No description available.

This report is concerned with the performance of solar hot water units for laboratory and field use. A solar unit is defined as a system consisting of a collector, storage tank, piping system and controls. Older unites typically employ the thermosyphon principle (gravity) while more recent models use a water pump to circulate the water. Basically, the collector absorbs solar radiation and transfers thermal energy to the water flowing in the collector tubing. From the collector, the fluid is pumped to the storage tank at which point the hot water is available for usage. A literature search revealed that very little information was available concerning test procedures. The National Bureau of Standards (NBS) has generated proposed test procedures for separate testing of the collector and storage tank, but they do not include testing of the total system. The only other suggested test procedure found was by Stotter and Robinson, these authors include a discussion of the total system. Stotter and Robinson along with (NBS) provided the starting point for this report. In the report it is shown that qualitative properties are equally as important as quantitative properties. Quantitative properties are defined as temperature, flowrate, solar radiation or insolation, wind velocity and direction. Qualitative properties are defined as shade, weather resistance, corrosion resistance, location and maintenance. To determine which solar unit properties would be useful in comparing performance values, test reports along with the other references on solar unit testing were studied. After a review of all the reference material the following performance parameters were obtained and are believed to be of use in comparing solar units. These parameters are discussed in detail in the text of the report. 1. nth, the practical thermal efficiency 2. pSTOR, the heat storage coefficient 3. Q, the solar unit capacity 4. Ceff, capacity efficiency. It was found from the error analysis that the recommended instrumentation and test procedure, presented herein, should result in less than ± 10% error in the calculation of performance parameters. Temperature measurement error was found to be the largest contributor to the overall error. It is recommended that the test procedure herein be used for Florida Technological University testing of laboratory and field solar units, and the future work be performed to develop a method of rating solar units.

Thesis (MPA.) --University of Limpopo, 2016 / Refer to the document

Energy efficient technologies and renewable energy technologies are becoming less of a novelty in the American energy mix. These technologies offer the promise of a decreased dependence on foreign oil, considerable savings of energy bills, and protections for the environment. Despite the many potential benefits, these technologies face many barriers to adoption. The lack of renewable energy technologies and energy efficient technologies is particularly damaging in the State of Hawaii, where 90% of energy needs are met with imported fossil fuels. This report focuses on the current energy policies in Hawaii and the barriers to the incorporation of renewable energy technologies and energy efficient technologies, specifically solar water heaters. / text

Within the international context, energy has become a central factor in our everyday ways of life. There is increasing dependence on energy resources such as electricity to improve people quality of life. In developing countries, many people still do not have access to energy due to several challenges that have hindered infrastructural development and economic growth. At the same time, there is a growing interest in the protection of the environment and addressing issues of climate change. Green technologies such as solar water heaters are identified as technologies that meet the need of both its end-users and the environment through the provision of hot water. Access to 'hot water' is seen to be an important element resulting in an improved quality of life. In addition, several methods of heating water are explored to assess the attitudes and perceptions that people have towards solar water heaters. The dissertation involved in-depth interviews with residents from low income RDP houses in Kwandengezi Coffee Farm and government officials from eThekwini Municipality involved in the solar water heater programme for low income communities. The interviews revealed that renewable energy interventions such as the solar heater programme for low income communities contribute significantly to an improvement in people‘s quality of life. The availability of solar heaters allows people to enjoy hot water at a free cost, hence an improvement in the quality of life. The research further revealed that such renewable energy interventions can contribute to a reduction in negative environmental impacts, hence facilitating the acquisition of hot water with less dependence on electricity resources. / M.Dev.Studies University of KwaZulu-Natal, Durban 2013.

No description available.

Thesis (M.S.M.E)--Baylor University, 2009. / Includes bibliographical references (p. 133-134).

Η παρούσα διπλωματική εργασία έχει ως θέμα τον ευφυή έλεγχο μιας μηχανής Stirling χαμηλής θερμοκρασιακής διαφοράς, με στόχο την πρακτική εφαρμογή σε οικιακούς καταναλωτές για την παραγωγή ηλεκτρικής ενέργειας. Έγινε διασύνδεση μιας σειρά αισθητήρων (μέτρηση θερμοκρασίας) και επενεργητών (αντλίες) σε ένα πρωτότυπο σύστημα, έτσι ώστε να προσομοιωθεί κατά το καλύτερο δυνατό τρόπο η λειτουργία της αύξησης της θερμοκρασίας του υγρού σε ένα ηλιακό θερμοσίφωνα και της τυπικής οικιακής ημερήσιας κατανάλωσης. Με βάση αυτό το πρότυπο παραγωγής και κατανάλωσης ενέργειας διαμορφώθηκε ένας ευριστικός έλεγχος έτσι ώστε να παραχθεί η περισσότερη ηλεκτρική ενέργεια χωρίς να παραβιασθούν μία σειρά από περιορισμούς που αφορούν στην χρήση του ηλιακού θερμοσίφωνα. Πειραματικά αποτελέσματα επιβεβαιώνουν την αποτελεσματικότητα της μηχανής Stirling και την ανάγκη προσαρμοστικοτητας της λειτουργίας της έτσι ώστε να ανταποκρίνεται στις ιδιάζουσες ανάγκες της κάθε οικογένειας. / This thesis is on the intelligent control of a Stirling engine with a low temperature difference in order to practice residential consumers for electricity production. An interface of a series of sensors (temperature measurement) and actuators (pumps) became in a prototype system in order to simulate as best as possible the function of warming the liquid in a solar water heater and the standard daily household consumption. Under this model of production and consumption was a Heuristic control order to generate more electricity without having violated a number of restrictions on the use of solar water heater. Experimental results confirm the effectiveness of the Stirling engine and the need for adaptability of its operation to meet the specific needs of each family.

Orientador: João Francisco Escobedo / Banca: Dinival Martins / Banca: Alexandre Dal Pai / Banca: Erico Tadao Teramoto / Banca: Ricardo Molto Pereira / Resumo: O principal objetivo deste estudo é avaliar, com bases em resultados experimentais, um sistema de aquecimento solar constituído de mangueira de polietileno que permite a transferência do calor gerado pela radiação solar direta e/ou difusa (Energia Solar Térmica) para a água. O sistema foi dimensionado para atender a demanda de um Centro de Ressocialização com capacidade para 220 internos. Justifica-se a escolha do tema pelo fato de que consiste em um assunto atual de grande relevância, principalmente porque vive-se uma crise energética em nível mundial. O estudo comprova através de um experimento a viabilidade do aquecedor solar de baixo custo, considerando-se sua aplicabilidade em locais que demanda grande volume de água aquecida para banho. Os resultados demonstraram que o sistema alternativo proposto atendeu de forma eficiente e econômica a demanda solicitada, o que pode ser adotada pelo poder público em qualquer um de seus segmentos que necessite de água aquecida, com objetivo de reduzir custos e contribuir com o sistema energético brasileiro. O sistema foi analisado para atuar em fluxo continuo e fluxo intermitente, ambos objetivando aquecer a água a temperaturas superiores a 37 °C no inverno. Os resultados alcançados atenderam as expectativas coletando grandes volumes, com temperaturas médias acima de 42 °C. / Abstract: The aim of this study is to evaluate, with bases on experimental results, a solar heating system consists of polyethylene hose that allows the transfer of heat generated by direct solar radiation and / or diffuse (Solar Thermal Energy) to the water. The system has been designed to meet the demand of a Rehabilitation Center with a capacity for 220 inmates. Justified the choice of the theme for the fact that consists of a current subject of great importance, especially because it lives in an energy crisis worldwide. The study proves through an experiment the viability of solar heater low cost, considering their applicability in places that demand large volume of heated water for bathing. The results showed that the alternative system proposed met efficiently and economically the requested demand, which can be adopted by the government in any of its segments that need heated water, in order to reduce costs and contribute to the Brazilian energy system. The system was analyzed to operate in continuous flow, intermittent flow, both aiming at heating the water to temperatures above 37 °C in winter. The results achieved met the expectations collecting large volumes, with average temperatures above 42 °C. / Doutor

The nighttime losses from an integral collector storage (ICS) system were investigated. The significance of the sky temperature, wind speed, and ambient temperature on the losses were examined. Outdoor data was taken on several nights to characterize the thermal performance of an ICS system under various environmental conditions. Indoor tests were then performed under an artificial "nighttime sky" environment, with a simulated wind, in an attempt to duplicate the heat losses which occurred outdoors. The standard rating procedure which specifies the conditions for the heat loss tests for ICS systems was analyzed to see how well it characterizes the collector performance at night. Experimental results indicate a synergistic effect between the sky temperature and wind speed. The effects of wind on the losses from the ICS system overshadow the effects of small changes in sky temperature, but larger changes of sky temperature, with a constant wind speed, have a pronounced effect. It is recommended that both of these parameters be taken into account in heat loss tests in standard rating procedures. Indoor tests can duplicate outdoor heat loss results within 8 per cent. The minimum requirement for SRCC rating tests should be to monitor, record, and report the sky temperature. / M.S.