This research is aimed to study the system performance for a large solar hot water system constructed by connecting a series of small domestic natural circulation systems. There are few studies on this type of large solar hot water system available. The major concern is that when circulation pump is on, there forms a short flow between inlet and outlet of each storage tank of natural circulation solar hot water unit. Therefore, water does not have chance to flow though the collector by thermosyphon and system performance can be lowered down drastically. This thesis presents the numerical simulation study for the control and system operating parameters effects on the system performance to provide important information both for users and system designers.

Renewable energy has become the world's fastest growing energy source as a direct result of increasing concerns about the environmental damage that is being caused by fossil fuel and nuclear energy use. With the exception of large-scale hydro, however, very little of Australia's electricity is supplied from renewable energy. Due to our lack of experience with the use of most renewable energy technologies and the associated lack of knowledge regarding their true potential, doubts remain as to how much electricity could be generated or displaced by renewable energy. Although renewable energy industries in Australia have recently begun to experience strong growth, this growth could be curtailed if there is a lack of faith in the potential for renewable energy. The aim of this study is to further our understanding of the potential for renewable energy to contribute to electricity supply in Australia. This aim is achieved through the development and demonstration of methodologies for estimating potential electricity production from key renewable energy resources. The study demonstrates how methodologies for assessing the potential contribution of key renewable energy resources to electricity supply in Australia can be developed utilising a spatial assessment of important resource variables within the context of plausible utilisation of renewable energy resources. A literature review provides the basis for an assessment of the current state of knowledge regarding the use of renewable energy for electricity supply in Australia. The range of different renewable energy technologies is canvassed, brief descriptions of the technologies are presented and an appraisal is made of their commercial development status. The extent to which different renewable energy technologies have been utilised for electricity supply in Australia and prospects for near-future developments are described. Scenario analysis is used to provide insights into future development paths for renewable energy. This assists in the identification of key renewable energy technologies that will be examined in more detail and it helps in the setting of parameters for assessments of these technologies. Three scenarios are presented and these provide a framework for an analysis of possible contributions by renewable energy to electricity supply in Australia. Of those technologies that could potentially make significant contributions to electricity supply in the near term, utility scale wind energy, domestic rooftop photovoltaics (rooftop BIPV) and domestic solar hot water (SHW) stand out as being key technologies where further research in relation to resource assessment would be beneficial. The dispersed nature of the resource bases utilised by these technologies has made it difficult to assess how much electricity they could generate or displace. Conventional methods of assessing electricity generation or displacement, based upon project or site-specific analyses, have not proven amenable to analyses of the total amount of electricity that could be generated or displaced by these technologies throughout Australia. Therefore, alternative methods for assessing the potential of these technologies are needed. New models for analysing wind, BIPV and SHW performance are developed in this study. These models demonstrate the application of Geographical Information Systems (GIS) for wind, BIPV and SHW resource mapping. Wind energy maps for Australia are created showing actual wind speeds suitable for use at elevations appropriate for wind turbines. These maps represent significant advances over traditional wind atlases used in other nations due to their presentation of estimated actual wind speeds, rather than isovent lines for idealised wind speed gradients. The use of GIS for analysing BIPV and SHW resources also represents a significant departure from traditional modelling processes and demonstrates a means of overcoming important limitations of existing BIPV and SHW evaluation tools. The wind, BIPV and SHW resource mapping processes that have been developed and applied in this study show how broad-area assessments of electricity supply or displacement can be produced for technologies where spatial variations in key performance attributes constrain the use of traditional modelling processes.

Thesis (MTech(Electrical Engineering)) -- Cape Peninsula University of Technology, 2014 / Today the building energy modeling industry is facing a number of challenges, the advanced programs or methods developed for building energy modeling, are very technical and complex to be used, especially for earlier designs, and the easy programs or methods are not accurate. Moreover, more than a hundred programs developed for energy modeling, have been used in the same building, but most of the time the results differed by about 30%. That is why this thesis has developed a new building energy model in System Modeling Language (SysML), in order to meet, at the same time, the accuracy and the simplicity to be used for future and existing buildings. In this thesis, SysML has been used to develop an energy model and to set up an automation system to the existing building. SysML can do more than simulations, but this thesis is limited to only the simulations steps by using easy applications of SysML and fewer diagrams which could develop in a complete building energy model. SysML is the extension of Unified modeling Language (UML), which uses fewer diagrams than UML. SysML is simple, open and more flexible to be used in any Engineering System. The previous chapter describes SysML and gives the overview and the platform of SysML. The simulations of SysML in this project have been developed through Enterprise Architect and Mat lab software. The inputs used to simulate the program are the parameters of the existing building chosen for modeling that is a student residential building complex located in Stellenbosch, Western Cape in South Africa. Automation system program used in this thesis was based on the norms and building standards of South Africa, renewable energy and the requirements of the buildings’ occupants, in order to meet energy efficiency and safety of the occupants.

Submitted by CRISTIANO PANSANATO null (pansanato.cristiano@gmail.com) on 2017-01-12T21:03:45Z No. of bitstreams: 1 Cristiano Pansanato - Dissertação de Mestrado - 2016.pdf: 4251034 bytes, checksum: f23b5995e15e89e575b69d4b742fb372 (MD5) / Approved for entry into archive by LUIZA DE MENEZES ROMANETTO (luizamenezes@reitoria.unesp.br) on 2017-01-16T18:33:30Z (GMT) No. of bitstreams: 1 pansanato_c_me_bauru.pdf: 4251034 bytes, checksum: f23b5995e15e89e575b69d4b742fb372 (MD5) / Made available in DSpace on 2017-01-16T18:33:30Z (GMT). No. of bitstreams: 1 pansanato_c_me_bauru.pdf: 4251034 bytes, checksum: f23b5995e15e89e575b69d4b742fb372 (MD5) Previous issue date: 2016-12-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A busca mundial for fontes de energia que garantam um crescimento sustentável tem marcado o século XXI. Nesse cenário, o Brasil é beneficiado, com diversas fontes de energias viáveis nas condições atuais e outras promissoras num cenário de médio e longo prazo. A utilização da energia solar convertida em energia térmica ou elétrica apresenta-se como uma destas alternativas. Explorar a energia solar de forma viável economicamente e melhorar a eficiência de captação e transformação são os grandes desafios que se apresentam. Neste contexto, este estudo se propôs a analisar experimentalmente o desempenho de um Sistema Acoplado, composto por coletores planos com e sem cobertura. O objetivo é reduzir o custo de implantação de um sistema de aquecimento, uma vez que o os coletores sem cobertura são mais baratos. Além disso, dependendo das características de implantação, é ainda possível aumentar a eficiência global do sistema através de um pré-aquecimento da água no coletor sem cobertura, aproveitando a maior eficiência térmica para temperaturas de operação próximas a do ambiente. Para estudo do Sistema Acoplado, um outro sistema composto apenas por coletores com cobertura foi montado e denominado Sistema Simples. Desta forma, com os dois aparatos montados e devidamente instrumentados foi possível obter resultados para as mesmas condições ambientais de teste. Assim, diversos esquemas de controle também puderam ser testados e analisados tanto na operação do Sistema Acoplado como do Sistema Simples. Resultados comparativos avaliando as condições de saída, energia útil e armazenada e eficiências térmicas foram apresentados e comparados para os dois sistemas. / The global search for energy sources that ensure sustainable growth has marked the 21st century. In this scenario, Brazil is benefited, with several viable sources of energy under current conditions and other promising sources in a medium and long-term scenario. The use of solar energy converted into thermal or electric ones presents itself as one of these alternatives. Using solar energy in a cost-effective way and improving the performance for capturing and transforming are the major challenges nowadays. In this context, this study proposed to analyze experimentally the performance of a Coupled System, composed by glazed and unglazed flat collectors. The purpose of this system is to reduce the installation costs of a heating system, since the unglazed collectors are less expensive. In addition, depending on its implementation characteristics, it is possible to increase the overall efficiency of the system by preheating the water in an unglazed collector, taking advantage of its higher thermal efficiency at nearby operating and ambient temperatures. For analysis of Coupled System, another system composed only of glazed collectors was assembled and denominated as Simple System. In this way, with the two devices mounted and instrumented some results can be obtained for the same environmental test conditions. Thus, several control schemes could also be tested and analyzed in the operation of both systems. Comparative results evaluating the output conditions, useful and stored energy and thermal performances are presented and compared for the systems.

Domestic solar hot water units, if properly designed, are capable of providing all hot water needs in an environmentally friendly and cost-effective way. Despite 50 years of development, commercial technology has not yet achieved substantial market penetration compared to mainstream electric and gas options. Therefore, alternate designs are warranted if they can offer similar or greater performance for a comparable cost to conventional units. This study proved that such alternatives are possible by designing and testing two novel solar hot water systems (SHWS). The first system used compound parabolic collector (CPC) panels to concentrate solar energy and produce steam. The steam moved from a rooftop downward into a heat exchange pipe within a ground level water tank, heating the water, condensing and falling into a receptacle. The operation was entirely passive, since the condensate was pulled up due to the partial vacuum that occurred after system cooling. Efficiencies of up to 40% were obtained. The second system used an air heater panel. Air was circulated in open and closed loop configuration (air recycling) by means of a fan/blower motor and was forced across a compact heat exchanger coupled to a water tank. This produced a natural thermosiphon flow heating the water. Air recycling mode provided higher system efficiencies: 34% vs. 27%. The concurrent development of an analytical model that reasonably predicted heat transfer dynamics of these systems allowed 1) performance optimisation for specific input/starting operating conditions and 2) virtual design improvements. The merit of this model lay in its acceptable accuracy in spite of its simplicity. By optimising for operating conditions and parameter design, both systems are capable of providing over 30 MJ of useful domestic hot water on clear days, which equates roughly to an increase of 35°C in a 200 L water tank. This will satisfy, on average, daily hot water requirements for a 4-person household, particularly in low-latitude regions (eg. Queensland). Preliminary costing for these systems puts them on par with conventional units, with the passive, remotely coupled, low maintenance, CPC SHWS comparable to higher end models. The air heater SHWS, by contrast, was much more economical and easier to build and handle, but at the trade-off cost of 1) the need for an active system, 2) increased maintenance and running costs and 3) the requirement for a temperature control mechanism that would protect the panel body by dumping hot air trapped inside if stagnation were to occur.

This thesis is aimed to enable energy optimization of combined water heating system. The first part deals with the assessment of the general view of thermal solar systems with autonomic power from photovoltaics and description of a particular solar system for energy optimization. Then there is chosen the control system conception based on single-board computer Raspberry Pi, which is complemented by auxiliary measuring and controlling circuit. In the following chapters is described design and implementation of software for control system including web interface. The remote monitoring and controlling of solar heating system is the main purpose of web interface.

This master thesis aims to design the heating system and HDW preparation in an apartment building. The first variant deals with condensation gas boiler as the only energy source, while the second variant combines the gas boilers with the solar thermal system. The apartment building is located in Prag and has three above-ground floors and a basement. In the basement is the technical room. Convectors are being used for heat distribution. The theoretical part deals with the introduction to the solar thermal system.

In the summer of 2007, a single neighbourhood in downtown Toronto contributed at least 13 percent of all residential grid???tie solar photovoltaic (PV) systems sold in the Canadian province of Ontario. On average, PV purchaser households produced 37 percent as much electricity as they consumed. This research investigates solar energy adoption in a community case study. Specifically, it investigates why some residents who sign up for a solar resource assessment through a community solar energy initiative (CSEI) decide to purchase, and others decide not to purchase in the short???term. Characteristics and perceptions of potential adopters are analyzed to better understand their motivations and barriers to adoption. Community energy projects became an official public policy goal in Ontario, with the passing of the Green Energy and Green Economy Act in 2009. Approximately 80 percent of Ontario???s anticipated generation capacity will need to be built, replaced or refurbished within 15 years. In this context, the Ontario Ministry of Energy, Ontario Power Authority, and Deloitte (one of Canada???s leading professional services firms), have partnered with a ???green benefit??? fund, the Community Power Fund, to help local community groups access resources to develop and establish renewable energy projects. Understanding solar energy adoption in a community context is therefore important to improve the effectiveness of such policies, including the disbursement of multi???million dollar grant funds. Differences between purchasers and non???purchasers in respect of adoption behaviour were found in this study to cluster around two general themes. The first theme concerns differences in compatibility of both the concept of solar energy systems, and their physical attributes, with characteristics of potential adopter households. Some compatibility issues are straightforward, e.g. availability of roof space with a southern orientation. Others are more complex, involving several interrelated perceptual and socio???demographic factors. For instance, while both purchasers and non???purchasers rated cost as a very important barrier, purchasers rated the motivation of solar energy systems to reduce climate change higher relative to the barrier of high financial costs than did non???purchasers. Purchasers were also more likely to possess a graduate degree, while non???purchasers were more likely to hold a professional degree. The second general theme relates to potential adopters??? trust and stake in the ability of the community???based initiative to reduce barriers in the adoption process. Since two types of solar energy systems are considered in the case study???PV and thermal (hot water)???differences are explored between each of three respondent groups: solar PV purchasers, solar hot water (SHW) purchasers, and non???purchasers. iv Surveys were used to gather data on adopter perceptions and characteristics. A participatory research design helped identify the research topic. Two main bodies of literature???community???based social marketing (CBSM) and diffusion of innovations theory???were drawn upon to conceptualize the adoption process and interpret the survey findings. These include five models of human behaviour that can be used to guide the design of CBSM campaigns. Diffusion theory was used as a basis for discussing ???perceived innovation attributes???. The study takes an integrated approach by considering both social and technical aspects of solar energy adoption, together with the issues of fuel substitution and household electricity demand.