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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.
1

Efficient monitoring of mine compressed air savings / by P. Goosen.

Goosen, Pieter January 2013 (has links)
In 2011 South Africa's main electricity supplier, Eskom, experienced a peak electricity demand of 89% of their total installed generation capacity. The high utilisation rate makes it difficult to perform essential maintenance on the system. Eskom implements Demand-Side Management (DSM) projects in various industries, in order to reduce the demand and to ensure sustainable electricity supply. The mining sector consumes 14.5% of the total amount of electricity generated by Eskom. Mine compressed air systems can consume as much as 40% of a mine's total electricity requirements. This makes mine compressed air systems an ideal target for DSM. Electricity load seems to be reduced, but many DSM savings are not sustained throughout the project lifetime. An existing project feedback method of a specific Energy Services Company (ESCo) includes the manual collection of data from the mines and manual generation of reports. These reports show energy savings of the DSM projects to help the ESCo and their clients to improve and sustain the performance of the projects. A great amount of man-hours is used which results in large time delays in the feedback-loop. In order to address this, the need for a new automatic feedback reporting system was identified. This study mainly focusses on the development and implementation of a new method to monitor DSM savings on mine compressed air systems. It includes the reliable collection of data from mines, processing and storing of the data in a central database and generating savings reports. This is done automatically on a daily basis. In order to complete the feedback-loop, the reports are verified and emailed to clients and ESCo personnel on a daily basis. The new reporting system is implemented at a number of mines. Four of these project implementations are used as case studies to measure and interpret the effectiveness and value of this system. It saves a significant amount of man-hours and proves to be of great value in the sustainability of DSM project savings. Both Eskom and mining companies benefit from the efficient monitoring of mine compressed air savings. / Thesis (MIng (Computer and Electronic Engineering))--North-West University, Potchefstroom Campus, 2013.
2

Potential savings when re-instating mine DSM projects / Ian Mulder.

Mulder, Ian January 2012 (has links)
The increasing electricity demand in South Africa has lead to a shortage in electricity supply. In response to this problem Eskom has introduced multiple capacity expansion programs. Unfortunately the electricity shortage is expected to continue until Eskom’s capacity expansion programs are completed. Demand Side Management (DSM) is widely accepted as an immediate solution to the high electricity demand of South Africa. Numerous DSM projects implemented by ESCo’s have been successful, but over the years have not been sustainable. Without regular maintenance from the relevant ESCo, many projects have failed to achieve sustainable savings. After the implementation of DSM projects, all installed equipment and software becomes the property of the client. Experience has illustrated that some mines did not always have the expertise or available resources to monitor and maintain the projects. As a result the electrical energy savings of the project would gradually deteriorate. A feasibility study was conducted to determine whether the re-instatement of redundant and debilitated mine DSM projects could be marketed as the “low hanging fruit” of the industry. A key driver for this study, was the fact that costs involved for re-instatement of such DSM projects are generally considerably lower than those of new projects, yet still producing lucrative electricity savings. Three major mining entities discussed in this dissertation have neglected to realise a collaborative cost saving of R 55,5 Million per annum. This loss of opportunity can mainly be attributed to a lack of maintenance and monitoring of operational DSM projects on their mining sites. Three DSM projects related to the water reticulation system of the mine were investigated. It was discerned in all three cases that the successful re-instatement of DSM projects are indeed possible, but only when subjected to continuous monitoring. The maintenance performed on two of the three projects, respectively realised approximately R2,7 Million and R 750 000. This was achieved through the process of load shifting, over a period of one year. Maintenance on the third project realised approximately R1,5 Million through energy efficiency over a three month period. This dissertation illustrates that attractive savings in electricity and cost can be realised when re-instating redundant DSM projects in the mining industry. It also demonstrates the cost and time effectiveness of implementing such projects, compared to the focus on new DSM installations. / Thesis (MIng (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2013.
3

Efficient monitoring of mine compressed air savings / by P. Goosen.

Goosen, Pieter January 2013 (has links)
In 2011 South Africa's main electricity supplier, Eskom, experienced a peak electricity demand of 89% of their total installed generation capacity. The high utilisation rate makes it difficult to perform essential maintenance on the system. Eskom implements Demand-Side Management (DSM) projects in various industries, in order to reduce the demand and to ensure sustainable electricity supply. The mining sector consumes 14.5% of the total amount of electricity generated by Eskom. Mine compressed air systems can consume as much as 40% of a mine's total electricity requirements. This makes mine compressed air systems an ideal target for DSM. Electricity load seems to be reduced, but many DSM savings are not sustained throughout the project lifetime. An existing project feedback method of a specific Energy Services Company (ESCo) includes the manual collection of data from the mines and manual generation of reports. These reports show energy savings of the DSM projects to help the ESCo and their clients to improve and sustain the performance of the projects. A great amount of man-hours is used which results in large time delays in the feedback-loop. In order to address this, the need for a new automatic feedback reporting system was identified. This study mainly focusses on the development and implementation of a new method to monitor DSM savings on mine compressed air systems. It includes the reliable collection of data from mines, processing and storing of the data in a central database and generating savings reports. This is done automatically on a daily basis. In order to complete the feedback-loop, the reports are verified and emailed to clients and ESCo personnel on a daily basis. The new reporting system is implemented at a number of mines. Four of these project implementations are used as case studies to measure and interpret the effectiveness and value of this system. It saves a significant amount of man-hours and proves to be of great value in the sustainability of DSM project savings. Both Eskom and mining companies benefit from the efficient monitoring of mine compressed air savings. / Thesis (MIng (Computer and Electronic Engineering))--North-West University, Potchefstroom Campus, 2013.
4

Potential savings when re-instating mine DSM projects / Ian Mulder.

Mulder, Ian January 2012 (has links)
The increasing electricity demand in South Africa has lead to a shortage in electricity supply. In response to this problem Eskom has introduced multiple capacity expansion programs. Unfortunately the electricity shortage is expected to continue until Eskom’s capacity expansion programs are completed. Demand Side Management (DSM) is widely accepted as an immediate solution to the high electricity demand of South Africa. Numerous DSM projects implemented by ESCo’s have been successful, but over the years have not been sustainable. Without regular maintenance from the relevant ESCo, many projects have failed to achieve sustainable savings. After the implementation of DSM projects, all installed equipment and software becomes the property of the client. Experience has illustrated that some mines did not always have the expertise or available resources to monitor and maintain the projects. As a result the electrical energy savings of the project would gradually deteriorate. A feasibility study was conducted to determine whether the re-instatement of redundant and debilitated mine DSM projects could be marketed as the “low hanging fruit” of the industry. A key driver for this study, was the fact that costs involved for re-instatement of such DSM projects are generally considerably lower than those of new projects, yet still producing lucrative electricity savings. Three major mining entities discussed in this dissertation have neglected to realise a collaborative cost saving of R 55,5 Million per annum. This loss of opportunity can mainly be attributed to a lack of maintenance and monitoring of operational DSM projects on their mining sites. Three DSM projects related to the water reticulation system of the mine were investigated. It was discerned in all three cases that the successful re-instatement of DSM projects are indeed possible, but only when subjected to continuous monitoring. The maintenance performed on two of the three projects, respectively realised approximately R2,7 Million and R 750 000. This was achieved through the process of load shifting, over a period of one year. Maintenance on the third project realised approximately R1,5 Million through energy efficiency over a three month period. This dissertation illustrates that attractive savings in electricity and cost can be realised when re-instating redundant DSM projects in the mining industry. It also demonstrates the cost and time effectiveness of implementing such projects, compared to the focus on new DSM installations. / Thesis (MIng (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2013.
5

Combined solar and pellet heating systems for single-family houses : how to achieve decreased electricity usage, increased system efficiency and increased solar gains

Persson, Tomas January 2006 (has links)
In Sweden, there are about 0.5 million single-family houses that are heated by electricity alone, and rising electricity costs force the conversion to other heating sources such as heat pumps and wood pellet heating systems. Pellet heating systems for single-family houses are currently a strongly growing market. Future lack of wood fuels is possible even in Sweden, and combining wood pellet heating with solar heating will help to save the bio-fuel resources. The objectives of this thesis are to investigate how the electrically heated single-family houses can be converted to pellet and solar heating systems, and how the annual efficiency and solar gains can be increased in such systems. The possible reduction of CO-emissions by combining pellet heating with solar heating has also been investigated. Systems with pellet stoves (both with and without a water jacket), pellet boilers and solar heating have been simulated. Different system concepts have been compared in order to investigate the most promising solutions. Modifications in system design and control strategies have been carried out in order to increase the system efficiency and the solar gains. Possibilities for increasing the solar gains have been limited to investigation of DHW-units for hot water production and the use of hot water for heating of dishwashers and washing machines via a heat exchanger instead of electricity (heat-fed appliances). Computer models of pellet stoves, boilers, DHW-units and heat-fed appliances have been developed and the parameters for the models have been identified from measurements on real components. The conformity between the models and the measurements has been checked. The systems with wood pellet stoves have been simulated in three different multi-zone buildings, simulated in detail with heat distribution through door openings between the zones. For the other simulations, either a single-zone house model or a load file has been used. Simulations were carried out for Stockholm, Sweden, but for the simulations with heat-fed machines also for Miami, USA. The foremost result of this thesis is the increased understanding of the dynamic operation of combined pellet and solar heating systems for single-family houses. The results show that electricity savings and annual system efficiency is strongly affected by the system design and the control strategy. Large reductions in pellet consumption are possible by combining pellet boilers with solar heating (a reduction larger than the solar gains if the system is properly designed). In addition, large reductions in carbon monoxide emissions are possible. To achieve these reductions it is required that the hot water production and the connection of the radiator circuit is moved to a well insulated, solar heated buffer store so that the boiler can be turned off during the periods when the solar collectors cover the heating demand. The amount of electricity replaced using systems with pellet stoves is very dependant on the house plan, the system design, if internal doors are open or closed and the comfort requirements. Proper system design and control strategies are crucial to obtain high electricity savings and high comfort with pellet stove systems. The investigated technologies for increasing the solar gains (DHW-units and heat-fed appliances) significantly increase the solar gains, but for the heat-fed appliances the market introduction is difficult due to the limited financial savings and the need for a new heat distribution system. The applications closest to market introduction could be for communal laundries and for use in sunny climates where the dominating part of the heat can be covered by solar heating. The DHW-unit is economical but competes with the internal finned-tube heat exchanger which is the totally dominating technology for hot water preparation in solar combisystems for single-family houses. / <p>QC 20100916</p>
6

Šetří letní čas energii? Důkaz z České republiky / Does Daylight Saving Time Save Energy? Evidence from the Czech Republic

Častorálová, Lucie January 2019 (has links)
A b s tra c t The recent discussion of the European Parliam ent, member states, and citizens triggered the question whether there is s till a need for bi-annual clock shifting from the perspective of energy savings. Employing the difference-in-differences method on hourly data on electricity consumption between 2006 and 2017, the study con­ cludes th a t daylight saving tim e policy reduces aggregate electricity consumption by 0.35 % in the Czech Republic. Moreover, daylight saving tim e leads to 1% savings on domestic residential electricity consumption. Overall, daylight saving tim e increases electricity consumption in the morning, bu t decreases electricity consumption in the evening by greater amount. We have estimated th a t more than 65 % of to ta l electricity savings attributable to daylight saving tim e arose from effect of the daylight saving tim e on residential electricity consumption. 1
7

Behavioral demand response : A technology to support the smart grids of the future / Beteendebaserad efterfrågeflexibilitet : Ett sätt att stödja framtidens smarta elnät

Siddiqui, Usama Shahid January 2020 (has links)
Residential buildings are one of the main stakeholders to electricity consumption. As there is fast-paced technological advancement in electricity conservation, the residential buildings infrastructure has become very electricity-efficient in Sweden. However, there is still room for improvement with regards to electricity conservation via behavioral change. Meaning, residents have the potential to reduce household electricity consumption by developing a conservative behavior. The road to such a behavioral development is not straightforward. According to literature, behavioral change is influenced by different beliefs and norms. There also exists a global trend that fewer and fewer people are able to name a single neighbor, and it is aptly called “Globally Connected yet Locally Isolated”. In this master thesis the strategy to achieve electricity conservation is based upon local social cohesion, and the awareness of electricity, at Malvinas – a student residence at the campus of KTH Royal Institute of Technology. The study is carried out at LocalLife – a local social networking service for sustainable communities – implementing a mixed methodology of surveys and interviews. 8 LocalLife users are studied in detail. The result incorporates the most suitable features from the relevant topics that could enable long term change and retainment of users. The results showed that the participants: 1) indicated an increased energy awareness; 2) reported an improvement in local community-life; 3) felt motivated to change behavior to facilitate saving electricity. / I detta examensarbete görs en omfattande analys med hjälp av kvalitativa och kvantitativa metoder för att undersöka ifall användandet av LocalLife – en lokal social nätverkstjänst som pilot-testas vid Kungliga Tekniska Högskolan – har förbättrat användarnas beteende och attityder kring hushållselsförbrukning samt hjälpt till att förbättra det lokala samhällslivet. Bostadshus ger upphov till en betydande del av världens energiförbrukning. På grund av den snabba tekniska utvecklingen har byggnaderna blivit mycket mer energieffektiva i Sverige på senare tid. Det finns dock fortfarande förbättringspotential när det gäller att spara el genom att ändra de boendes konsumtionsbeteende. Att få till en sådan beteendeförändring är dock inte enkelt. Enligt litteraturen påverkas beteendet av uppfattningar och normer. Det finns dessutom en global trend där allt färre människor lär känna sina grannar, kallad “globalt uppkopplad men lokalt isolerad”. Denna uppsats studerar därför en strategi att spara el som går ut på lokal sammanhållning och ökad kunskap om elanvändning hos de boende i studentlägenheterna på Malvinas väg på KTH campus. Studien utförs bland användare av LocalLife, ett lokalt socialt nätverk för hållbara stadsdelar – genom att blanda metoder såsom enkäter och intervjuer. Åtta LocalLife- användare studeras i detalj. Resultatet presenterar de mest lämpliga delarna från de relevanta ämnena som kan möjliggöra en bestående beteendeförändring öka chansen för att behålla användarna. Resultaten visar att deltagarna: 1) visade på en ökad energimedvetenhet; 2) upplevde en förbättring av det lokala samhällslivet; 3) kände sig motiverade att ändra sitt beteende för att spara el.
8

Effective Thermal Resistance of Commercial Buildings Using Data Analysis of Whole-Building Electricity Data

Wang, Tian 04 June 2020 (has links)
No description available.
9

La valeur pour le consommateur d'une pratique de maîtrise de consommation : le cas de l'électricité / The value, for the consumer, of a practice of controlling consumption : the case of electricity

Innocent, Morgane 06 December 2017 (has links)
La thèse a pour objet de comprendre le sens que le consommateur donne à ses actes quand il pratique la maîtrise de sa consommation électrique (MCE), au sein de son foyer. La valeur produite par les différentes activités relevant de la MCE, comme, par exemple, éteindre les appareils en veille, constitue un reflet du sens que le consommateur attribue à cette pratique. Nous nous sommes, dans un premier temps, interrogés sur la nature des sources de valorisation et de dévalorisation qui émergent de la MCE. Nous avons identifié vingt-cinq sources qui sont autant d’appréciations ou de dépréciations de la MCE pour le consommateur. Nous avons ensuite cherché à déterminer comment ces sources sont structurées et nous avons pu déterminer que, dans l’esprit du consommateur, la valeur de la MCE se caractérise selon sept composantes. Quatre sont des composantes de valorisation (environnementale et citoyenne, de gestion du foyer, du bien-être eudémonique et des bénéfices secondaires) et trois sont des composantes de dévalorisation (expérientielle, sociale et associée au manque de connaissance). Nous avons ensuite cherché à comprendre comment la valeur de la MCE émerge de la pratique et quel peut être le rôle des différentes composantes (de valorisation et de dévalorisation) dans la formation de la valeur pour le consommateur et dans la conduite de son action. Nous avons pu confirmer que plus un individu réalise des gestes de MCE, plus il apprécie cette pratique via les composantes de valorisation et moins il la déprécie via les composantes de dévalorisation. Nous avons aussi constaté que le sens de la pratique évolue et s’enrichit quand elle s’intensifie. Deux leviers principaux se distinguent : la valorisation de la MCE au travers de ses conséquences sur la gestion du foyer et le bien-être de type eudémonique qui est retiré de cette pratique par l’individu. Le premier possède une influence très forte sur l’évaluation de la MCE par les consommateurs, et le second, dès lors qu’un individu pratique réellement la MCE, conduit les individus à poursuivre dans cette voie. / This thesis aims to understand the meaning that the consumer ascribes to his acts when one practises electricity consumption control (ECC) inside the dwelling. The value perceived by consumers associated with the various ECC’s activities, as, for example, to switch off devices in sleep mode, constitute a reflection of the meaning the consumer confers to this practice.We wondered, at first, about the nature of the sources of valuation and depreciation which emerge from the ECC. We identified twenty five sources which are so many appreciations or depreciations of the ECC for the consumer. Then, we tried to determine how these sources are structured and we were able to determine that, for consumers, the value of the ECC is characterized by seven components. Four of them are components of appreciation (environmental and citizen, of household management, the eudemonistic well-being and secondary profits). The three other are components of depreciation (experiential, social and associated with a lack of knowledge).Subsequently, we tried to understand how the value of the ECC emerges from the practice itself. We, also, wondered about the role of the various components (of appreciation and depreciation) in the ECC valuation for the consumer and in the conduct of action. We were able to confirm that the more an individual realizes ECC’s gestures, the more he appreciates this practice via the components of appreciation and the less he depreciates it via the components of depreciation. We also noticed that the meaning of the practice evolves and expands when practice becomes intensified. Two main levers set apart: the appreciation of ECC through its consequences on the household management and the eudemonistic wellbeing which is removed from this practice by the individual. The first one has a very strong influence on the evaluation of ECC by the consumers, and the second, once an individual really practises ECC, drives him to continue along this path.
10

Autonomní dům aneb život grid-off / The Autonomous House or Living Grid-off

Chlebný, Radek January 2013 (has links)
This thesis deals with energy self-sufficiency focusing on the independence of the electric grid. Basic line emanating project form a concrete proposal for autonomous energy supply system. Emphasis is placed primarily on photovoltaic systems, electric energy accumulation and selection of individual components of such a system. Another important part of the thesis is also an economic evaluation of design variations. The thesis also deals with a market research, and thereof derived benefit assessment of each technology. The accompanying chapters are then devoted to the history of autonomous life style or classification of buildings according to their energy performance.

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