Thesis (MPhil)--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: South Africa is facing an energy crisis on two levels; the existing capacity to supply electricity is unable to support future growth in demand, and the electricity being produced comes mostly from coal-fired power stations with associated emission problems. The South African government has a target for renewable energy to service 23% of the country’s energy consumption by 2013. This could potentially be realised through achievement of another government target, the installation of one million Solar Water Heaters (SWHs). On a technical level, Solar Water Heaters (SWHs) represent a completely viable renewable energy alternative for South Africa. It is an established and proven technology which has the potential to have a big impact on the country’s electricity capacity problems. SWHs can be used in a variety of applications from industry to households. Most of the hot water in South African homes is heated by electric resistance heating in standard electric water heaters and there are no technical obstacles to replacing most of these with SWHs, thereby delivering a saving of up to 70% of the water heating energy bill. Water heating currently accounts for 40% of domestic electricity consumption within a residential sector that uses 20-30% of the national supply. At the macroscale, the roll out of SWH programmes is completely scalable. The benefits of SWH installation accrue to the consumer in the form of a financial saving in the long-term and to society in the form of reduced emissions. Awareness of the benefits is growing amongst the general public, commercial institutions and in government. Sales are starting to pick up due to, amongst other reasons, electricity price hikes and government subsidies for SWH installations offered through the national electricity supply company, Eskom. A national building regulation enforcing energy-efficient water heating in new buildings has been drafted and is expected to be in place by mid 2011. The rate of change from electric to solar water heaters remains disappointingly slow, however. The SWH industry in South Africa accounts for less than 10% of total hot water solutions sold. This study sought to establish the opportunities as well as possible barriers for the creation of SWH programmes within the insurance sector. Close to 50% of all standard electric water heaters installed in South Africa are procured and installed via the insurance industry due to the failure of units that have endured beyond the manufacturer’s guarantee period. This presents an opportunity for interventions that encourage policyholders to change to SWHs. Such interventions, if successful, would dramatically speed up the roll out of SWHs in South Africa. In addition the study sought to determine the barriers to the uptake of SWHs by policyholders in the case of the two insurance companies that currently have SWH programmes in operation. Data was collected through interviews with representatives in the insurance industry and a range of SWH industry stakeholders and consumers. The literature review focused on SWH policies and regulations and corporate and marketing theories. The material on transition in socio-technological systems proved especially useful in understanding the complex dynamics of the study topic. The conclusion drawn from the research is that the South African insurance industry has the capacity and opportunity to drive the penetration of SWH technology. The opportunity is, however not being exploited to anywhere near its potential. The entire system is geared towards providing a particular ‘business-as-usual’ solution. Analysis conducted in this study confirms that the system is in a “locked-in” state and extremely resistant to change. If the opportunity is to be acted on, to supplant the dominant technology for water heating installed by the insurance industry with what is currently a niche technology (SWHs), an external landscape shock is almost certainly needed. This shock to the system could be aided by interventions that target a change in the current system’s logic. The study provides some suggestions in this regard. / AFRIKAANSE OPSOMMING: Suid-Afrika staar ‘n energie krisis in die gesig. Aan die een kant is die bestaande elektrisiteitsvoorsiening nie genoeg om plek te maak vir die toekomstige vraag na elektrisiteit nie en aan die ander kant word meeste van Suid-Afrika se elektrisiteit opgewek deur steenkoolaangedrewe kragstasies met gevolglike probleme as gevolg van vrylating van kweekhuis-gasse. Die Suid-Afrikaanse regering het ‘n teiken vir hernubare energie om 23% op te maak van die land se totale energie verbruik teen 2013. Hierdie teiken sou potensieel bereik kon word deur die bereiking van ‘n ander van die land se teikens, naamlik die instalering van een miljoen sonverhitters. Op ‘n tegniese vlak verteenwoordig sonverhitters ‘n lewensvatbare hernubare energie alternatief vir Suid-Afrika. Dit is ‘n beproefde tegnologie wat die potensiaal het om ‘n groot impak te hê op die elektrisiteit kapasiteitsprobleme van die land. Sonverhitters kan ‘n verskeidenheid van warm water behoeftes bevredig, van groot industrieë tot tuisverbruik. Meeste warm water in Suid-Afrikaanse huise word verhit deur standaard elektriese geisers. Daar bestaan geen tegniese hindernisse om hierdie geisers deur sonverhitters te vervang en tot 70% van die water verhittings energie rekening te bespaar nie. Water verhitting maak tans 40% van die totale huishoudelike elektrisiteits verbruik op. Die huishoudelike verbruik is 20-30% van die nasionale verbruik en selfs hoer gedurende piek. Op die makro skaal is die uitrol van sonverhitters heeltemal skaleerbaar. Die voordele van die installering van sonverhitters val die verbruiker toe in die vorm van finansiele besparing oor die lang termyn en vir die samelewing as geheel in die vorm van emissie besparings. Bewustheid van die voordele is aan die groei by die algemene publiek, kommersiele instansies en by die regering. Verkope het begin optel as gevolg van onder andere die elektrisiteits prysverhoging en die staatssubsidies vir sonverhitters aangebied via die nasionale elektrisiteits toevoer maatskappy, Eskom. A nasionale bouregulasie wat enegie doeltreffende waterverhitting sal afdwing op nuwe geboue is reeds opgestel en dit word verwag dat hierdie regulasie in plek sal wees teen middel 2011. Die koers van verandering van elektriese water verhitters na sonkrag bly egter teleurstellend laag. Die sonverhittings industrie in Suid-Afrika maak minder as 10% van die totale water verhittings mark uit. Hierdie studie het beoog om die geleenthede sowel as die moontlike versperrings tot die skepping van sonverhittings programme in die versekerings bedryf uit te wys. Die versekerings bedryf koop en installeer ongeveeer 50% van alle standaard elektriese geisers in Suid-Afrika as gevolg van elektriese geisers wat breek na die vervaardiger se waarborg verval het . As gevolg hiervan bestaan daar ‘n geleentheid vir intervensies wat polishouers aanmoedig om te verander na sonverhitters. Sulke intervensies, indien suksesvol, het die potensiaal om die uitrol van sonverhitters in die land dramaties te versnel. Verder het hierdie studie beoog om die versperrings tot die opname van sonverhitters uit te wys by twee versekerings maatskappye in Suid-Afrika wat wel sonverhittings programme het. Data is versamel deur onderhoude met verteenwoordigers van die versekeringsbedryf en ‘n reeks sonverhitting industrie belanghebbendes en verbruikers. Die literatuurstudie het gefokus op sonverhittings beleid en regulasies en korporatiese en bemarkings teorie. ‘n Literatuurstudie in oorgang in sosio-tegnologiese sisteme was veral nuttig om die komplekse dinamika van die sisteem te verstaan. Die gevolgtrekking van hierdie studie is dat die Suid-Afrikaanse versekeringsbedryf wel die kapasiteit en geleentleid het om die penetrasie van sonverhittings tegnologie te dryf. Hierdie geleentheid word egter nie gebruik tot sy volle potensiaal nie. Die ganse sisteem is gerat om ‘n spesifieke tegnologie op ‘n sekere manier te verskaf. Analise in hierdie studie bevestig dat die sisteem in ‘n geslote staat is en daar is uiterste teenkanting tot verandering. Indien hierdie geleentheid om die dominate tegnologie vir waterverhitting geinstaleer deur die versekerings bedryf te verplaas met wat op die oomblik nog ‘n niche tegnologie is (sonverhitters), is ‘n eksterne landskap skok nodig. Hierdie skok tot die sisteem kan aangehelp word deur intervensies wat ‘n verandering in die huidige sisteem logika teiken. Hierdie studie bied ‘n paar voorstelle in hierdie verband.

This final thesis deals coucerned with design of heating in the children´s home. The object has basement and three floors. The objectis heated by means of panel and tubular heaters. The heat source (ga condensing boiler) is located in a technical room.

Thesis (MBA)--University of Stellenbosch, 2011. / The government has stated its intentions to increase the usage of solar water heating (SWH) through its National Solar Water Heater Programme (NSWHP). As described in the report, increased adoption of SWH would have a number of benefits for South Africa. Firstly, replacement of electric geysers by SWHs would contribute to the meeting of energy efficiency targets through the reduction of energy consumption. Secondly, the widespread adoption of SWHs would help SA to meet its renewable energy targets. Thirdly, it would result in growth in the SWH industry, including the manufacturing, installation and related sectors, thereby contributing to an increase in 'green' jobs. It would have the socio-economic benefit of energy security for South Africans. The research report looks at the factors influencing the SWH industry's future growth from the point of view of the suppliers. It considers the interplay between consumers (market demand), government (public policy measures) and suppliers (businesses providing services related to SWH) to determine how government can support industry, how suppliers can grow their business and industry and how government and industry can work together to create the conditions for sustained market demand. As is discussed in the literature review, there are certain barriers to the adoption of SWH technology. As such, government intervention is needed to help overcome these barriers. The literature review recounts the available policy tools and considers how these have been applied in other countries to stimulate demand for SWHs and to support the local industry. The research report takes the form of a survey of SWH suppliers with the following aims: - To describe the industry in terms of its age, maturity and ability to scale up; - To determine the major barriers to the industry's growth; - To specify the appropriate public policy tools to overcome these obstacles to growth; - To establish how confident the industry is in the NSWHP and government efforts to promote the industry; - To provide a list of key success factors that are required for the industry's long-term, sustainable development. The report concludes that there are three criteria that would help the industry to become sustainable: market demand certainty, investment confidence and positive competition. Certainty of future market demand would build confidence in the industry for investors. In turn, increased investment would benefit the forces of positive competition.

Thesis (MBA)--Stellenbosch University, 2011. / This case study explores why the strategic positioning of the wall-panel heater, manufactured by Econo-Heat, justifies a green marketing strategy. The primary research objective is to provide Econo-Heat with a coherent marketing strategy framework, based on the outcome of the strategic analysis of the competitive positioning of the wall-panel heater. The following factors form the context of the study: the impact companies have on the environment, the energy crisis and the rising “green economy” in South Africa, and the increased consumer awareness about lifestyle consequences for the environment. The wall-panel heater uses convection-heating technology to warm rooms and has unique selling properties, such as being energy efficient, economical, effective and safe. Other space-heating products found in South Africa do not encapsulate all these qualities in one product. A strategic analysis done of the company revealed that the current competitive positioning of the wall-panel heater is a best-cost strategy. However, based on a literature review, the strategic analysis of the company and an exploration of the small household appliance consumer profile, the study found that the current competitive positioning of the wall-panel heater could be augmented. The combination of factors revealed by this study could be interpreted as push-factors towards the implementation of an applicable green marketing strategy that could support the re-positioning of the wall-panel heater to a broad-differentiated competitive positioning. These factors are the unique selling properties of the wall-panel heater, the lean manufacturing principles of the company, the rising green economy in the country, the energy crisis and the slow recovery from the global financial crisis in South Africa, as well as the unique characteristics of the environmentally-focused consumer. The view is held that green marketing can mitigate mass consumption. The case study suggests a future marketing strategy framework that consists of three combined elements. First, the argument is made that the unique selling properties of the wall-panel heater in combination with the unique operations of the company, against the backdrop of external factors that influence companies and consumers (i.e. the rising green economy and the energy crisis), could be utilised to discover new market space. The concept of “lateral marketing” is suggested as a framework should the company position itself to differentiate along the green dimension. Secondly, the “green marketing strategy matrix” is suggested as a framework to establish the size and greenness of its consumer segment, as well as the ability to differentiate along the green dimension. Lastly, the suggestion is made that the marketing objective of the company (its greenness) can be measured through the application of a “green marketing grid” that leads to innovation and the challenging of consumer behaviour. The combination of these elements is thought to form a coherent green marketing framework that could in future place the product at a strategic and competitive advantage within the space-heating industry.

Orientador: Vicente Luiz Scalon / Banca: Carlos Teófilo Salinas Sedano / Banca: Santiago Del Rio Oliveira / Resumo: As discussões recentes sobre sustentabilidade tem destacado os sistemas de aquecimento solar como alternativa adequada para aquecimento de água. Estes sistemas tem ganho notoriedade tanto para uso doméstico como no aquecimento de piscinas. Um dos aspectos que é frequentemente destacado como principal dificuldade para a sua popularização, entretanto é o custo de sua implantação. Uma das formas de reduzir este custo é minimizando o número de componentes e simplificando o sistema. Nesta linha de desenvolvimento muito tem se discutido sobre o uso de sistemas integrados coletor-armazenador (ICS). Baseando-se nestas avaliações, este trabalho pretende estudar diferentes configurações geométricas de coletores solares com armazenador integrado do tipo cubóide e verificar a influência sobre o aproveitamento de energia térmica quando se utiliza diferentes dispositivos para direcionar o fluxo de água quente. A partir de simulações numérico-computacionais é possível identificar as geometrias que apresentam melhor estratificação térmica no armazenador. A estratificação da temperatura em um armazenador é um fator extremamente importante no estudo de coletores solares, pois determina a porção de temperatura mais elevada. O modelo base, validado experimentalmente na literatura, foi utilizado com condições de fluxos de calor incidente e de perda por resfriamento constantes com boa concordância de resultados. Modificações geométricas foram implementadas e avaliadas para otimizar os parâmetros de projeto deste tipo de coletores solares integrados. Outras análises alterando o volume do sistema coletor-armazenador foram realizadas: um com 200 litros de capacidade e outro com 300 litros, de maneira a estabelecer um tamanho ótimo do sistema. Para visualizar a estratificação do armazenador... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Recent discussions highlighted the sustainability of solar heating systems as an apropriate alternative for heating water. These systems has gained prominence for both household and swimming pool heating. One aspect that is often highighted as the main obstacle to its popularity is the cost of its implementation. One way to reduce this cost is to minimize the number of components and simplifying the system. In this field of development has long been discussed about the use of integrated collector-storage (ICS). Based on these evaluations, this work analyzes different geometrical configurations of integrated solar collector-storage with storage type cuboid and the influence on the use of thermal energy when you use different devices to direct the flow of hot water. From numerical-computational simulations, the geometry with better thermal stratification in the storage can be identified. the stratification of temperature in a storage is an extremely important factor in the study of solar collectors, because it determines the portion of higher temperature. The base model, experimentally validated in the literature, was used with constant conditions of incident head flux and loss for cooling. Geometric changes were implemented and evaluated to optimize the design parameters of this type of integrated solar collectors. Further analysis by changing the volume of the collector-storage system were carried out: a 200 liter capacity and another with 300 liters, in order to establish and optimum size of the system. To view the stratification of the storage, images with the temperature profile are shown at the end of the heating and cooling periods and the following graphics show the stratification coefficient. The CFD method allowed to obtain results with good agreement with those used as the basis from the literature. Results... (Complete abstract click electronic access below) / Mestre

The increased penetration of renewable energy sources poses new challenges for grid stability. The stochastic and uncontrollable generation of solar and wind power cannot be adjusted to match the load profile, and the transition away from traditional synchronous generators is reducing the grid capacity to arrest and recover from frequency disturbances. Additionally, the distributed nature of many renewable energy sources makes centralized control of generation more complicated. The traditional power system paradigm balances the supply and demand of electricity on the grid by regulating generation. As this becomes more difficult, one alternative is to adjust the load instead. This is not entirely novel, and utilities have incentivized large industrial customers to reduce consumption during peak hours for years. However, the residential sector, which constitutes 37% of electricity consumption in the U.S., currently has very little capacity for load control. Smart electric water heaters provide utilities with an appliance that can be remotely controlled and serves as a form of energy storage. They have very fast response times and make up a large amount of residential energy consumption, making them useful for load peak shifting as well as other ancillary grid services. As smart appliances become increasingly widespread, more and more devices can be brought into the utility's control network and aggregated into a flexible resource on a megawatt scale. This work demonstrates the usefulness of aggregated electric water heaters for peak shifting and frequency response. Because a large number of assets are required, emulators are developed based on observations of real devices. Emulated water heaters are then connected to an energy resource aggregator using an internet-of-things network. The aggregator successfully uses these assets to shift consumption away from peak hours. An algorithm was developed for detecting upward frequency disturbances in real-time. The aggregator uses this algorithm to show that an aggregation of water heaters is well-suited to respond to these frequency disturbances by quickly adding a large amount of load to the grid.

Les défis environnementaux et l'augmentation de la population viennent en preuve de l'importance de réfléchir à d'autres moyens de production tout en maintenant la sécurité et la fiabilité du système électrique. La sûreté du système électrique exige à tout moment que la production soit égale à la demande des consommateurs, pour ça, différentes solutions sont déjà mises en place, ces solutions consistent à mettre en marche des moyens de pointes couteux et polluants pendant les périodes de pointes, mais comme les moyens de production son insuffisants et vue la difficulté d'exploitation de nouveaux moyens de production, une nouvelle réflexion sur la gestion de la demande est apparue; celle-ci se base sur la possibilité à gérer la demande du consommateur final au lieu de la satisfaire.L'objectif de la thèse est d'étudier la possibilité à rendre des services au système électrique en appliquant des actions de contrôle dites de DR (Demand Response), sur différents types de charges électriques. Ces actions de DR représentent des interruptions partielles appliquées sur les charges électriques de type thermique. Notre choix s'est basé sur ces types de charges parce que celles-ci emmagasinent de la chaleur respectivement dans l'air et dans l'eau; qui peut être restituée pendant la période de contrôle ou d'interruption. Néanmoins, il existe un effet négatif qui suit le contrôle de ces charges car l'énergie effacée de ces charges est reportée à l'instant de reconnexion de celles-ci; ce report prend la forme d'un pic de consommation nommé CLPU (Cold Load Pick-Up) et qui apparait au moment de la reconnexion. Le CLPU représente un problème qui doit être géré, et sa magnitude dépend des types d'actions de contrôle qu'on veut implanter et aussi des conditions du système électrique (contingence, défaillance d'une unité de production ou besoin de réserve de puissance). Pendant la thèse, le CLPU est contrôlé et optimisé ainsi que la puissance effacée. Un cas d'étude est présenté sur la contribution des actions de gestion de la demande à l'ajustement entre la demande et la production et l'effet généré sur le réglage secondaire de fréquence.

Made available in DSpace on 2014-06-11T19:25:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-07-13Bitstream added on 2014-06-13T20:33:04Z : No. of bitstreams: 1 sales_fb_me_bauru.pdf: 1185139 bytes, checksum: ba8e8304a72e250dcb73d00e64d9a913 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / As discussões recentes sobre sustentabilidade tem destacado os sistemas de aquecimento solar como alternativa adequada para aquecimento de água. Estes sistemas tem ganho notoriedade tanto para uso doméstico como no aquecimento de piscinas. Um dos aspectos que é frequentemente destacado como principal dificuldade para a sua popularização, entretanto é o custo de sua implantação. Uma das formas de reduzir este custo é minimizando o número de componentes e simplificando o sistema. Nesta linha de desenvolvimento muito tem se discutido sobre o uso de sistemas integrados coletor-armazenador (ICS). Baseando-se nestas avaliações, este trabalho pretende estudar diferentes configurações geométricas de coletores solares com armazenador integrado do tipo cubóide e verificar a influência sobre o aproveitamento de energia térmica quando se utiliza diferentes dispositivos para direcionar o fluxo de água quente. A partir de simulações numérico-computacionais é possível identificar as geometrias que apresentam melhor estratificação térmica no armazenador. A estratificação da temperatura em um armazenador é um fator extremamente importante no estudo de coletores solares, pois determina a porção de temperatura mais elevada. O modelo base, validado experimentalmente na literatura, foi utilizado com condições de fluxos de calor incidente e de perda por resfriamento constantes com boa concordância de resultados. Modificações geométricas foram implementadas e avaliadas para otimizar os parâmetros de projeto deste tipo de coletores solares integrados. Outras análises alterando o volume do sistema coletor-armazenador foram realizadas: um com 200 litros de capacidade e outro com 300 litros, de maneira a estabelecer um tamanho ótimo do sistema. Para visualizar a estratificação do armazenador... / Recent discussions highlighted the sustainability of solar heating systems as an apropriate alternative for heating water. These systems has gained prominence for both household and swimming pool heating. One aspect that is often highighted as the main obstacle to its popularity is the cost of its implementation. One way to reduce this cost is to minimize the number of components and simplifying the system. In this field of development has long been discussed about the use of integrated collector-storage (ICS). Based on these evaluations, this work analyzes different geometrical configurations of integrated solar collector-storage with storage type cuboid and the influence on the use of thermal energy when you use different devices to direct the flow of hot water. From numerical-computational simulations, the geometry with better thermal stratification in the storage can be identified. the stratification of temperature in a storage is an extremely important factor in the study of solar collectors, because it determines the portion of higher temperature. The base model, experimentally validated in the literature, was used with constant conditions of incident head flux and loss for cooling. Geometric changes were implemented and evaluated to optimize the design parameters of this type of integrated solar collectors. Further analysis by changing the volume of the collector-storage system were carried out: a 200 liter capacity and another with 300 liters, in order to establish and optimum size of the system. To view the stratification of the storage, images with the temperature profile are shown at the end of the heating and cooling periods and the following graphics show the stratification coefficient. The CFD method allowed to obtain results with good agreement with those used as the basis from the literature. Results... (Complete abstract click electronic access below)

Orientador: Jose Antonio Siqueira Dias / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-14T11:25:46Z (GMT). No. of bitstreams: 1 Ormenese_Marcela.pdf: 17981897 bytes, checksum: c7b7714358950bc575686565e846f762 (MD5) Previous issue date: 2009 / Resumo: Os sistemas de aquecimento solar disponíveis comercialmente, embora proporcionem boa economia de energia elétrica, não apresentam bom desempenho em dias com baixa radiação, pois o boiler é automaticamente preenchido com água fria toda vez que ocorre consumo de água quente. Neste trabalho é proposto e estudado um sistema de aquecimento solar que é otimizado para proporcionar uma mínima utilização da energia elétrica no auxílio ao aquecimento de água. Um controlador fuzzy analisa a intensidade da radiação solar, a temperatura da água dentro do boiler, a quantidade de água dentro do boiler e controla a entrada de água fria no boiler, otimizando o sistema. Foram modelados dois sistemas de aquecimento: um convencional e este sistema com o controlador fuzzy; e, através de simulações, suas eficiências foram comparadas. Os resultados obtidos em simulação mostram que o sistema proposto com controlador fuzzy apresenta eficiência superior aos sistemas convencionais. Para um período de três dias de inverno, com baixa radiação solar, o sistema convencional consumiu uma energia elétrica de 10,08 kWh enquanto que o sistema proposto consumiu apenas 1,86 kWh. / Abstract: Although significant savings in electrical energy are achieved with commercially available solar water heaters, they do not present a good performance in days that the radiation is not good, because the boiler is filled with cold water whenever the hot water is used. In this work, a new solar heating system, which minimizes the use of electrical energy, is proposed. The proposed system uses a fuzzy controller that analyzes the intensity of solar radiation, the temperature of the water inside the boiler and the volume of water inside the boiler, to actuate on a On/Off valve which controls the boiler's input of cold water. Two solar heating systems were modeled: a conventional system and the new proposed system with the fuzzy controller; and their efficiencies were compared using computer simulations. The obtained results show that the proposed system with the fuzzy controller presents a much higher performance when compared to the traditional system. Simulation results indicate that for a three winter days period, with low intensity solar radiation, the conventional system consumed 10.08 kwh of electrical energy while the proposed system needed only 1.86 kwh to achieve the same performance. / Universidade Estadual de Campi / Eletrônica, Microeletrônica e Optoeletrônica / Mestre em Engenharia Elétrica

This diploma thesis deals with the design of a thermal scheme of steam power plant. The introductory part of the thesis is dedicated to theory about thermal power plants, especially those with supercritical steam parameters. In the following parts, there is a design of the thermal scheme of the coal burning power plant. First separate parts, then all interconnected. The last chapter deals with energy and media balance involved in the process.