, since this knowledge is the fundamental basis of energy efficiency programs that can be managed by the household owners. To help the home consumer to monitor their electric power consumption, it was developed an electric power meter, in order to display the spending in each circuit, as well as the real time identification of all equipment plugged in each circuit. This paper presents a simple yet functional non-intrusive method for electric power measurement that can be applied in energy efficiency programs, in order to provide a better knowledge of the energy consumption of the appliances in a home / Mestrado / Eletrônica, Microeletrônica e Optoeletrônica / Mestre em Engenharia Elétrica
25

Apply heat pump systems in commercial household products to reduce environmental impact : How to halve the electricity consumption for a household dishwasher

Bengtsson, Peder January 2017 (has links)
In the household appliance industry, heat pump systems have been used for a long time in refrigerators and freezers to cool food, and the industry has driven the development of small, high-quality, low-price heat pump components. In the last few decades, heat pump systems have been introduced in other household appliances, with the express purpose of reducing electricity consumption. Heat pump tumble dryers have been on the market since 2000 and dominate the market today. A heat pump dishwasher was introduced on the market in 2014 and a heat pump washing machine in 2016. The purpose of adding a heat pump system in these three products was to decrease electricity consumption. Papers I and II used a methodology where transient simulation models were developed and used to increase knowledge about how to decrease electricity consumption for a tumble dryer and a dishwasher by adding a heat pump system. Papers II to V showed that a lower electricity consumption and lower global warming potential together with an energy-efficient drying method, where no humid air evacuates to the kitchen, give a heat pump dishwasher competitive advantages compared to any conventional dishwasher currently on the market. Using simulations, this dissertation concludes that a future commercial heat pump dishwasher, using R600a as a refrigerant, will reduce electricity consumption and total equivalent warming impact (TEWI) by 50% compared to the conventional dishwasher. The willingness from the customer chain to pay extra for this heat pump dishwasher is because of the decreases electricity consumption and the fact that no humid air evacuates to the kitchen. This willingness makes the heat pump dishwasher to a variant which have possibility to succeed on the future market. The challenge for the manufacturer is to develop and produce a high-quality heat pump dishwasher with low electricity consumption, predict future willingness to pay for it, and launch it on the market at the right moment with the right promotion in order to succeed. / The competition in the household appliances industry is strong. Manufacturers are continuously trying to develop, produce and sell product functions and features with good profit. To continually develop new features that the customer chain is willing to pay for is a key factor for a manufacturer to survive. In this study has a heat pump system been added as a new feature to a dishwasher. The first heat pump dishwasher was introduced on the market in 2014 and the heat pump system was only used to heat the dishwasher. Comparing that first heat pump dishwasher was a new closed drying method introduced in this study where no humid air evacuates to the kitchen. Experiments and simulations showed that a dishwasher with an added heat pump system can decrease the total electricity consumption by 50% when cleaning and drying the dishware comparing to an on market conventional dishwasher. The willingness from the customer chain to pay extra for this heat pump dishwasher is because of the decreases in electricity consumption and the fact that no humid air evacuates to the kitchen. This willingness makes the heat pump dishwasher to a variant which have possibility to succeed on the future market.
26

Posters as a passive intervention to reduce electricity and water consumption in the University of Pretoria's Groenkloof residences

Matsebula, Lindokuhle Benjamin January 2018 (has links)
Potable water is a relatively scarce natural resource. This scarcity is evident on a global scale. For humankind potable water is not only needed to sustain life, but also to engage in activities that maintain and enhance its own comfort and quality of life. These activities contribute to the degradation of water quality and exacerbating water scarcity. Electricity is a resource that needs to be generated, and is used significantly to also maintain and enhance human comfort, and quality of life. The generation of electricity produces a significant amount of greenhouse gases, gases that contribute to climate change. The use of both resources needs to be more ecologically sustainable to reduce the negative impact caused. Wherever possible, the use of these resources should be reduced. University residences utilise substantial amounts of water and electricity. This is because they are commonly designed to accommodate a large number of students. Implementing a behaviour change intervention in a residence therefore has the potential for greater ecological impact if the intervention is successful, due to the large number of people. There are different types of interventions aimed at changing behaviour, with some being active and others passive. Being active or passive is determined by whether or not direct interaction with the subject is required to achieve the desired change. Information provision can be a passive intervention by using posters and pamplets. It can also be active by using Q&A sessions and lectures. The study aimed to determine if the use of a passive behaviour change intervention could result in the reduction of water and electricity consumption in university residences. The passive intervention utilised was prompting in the form of posters. A quasi-experimental design with a mixed methods approach was employed. Quantitative data were meter readings for both electricity and water, while quantitative data were obtained from focus groups. 3 female residences at the University of Pretoria's Groenkloof campus were used in this study. Posters were placed at the points of decision in two of the residences. The third female residence was monitored as the control and no posters were put up in it. Monthly water and electricity meter readings were used to determine if this change had occurred. Focus groups were conducted to understand from the subjects how the intervention had affected them, if at all. Results from this study indicated that water and electricity consumption was reduced, with some reductions being statistically significant and others not. The study, however, cannot confidently predict that the intervention was successful due to various limitations. / Dissertation (MSc)--University of Pretoria, 2018. / Construction Economics / MSc / Unrestricted
27

Empirical modeling of the thermal systems in an apartment : A study of the relationship between household electricity consumption and indoor temperature

Wallentinsson, Måns, Jacob, Rutfors January 2020 (has links)
In this study, linear and non-linear models were trained on real data to mimic the relationship between household electricity consumption and indoor temperature, in the rooms of an apartment in downtown Stockholm. The aim was to better understand this relationship and to distinguish any divergence between the different rooms. With data from two weeks of measurements, the models proved to perform well when tested on validation data for almost all rooms, only showing performance dips for the middle room. A noticeable correlation between the electricity consumption and the indoor temperature was observed for all rooms except the bedroom. However, the benefits of using this information to predict the indoor temperature are limited and differ between the rooms. The household electricity consumption primarily brought beneficial information to the kitchen models, where most of the heat generating appliances were located. It was found that linear models were sufficient to represent the thermal systems of the rooms, performing equally well and often better than non-linear models.
28

The Role of Comparative Electricity Use Feedback at the Building Level in University Research Buildings

Ma, Daghoo 03 June 2013 (has links)
University research buildings are significant energy consumers in the United States. There is therefore a need to reduce energy use on the nation's campuses, not only cutting their carbon footprints but also saving money. Universities' efforts to reduce energy use include updating older facilities, implementing renewable energy systems, and encouraging energy saving behavior. This study evaluated the differential effects of two forms of feedback on electricity consumption in two groups of research buildings on a college campus to determine whether providing feedback to energy users has an impact on energy conservation behavior. A control group of buildings received no feedback regarding their electricity use. In the first study group of buildings, occupants received information about their electricity consumption with some electricity saving tips, distributed via email. The same procedure was followed with building occupants in the second study group, who received additional information showing their electricity consumption performance in comparison to other buildings within the study group. The baseline reading was conducted a week before the experiment began in August, 2012. Over the course of the five week study, the daily adjusted average reductions in electricity usage compared to the control group were less than 1 percent for both study groups, with study group 1 achieving an average reduction of 0.2 percent and study group 2 an average reduction of 0.8 percent. Although the reduction observed for study group 2 was 4 times greater than that for study group 1, the saving was not continuous over the study period. Accordingly, the result was deemed to be not statistically significant and the effectiveness of comparative energy use feedback in university research buildings was not supported. However, even small savings in the energy used in university research buildings can be very important in terms of the total amount of energy saved because research buildings use significantly more energy than other buildings on campus such as academic buildings and residence blocks. This study concludes with a consideration of potentially fruitful directions for future research into developing new ways to reduce the energy consumption on university campuses. / Master of Science
29

Managing Water and Electricity Consumption in University Residence Halls: a Study on Promoting Voluntary Resource Conservation by College Students

Parece, Tammy Erlene 27 May 2010 (has links)
With the world's population growing at a rate faster than the rate at which natural resources are being replenished, the challenge for governments and the world's citizens is how to conserve resources in order to provide a sustainable level of natural resources for the future. Conserving natural resources includes educating the citizens of the world on the connection between natural resource depletion and their levels of consumption of resources, such as energy and water. To help alleviate the increasing burden the world's growing population is placing on natural resources, sustainability should be a part of college students' education in their field of study and in preparing them to become good citizens. This education should take place in the classroom and other activities, including athletics, community organizations, and in their residence life. Teaching students living in on-campus residence halls conservation activities provides information that students can use in their private lives when setting up their own households. On-campus residence halls also provide an opportunity to evaluate any gender differences related to conservation activities since the demographics of the residence halls vary from all-female, to co-ed, to all-male students. Virginia Polytechnic Institute and State University (Virginia Tech) was the location for a study on promoting environmentally-relevant behavior (ERB) among students residing in on-campus residence halls. The objective of this study was to investigate the relationship between the use of educational strategies and natural resource consumption by promoting ERB among students living in the residence halls during the spring and fall semesters of the 2009 calendar year. Using the literature on promoting ERB, five different strategies were designed for promoting water and electricity conservation. Each strategy involved different stimuli to promote student participation in ERB. The information provided the students included reasons why ERB was important and specific actions to take to conserve resources. In three of the strategies, students were provided the results of their conservation efforts monthly during the study period. The Virginia Tech Office of Residence Life provided detailed information for the 49 on-campus residence halls, including buildings' characteristics such as heating and cooling methods, age, construction, renovation history, square footage, if the buildings contained offices or classrooms, and student population figures. Variability among the buildings was eliminated by comparing these differences, and then a random numbers table was used to assign each of the buildings to one of the five different groups. The strategy for each group was applied to four residence halls -- two dormitories and two Greek Houses, for a total of twenty buildings. In each strategy more stimuli were applied in an effort to produce higher consumption reductions. The Virginia Tech Office of Facilities provided four-years historical electricity and seven-years historical water usage, and provided monthly usage for each building during the study period. Electricity consumption reduction was promoted in all twenty halls but water consumption reduction was promoted only in the dormitories, as the University was unable to track water consumption for any one individual Greek House. The historical data showed that water usage per student was higher in most of the female-occupied dormitories, but no statistical difference was seen with regards to historical electricity usage and gender. Percent change in per student usage — kilowatt hours for electricity and gallons for water — was the calculation used to determine change in ERB. The results of this research showed a general relationship between educational strategies and natural resource consumption reduction over both study periods. However, except for the Greek-House Spring semester results, no statistical significant difference was found between any of the different study groups. Electricity reductions were achieved in seventeen of twenty residence halls during the first semester and in all but one residence hall during the second semester. Water reductions were achieved in five of ten dormitories during the first semester and in six of nine dormitories in the second semester. However, the use of more strategies did not lead to a higher percentage of reductions. During the first semester, a statistically significant difference was found in water usage and gender and the difference did not support a female predisposition for ERB. Decreases were achieved in excess of 10% in the male-occupied dormitories, but only a minimal reduction or increases were achieved in any of the dormitories that included female residents. After the first month of the second semester, similar results were seen relative to gender, so additional posters and prompts were placed in the female-occupied dormitories. As a result, water reductions were achieved in six dormitories with only small increases in the other three, and the semester final results did not show a statistical significant difference between genders. The lack of statistical difference between the study groups could be a result of contamination, the active environmental organizations on campus, or an observational effect. The study was contaminated within the first two weeks of the study period when all residence halls across campus learned of the research and requested their inclusion in the study. Since, the residence halls in the control groups were advised of their inclusion in the study, the students may have demonstrated ERB because of the knowledge they were being observed. A survey sent to the students living in the study residence halls revealed that 94.6% of the students had knowledge of the study, and that 77% participated in ERB. Students showed a propensity for ERB when they were informed on their consumptive behaviors' effects on natural resource depletion, and by being provided with actions they could take to change their behaviors. This research did not show that adding strategies of feedback and group leaders to information increased the percentage of consumption reductions in college students residing on Virginia Tech's campus. / Master of Science
30

Connectedness to Nature and Electricity Consumption: An Interdisciplinary Study of Behavior and Emotional Response to Nature in the Union Street Housing Complex

Trostle, Jenna January 2008 (has links)
No description available.

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