The performance of two innovative collector-loop heat exchangers used in pumped circulation solar water heaters was investigated experimentally and numerically, and TRNSYS simulation models were developed for evaluating long-term performance. The heat exchangers evaluated are a narrow gap mantle on a vertical tank and a falling film system in a standard gas hot water tank. The falling film system is based on minor changes to a mass produced tank and does not require the addition of a special purpose heat exchanger. The heat exchangers were assessed for a range of operating conditions to quantify the overall heat exchanger UAhx value and the effect of thermal stratification in the tank. Flow visualisation experiments and CFD modelling were also performed to provide detailed understanding of the operation characteristics of the heat exchangers. For each heat exchanger, the measured and computed collector loop side heat transfer coefficients were correlated by developing new Nusselt number versus Reynolds and Prandtl number functions. New heat transfer correlations were developed for both types of heat exchanger and have been implemented into full solar water heater simulation models in TRNSYS. Predictions of tank stratification conditions in each heat exchanger were in good agreement with experimental data. Compared to a standard direct circulation system, the annual performance of the mantle system and falling film system are 8% and 18% less respectively. The decrease in system performance is due to the heat exchanger penalty and reduced thermal stratification in the storage tank, however they have the added features of freeze protection and suitability for hard water areas. They are also cheaper to manufacture than convectional heat exchange systems. The annual performance of a falling film solar water heater was shown to be affected by de-stratification if an in-tank electric booster was used. However, improved performance can be achieved if an advanced switching controller is used to modulate the flow rate such that the collector return temperature is always higher than the temperature in the top of the tank.

In this present world order of growing information, communication and technological advancement, it is primordial that climate change adaptation and mitigation efforts seeks to make people resilient to inevitable climate inconsistency through the exploitation and development of renewable energy sources. Though climate impacts are global, the population most at risk is predominantly from developing countries, particularly poor communities who have experienced multi-layered threats from floods, droughts and energy supply, just to mention a few. This explains why sustainable development is at the heart of all development trajectories in the world today, specifically the post-2015 development tenets. Climate change adaptation and mitigation requires international collaboration from all nations in order to get an effective and unified response to climate change. Building a critical mass for action and an institutional memory to sustain policies and efforts is crucial. A resilient-based approach to climate mitigation and adaptation founded on a crisis-driven reaction to communities vulnerable to climate threat will boost quality of life through the provision and safeguarding of safety nets for the poor. Solar water heaters, a renewable energy source, are here considered as a critical option to South Africa’s coal-driven economy as a means of alleviating energy poverty in rural and low-income communities, to be more precise. Therefore, SWHs have become the epicentre of sustainable development policies and climate change mitigation efforts in South Africa. So far, this device has attracted the attention of local governments in the country who view it as a game changer in the field, particularly towards greenhouse gas emission and energy conservation. The contour of this thesis is to assess the impact of solar water heaters on sustainable development. Although it is generally difficult to assess the real impact of technology on people, that of SWHs was established by asking questions about livelihood before, during and after the introduction of this device.

Orientador: Carlos Roberto Padovani / Banca: Osmar de Carvalho Bueno / Banca: Paulo André de Oliveira / Banca: Rogério Antonio de Oliveira / Banca: Marie Oshiiwa / Resumo: Atualmente, fontes de energia renováveis são exploradas e usadas para o desenvolvimento da sociedade e se destacam por serem mais limpas e menos poluentes que as fontes de energia não renováveis. Entre estas fontes de energia renováveis, a energia solar é uma das mais aproveitadas, usada em sistemas fotovoltaicos para geração de energia elétrica e em sistemas de aquecimento solar de água, sendo a segunda utilização citada a mais conhecida, podendo ser vista em residências, comércios e indústrias. O sistema de aquecimento solar tem entre seus objetivos, o de proporcionar economia de energia elétrica, pois fornece água quente sem a necessidade de utilizar sistemas elétricos, como o chuveiro elétrico, que é um dos aparelhos que mais consome energia. Para proporcionar economia do consumo de energia elétrica, minimizar impactos ambientais, redirecionar investimentos em novas fontes geradoras de energia elétrica, o Governo do Estado de São Paulo, em conjunto com a Companhia de Desenvolvimento Habitacional e Urbano do Estado de São Paulo - CDHU, como política de habitação, instalaram, nas residências de interesse social construídas a partir de 2007, o sistema de aquecimento solar de água. Na cidade de Ourinhos - SP, o conjunto habitacional Helena Braz Vendramini foi contemplado pelo sistema de aquecimento solar de água nas residências, porém, na mesma cidade, existe outro conjunto habitacional, o Orlando Quagliato, mas, por ser mais antigo, não possui o sistema de aquecimento solar, fator que motivou o presente estudo quanto à busca de determinantes para a viabilização e recomendação de características fundamentais para a otimização do aproveitamento de fonte de energia alternativa. O objetivo desta pesquisa foi aplicar procedimentos e técnicas de análise multivariada na avaliação do impacto econômico e na busca dos identificadores socioeconômicos fundamentais ... / Abstract: Nowadays, renewable energy sources are exploited and used for the development of society and stand out for being cleaner and less polluting than non-renewable energy sources. These renewable energy sources, solar energy is one of the most exploited, used in photovoltaic systems for power generation and solar water heating systems, the second use cited the best-known and can be seen in homes, businesses and industries. The solar heating system has among its objectives, to provide energy saving because it provides hot water without the need for electrical systems, such as electric shower, which is one of the devices that consume more energy. To provide economy of energy consumption, minimize environmental impacts, redirect investments in new sources of electricity, the Government of the State of São Paulo, together with the Development Company Housing and Urban State of São Paulo - CDHU, as housing policy, installed in homes of social interest built from 2007, the solar heating system water. In Ourinhos - SP, Helena Braz Vendramini housing project was awarded the solar heating system water in homes, but in the same city, there is another housing project, the Orlando Quagliato, but being older, does not have the solar heating system, a factor that motivated this study and the search for determinants for the viability and recommendation of key features to optimize the alternative energy source to use. The objective of this research was to apply procedures and techniques of multivariate analysis in evaluating the economic impact and the pursuit of fundamental socioeconomic identifiers for the description of a rational use of water policy and energy in housing with and without solar water heating system. The results showed that differences between the housing are observed for combinations of consumption and socioeconomic variables and the association of positivity between these sets of variables was... / Doutor

M. Tech. Electrical Engineering. / Discusses the study objectives as follows: 1. Description of the extent of roll-out of SHW (Solar Water Heater) as a DSM (Demand Side Management) Programme in Botswana. 2. Identification of SWH implementation obstacles/barriers in Botswana. 3. Provision of a strategy for SWH data capture and verification in Botswana. 4. Evaluation of SWH performance through field measurements. 5. Prediction of SWH performance results using performance predictive simulation models. 6. Extrapolation/quantification of the impact of SWH. 7. Provision of energy management/planning/forecasting tool.

There is the potential to use solar energy as an energy efficient method of heating water, instead of using electricity. This study investigated the current barriers to the mass rollout of solar water heaters in South Africa and provided possible solutions to reduce these barriers. Local experts have already identified the key barriers to the rollout of solar water heaters and this study drew from the findings of international practises and applied these findings to the South African context. The barriers that are preventing the industry from developing are: the high price of solar water heaters, the lack of awareness of the technology, the absence of legislation, a tedious process for rebates, non–mandatory standards, insufficient training facilities leading to a shortage of skills and the low price of electricity. The research methodology was a blend of qualitative and a quantitative study including relevant theory supported by seven open-ended questionnaires completed by recognised industry specialists. The information gathered from the questionnaires was analysed and compared to the theory and international experience. The barriers to solar water heating can be overcome by having more government involvement in the development of policies to promote and educate the public on alternative energy sources. This lack of awareness on the technology can be improved by having awareness programmes in schools and frequent broadcasts on radio and television. There is a dire need for the development of cost effective financing mechanisms because the high costs of production influences the price of solar water heaters. Financial incentive models such as rebates, could be more effective in assisting the low and middle-income groups with partial funding for the purchase of the solar water heater. / Thesis (MBA)-University of KwaZulu-Natal, 2010.

During the last decade, Mexico City's air quality has deteriorated dramatically. Air pollution management has become a major issue, and a number of policies and campaigns aimed at reducing the volume of harmful emissions released into the atmosphere by vehicles and large-scale industries, have been implemented. / Lighting, office equipment, cooking, refrigeration, space heating, space cooling, ventilation, and water heating are the ultimate commercial uses of energy. The goal of this study is to determine if there is a potential market for solar water heaters that could provide hot water for a number of activities in the city, reducing the amount of fossil fuels burned for this purpose, thus contributing to decrease the amount of air pollutants to the atmosphere. / The results of this research show how a number of industries, public services and commercial activities need to be provided with both water and energy in large quantities, and are therefore potential users of solar thermal technologies.

Made available in DSpace on 2015-08-20T17:10:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-05-06. Added 1 bitstream(s) on 2015-08-20T17:25:42Z : No. of bitstreams: 1 000843148.pdf: 1252440 bytes, checksum: 0bb257659edd87f44be9d42ef4f29481 (MD5) / Atualmente, fontes de energia renováveis são exploradas e usadas para o desenvolvimento da sociedade e se destacam por serem mais limpas e menos poluentes que as fontes de energia não renováveis. Entre estas fontes de energia renováveis, a energia solar é uma das mais aproveitadas, usada em sistemas fotovoltaicos para geração de energia elétrica e em sistemas de aquecimento solar de água, sendo a segunda utilização citada a mais conhecida, podendo ser vista em residências, comércios e indústrias. O sistema de aquecimento solar tem entre seus objetivos, o de proporcionar economia de energia elétrica, pois fornece água quente sem a necessidade de utilizar sistemas elétricos, como o chuveiro elétrico, que é um dos aparelhos que mais consome energia. Para proporcionar economia do consumo de energia elétrica, minimizar impactos ambientais, redirecionar investimentos em novas fontes geradoras de energia elétrica, o Governo do Estado de São Paulo, em conjunto com a Companhia de Desenvolvimento Habitacional e Urbano do Estado de São Paulo - CDHU, como política de habitação, instalaram, nas residências de interesse social construídas a partir de 2007, o sistema de aquecimento solar de água. Na cidade de Ourinhos - SP, o conjunto habitacional Helena Braz Vendramini foi contemplado pelo sistema de aquecimento solar de água nas residências, porém, na mesma cidade, existe outro conjunto habitacional, o Orlando Quagliato, mas, por ser mais antigo, não possui o sistema de aquecimento solar, fator que motivou o presente estudo quanto à busca de determinantes para a viabilização e recomendação de características fundamentais para a otimização do aproveitamento de fonte de energia alternativa. O objetivo desta pesquisa foi aplicar procedimentos e técnicas de análise multivariada na avaliação do impacto econômico e na busca dos identificadores socioeconômicos fundamentais ... / Nowadays, renewable energy sources are exploited and used for the development of society and stand out for being cleaner and less polluting than non-renewable energy sources. These renewable energy sources, solar energy is one of the most exploited, used in photovoltaic systems for power generation and solar water heating systems, the second use cited the best-known and can be seen in homes, businesses and industries. The solar heating system has among its objectives, to provide energy saving because it provides hot water without the need for electrical systems, such as electric shower, which is one of the devices that consume more energy. To provide economy of energy consumption, minimize environmental impacts, redirect investments in new sources of electricity, the Government of the State of São Paulo, together with the Development Company Housing and Urban State of São Paulo - CDHU, as housing policy, installed in homes of social interest built from 2007, the solar heating system water. In Ourinhos - SP, Helena Braz Vendramini housing project was awarded the solar heating system water in homes, but in the same city, there is another housing project, the Orlando Quagliato, but being older, does not have the solar heating system, a factor that motivated this study and the search for determinants for the viability and recommendation of key features to optimize the alternative energy source to use. The objective of this research was to apply procedures and techniques of multivariate analysis in evaluating the economic impact and the pursuit of fundamental socioeconomic identifiers for the description of a rational use of water policy and energy in housing with and without solar water heating system. The results showed that differences between the housing are observed for combinations of consumption and socioeconomic variables and the association of positivity between these sets of variables was...

Thesis (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2016. / Solar energy is still not being used effectively in countries in the developing world, though it's a partial solution to the problem of shortage and expensive energy. Normally harvested through flat plate collectors, converting solar radiation into heat is the most direct application that can be effected in water heating systems. Many researchers have attempted to develop means of improving the efficiency of the flat plate solar energy collector; however there appears to be no evidence of any work regarding the effect of geometric configuration on the performance of flat plate solar collector. This study presents results obtained when comparing the performance of a solar water heating system equipped with three manufactured flat plate solar collector panels of numerically identical surface area but of different geometric configuration as they were individually attached to a typical geyser. Data was obtained inside a laboratory. The amount of heat acquired from flat plate collectors of solar energy depends primarily on their surface area that is exposed to the solar irradiance, however, the geometry of the collectors was thought that it might affect to some extent the amount of heat harvested. The circulation of the water from the panel to the geyser was due to the self-induced thermo-syphon effect. The results obtained during the test period (7 hours per day for two consecutive days) indicated that the system’s thermal efficiency was best when the square geometrical configuration collector was used. A dimensional analysis using the Π Buckingham method that was performed on the parameters affecting a flat plate solar collector yielded three dimensionless numbers that lead to a power law relationship which might be useful in enhancing solar water heating systems’ design.

The main purpose of this research project was to do a comparative study, by identifying a testing methodology for transient conditions, through which to allow the expression of the relative thermal performance of two DSWH collectors in comparison. The study started off by considering literature about Solar Domestic Water Heaters and National Standards-based test methods, most of which were for Steady State testing conditions. Thereafter establishing a testing methodology and setup, identifying factors to be considered. The results were analyzed and conclusions drawn. The hypothesis was to allow the reduction in the complexity of testing equipment and methods, and by doing transient condition testing and still utilizing the Hottel-Whillier-Bliss relationship as a way of expressing efficiency, the hypothesis was proven.

The study found that investing in solar water heater system (SWH) would be an economically, socially and environmentally viable option to implement within urban households; in which the hot water demand, volume of hot water consumption, water heating costs, and electricity tariffs are high. Investing in solar water heater technology should be the key focus of South African government; in order to enhance the wellbeing of the ordinary citizens. The study made use of the qualitative research approach to investigate solar water heater drivers and barriers; from the perspective of energy consumers. This will be achieved by focusing on the major drivers and barriers that consumers consider when making decisions on adoption of solar water heater system. It is believed that solar water heater drivers and barriers substantially influence the potential and urban development thereof. Solar heat is utilized in the residential sector for heating water for bathing, cleaning, washing and cooking food, but its availability is limited (Arora & Arora, 2013). Renewable energy has become a wild card internationally and regionally because of the technical, economic and environmental barriers affecting the disadvantaged individuals.