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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.
71

User-performance sensitivity of small sunspaces in a Scottish housing context

Ho, Hin-Ming January 1995 (has links)
The performance of unheated solar buffer zones (SBZs) or sunspaces in relatively high latitudes' locations has become increasingly controversial. Conceived as simultaneously saving energy and providing amenity, the latter characteristic has provided the user with the opportunity and/or aspiration to negate the former - by heating a sunspace during winter either directly, or by opening it up as an extended heated part of the dwelling. Scotland has been host to passive solar projects promoting the use of small sunspaces where 'opening up' is a greater risk than directly heating. 'Opening-up' signals a change from 'indirect' to 'direct' solar gain with the heated volume partially extended. Within this context, this work examines the relevant aspects of a small sunspace as a passive solar technique by posing three questions from which answers are to be sought. 1. How useful and usable are the sunspaces ? 2. To what extent are occupants' interventions affecting energy saving ? 3. What is the energy 'worth' of the two sunspaces? The vehicle for this work is the CEC Solar Energy Demonstration Project at Easthall, Glasgow, where 36 thermally sub-standard flats built in the 1960s have been retrofitted with each flat having two sunspaces on opposite facades to tackle the issue of random orientation, and a common stairwell functioning as a shared thermal buffer space. The author's close acquaintanceship with a relatively large sample of occupants over a monitoring period of two years, taken in conjunction with data from questionnaires, interviews, diaries and personal observations, has enabled a substantive 'cause and effect' analysis. The findings confirm the likelihood of user intervention negating optimum performance, especially in spring and autumn, and in association with particular household types and characteristics. Nevertheless, the mean space heating load was approximately 30% lower than it would have been for the equivalent dwelling adjusted to the same internal temperature and ventilation rate, but without the front and rear sunspaces; and winter performance vindicates the role of sunspaces in providing good air quality at a relatively low running cost. The work sets aside the issue of life-cycle, pay-back analysis since, in general terms, this is dependent firstly on how much of the cost of sunspaces is written off as necessary floor area or improved amenity, and secondly on variable costs of a complementary energy-efficient package. However, on the assumption that these factors may be favourable, the work concludes with broad design recommendations based on the research findings; in particular recognising the dominance of the 'heat recovery' rather than 'solar' mode of operation of sunspaces.
72

Development of a roof integrated solar air collector

Belusko, Martin January 2005 (has links)
Solar heating systems are a proven technology which can significantly reduce the amount of fossil fuel needed to meet the heating reuqirements of homes. The southern part of Australia represents the region which requires considerable heating and experiences significant levels of sunshine during the winter period. However existing solar heating systems are not a viable technology due to practical, aesthetic and cost factors. A novel concept for a solar heating system has therefore been proposed which attempts to address these factors.
73

Solar energy for domestic use in southern Brazil

Hedenberg, Ola, Wallander, John January 2008 (has links)
<p>Almost all the domestic water in Brazil is heated with an electrical heater directly by the end consumer. A typical heater has an effect of 5 400 W and when the whole population takes a shower in the evening it causes big peaks in the electrical grid. This consumption peaks could be reduced by simple and cheap solar collector system. </p><p>Different system technologies and the most important parts of a solar collector system are described in the technical background. In Lajeado almost every system is a self-circulated system because of the simplicity and the lower costs. </p><p>Solar cooling as an alternative to the vapor compressor chillers has been studied. The cooling demand is biggest when the sun shines; this makes the sun perfect as a source to cooling. The ab- and adsorption chillers as a method in the future have been discussed in this paper; however it has only been studied briefly because small scale chillers using the technology can not be found on the market yet. </p><p>A number of different systems have been dimensioned after the existing conditions of Lajeado, the town where the project has been carried out in. Prizes and costs for both installation and materials come from the local solar collector supplier. With this as a background; several systems for various hot water demands has been dimensioned and costs and repayment time been calculated. A study of all the systems shows that, if the hot water demand increases and the systems get bigger, the profitability grows and the repayment time becomes shorter, down to three years. In almost every case the repayment time was under eight years, which makes solar heating attractive and the profit is good for the southern Brazil.</p>
74

Prospection of Swedish District Heating : the status of solar energy

Zeng, Yuming January 2013 (has links)
Due to the environment degradation and threats of the climate change, how to develop the technologies to use renewable energy and improve current energy systems to meet the increasing demand of human activities instead of using fossil fuels are amongst hot issues that being discussed nowadays. Due to the specific weather condition, district heating, which contains space heating and domestic hot water, is needed in Sweden. Solar energy is the most potential and environmental friendly energy resource. It can be utilized in many different aspects. The profitability of building solar heating plant for producing heat to supply the district heating in Sweden was discussed in the thesis. In order to achieve the result, central solar heating plant and solar combisystem were discussed. Information was collected from “Sciencedirect”, some related companies and institutions websites, and etc. Very few solar radiations are available during winter in Sweden, while the demands of district heating are the highest. During summer time, a lot of cities in Sweden can use the industrial waste heat to cover the district heating load, and in some cities where there is no industrial waste heat can operate biomass combined heat and power (CHP) plant to cover the heating load. Combined solar-biomass heating plant could improve the efficiency of biomass heating plant and reduce the unnecessary heat losses. Solar combisystem has a relatively high cost and complex system. The system which is able to supply some hot water for washing machine may have a good future, due to the possibility that the price of electricity in Sweden increases. Large-scale solar heating plants are less attractive in Sweden due to the existence of industrial waste heat and CHP plant that supplied by biomass. Combined solar-biomass heating plant would be a good system to build if there is no available industrial waste heat and biomass heating plant is used to supply the district heating. Due to the current electrical price and the cost of combisystem, it is not that attractive to build this system. In the coming future, if the transportation cost and the price of biomass itself become too high to make the CHP plant no longer cost effective, and the price of the electricity become high, the solar energy will make more contribution to the district heating in the coming future.
75

Simulation of solar selective absorbing coatings with needle optimization method and sputtering of simulated coatings.

Kobayashi, Hiroaki January 2012 (has links)
No description available.
76

Effects of incorporating renewable energy sources into the electricity grid

Sakib, Nazmus 08 June 2015 (has links)
With the increasing demand for energy throughout the world, the environment around us is getting severely affected. The conventional energy sources (coal, oil and gas) are unfortunately the biggest polluters of the environment. The aforementioned energy sources emit greenhouse gases like carbon dioxide and methane, which are responsible for global warming and ozone layer depletion. The only feasible answer to this problem is to reduce the use of the conventional energy sources and focus more on other energy sources. The renewable energy sources (solar, wind and hydro) have been present in nature, but the technology to harvest these energies have always been relatively expensive until recently. The biggest advantage of using renewable energy sources is the fact that these energy sources will never run out and they also do not pollute the environment as their more conventional counterparts. With more research being conducted into better ways of storing the power trapped from the renewable energy sources and the relative difficulty of obtaining the ever-depleting conventional energy sources, the future for renewable energy sources definitely looks better than at any time in the past
77

Investigation of an emulsion/dispersion solar thermal energy storage system

Cease, Michael Edwin January 1980 (has links)
No description available.
78

Harnessing solar energy via photocatalytic materials for chemical reactions

Ullah, Najeeb January 2013 (has links)
No description available.
79

Evaluation of a parabolic mirror type of solar boiler

Allais, David Charles January 1958 (has links)
No description available.
80

Solar energy for domestic use in southern Brazil

Hedenberg, Ola, Wallander, John January 2008 (has links)
Almost all the domestic water in Brazil is heated with an electrical heater directly by the end consumer. A typical heater has an effect of 5 400 W and when the whole population takes a shower in the evening it causes big peaks in the electrical grid. This consumption peaks could be reduced by simple and cheap solar collector system. Different system technologies and the most important parts of a solar collector system are described in the technical background. In Lajeado almost every system is a self-circulated system because of the simplicity and the lower costs. Solar cooling as an alternative to the vapor compressor chillers has been studied. The cooling demand is biggest when the sun shines; this makes the sun perfect as a source to cooling. The ab- and adsorption chillers as a method in the future have been discussed in this paper; however it has only been studied briefly because small scale chillers using the technology can not be found on the market yet. A number of different systems have been dimensioned after the existing conditions of Lajeado, the town where the project has been carried out in. Prizes and costs for both installation and materials come from the local solar collector supplier. With this as a background; several systems for various hot water demands has been dimensioned and costs and repayment time been calculated. A study of all the systems shows that, if the hot water demand increases and the systems get bigger, the profitability grows and the repayment time becomes shorter, down to three years. In almost every case the repayment time was under eight years, which makes solar heating attractive and the profit is good for the southern Brazil.

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