This research investigates the collection of concentrating solar energy and its transmission through optical fibres for use in high temperature applications such as lunar in-situ resource utilisation (ISRU) programmes, solar power generation and solar surgery. A prototype collector, known as the Fibre Optic Concentrating Utilisation System (FOCUS), has been developed and is capable of delivering high energy fluxes to a remote target. Salient performance results include flux concentrations approaching 1000 suns with an overall optical efficiency of 13%, measured from the inlet of the collector to the fibre outlet. The system comprises a novel solar concentrator designed to inject solar energy into a four metre long fibre optic cable for the transmission of light to the target. A nonimaging reflective lens in the form of a 600 mm diameter ring array concentrator was chosen for the collection of solar energy. Advantageous characteristics over the more common parabolic dish are its rearward focusing capacity and single stage reflection. The ring array comprises a nested set of paraboloidal elements constructed using composite material techniques to demonstrate a low-cost, effective fabrication process. At concentrator focus, a fibre optic cable of numerical aperture 0.37 is positioned to transport the highly concentrated energy away from the collector. The cable is treated to withstand UV exposure and high solar energy flux, and allows flexibility for target positioning. A computational analysis of the optical system was performed using ray tracing software, from which a predictive model of concentrator performance was developed to compare with experimental results. Performance testing of FOCUS was conducted using energy balance principles in conjunction with a flat plate calorimeter. Temperatures approaching 1500°C and flux levels in the region of 1800 suns were achieved before injection to the cable, demonstrating the optical system's suitability for use in high flux applications. During testing, peak temperatures exceeding 900°C were achieved at the remote target with a measured flux of 104 W/cm2 at the cable outlet. The predicted optical efficiency was 22%, indicating that further refinements to the ray trace model are necessary, specifically with regard to losses at the inlet to the cable. FOCUS was able to demonstrate its usefulness as a test bed for lunar in-situ resource utilisation technologies by successfully melting a lunar soil simulant. The system permits further terrestrial-based ISRU research, such as oxygen production from regolith and the fabrication of structural elements from lunar soil. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2011.

Increased standards of living and indoor comfort demands have led to an increase in the demand for air-conditioning in buildings in South Africa. Conventional vapor compression systems use refrigerants that damage the ozone layer and contribute significantly to the global warming effect. Therefore, there is an urgent need to implement environmentally cleaner ways of satisfying this air-conditioning demand and absorption cooling systems have shown great potential to do so. This project is concerned with finding the technical and economic effectiveness of solar powered absorption cooling systems for South African climatic conditions. Solar cooling systems are made up of a solar collector array, water storage tank, absorption chiller and cooling tower for heat rejection. In this study, two complete systems, one utilizing an open wet cooling tower and another using a dry cooler were studied and their technical and economical performance analyzed. One system was installed at Netcare Moot Hospital in Pretoria and comprised of a solar collector array made up of 52 evacuated tube collectors, two 6000 litre hot water storage tanks, 35kW LiBr-water absorption chiller, and a wet cooling tower. This system was coupled to an existing vapor compression chiller so that cooling is provided even when no solar energy is available. The installation controlled and remotely monitored through the internet and parameters logged through a Carel Building Management System. The other system is at Vodacom World in Midrand, Johannesburg and is an autonomous solar heating and cooling system aimed at maintaining the building environment at comfort conditions throughout the year. It is made up of a 116m2 evacuated tube collector array, a 6500litre hot water storage tank, 35kW LiBr-Water absorption chiller, 1m3 of cold water storage, a dry cooler for the chiller, and two underground rock storages to pre-cool the supply air to the building and the dry cooler respectively. Long term system performance studies were carried out by varying the system control strategy for the chiller, hot water storage tank, existing vapor compression chiller (in the case of the Moot Hospital installation), hot water storage tank, dry cooler (for the Vodacom installation) and the system Coefficient of Performances were calculated and life cycle cost analysis carried out. Due to the fact that solar availability and cooling demand are approximately in phase, solar powered absorption cooling presents a great opportunity for reducing peak electrical cooling energy demand. It was also discovered that the economic effectiveness of the system increases with the absorption chiller capacity, and it‟s more advisable to operate the solar absorption cooling system with a vapor compression chiller as a backup for facilities that require uninterrupted cooling. The solar autonomous system is oversized for most of the year since it is designed to cover the peak cooling loads. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2012.

In South Africa, a significant amount of electrical energy is used for air conditioning in commercial buildings, on account of the high humidity experienced. Due to its geographical location, the levels of solar irradiation and the demand for air-conditioning of commercial buildings reach maximum levels simultaneously. The South African region daily solar radiation average varies between 4.5 and 6.5 kWh/m2 and when compared to the United States 3.6 kWh/m2 and Europe’s 2.5 kWh/m2 , solar thermal powered cooling technologies has significant potential as this solar irradiation is also available all year around [1]. Utilizing solar energy for an air conditioning system has the advantage that the availability of solar radiation and the need for cooling reach maximum levels simultaneously and proportionally. This type of air conditioning system has an electrical energy saving benefit in light of increasing energy tariffs and the energy crisis currently facing Eskom in South Africa. Solar-assisted Absorption Cooling systems decreases the peak electricity consumption, is less noisy and vibration free, since it does not contain a compressor and this gives a higher reliability, low maintenance and its electricity consumption is approximately four times less (21.8kW versus 5.5kW for 35kW of Cooling) than that of an electric driven chiller containing a mechanical compressor [2]. However, due to the high capital cost of solar powered air-conditioning plants, it is essential that a feasibility analysis be undertaken to indicate and establish a return on capital investment. The main objective of the present study is to investigate and establish the feasibility of a solar-assisted air-conditioning system based on Lithium Bromide and Water (LiBr/H2O) absorption chillers on a medium scale for commercial buildings in terms of energy saving and performance. This study presents the results of the experiment on a solar-assisted air-conditioning facility constructed and installed in October 2009 at Pretoria’s Netcare Moot Hospital. This study has confirmed that a payback period of 13 months can be achieved and the performance parameters of the manufacturer’s specifications for a solar-assisted air conditioning system are exceeded for the South African climate. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2012.

The use of sunlight has always been a major goal in the design and operation of commercial buildings to minimize electrical consumption of artificial lighting systems. Glazing systems designed to allow optimal visible light transmission also allow significant unwanted direct solar heat gain caused by infrared light. Conversely, glazing systems that are designed to reflect unwanted direct solar heat gain significantly reduce the transmittance of visible light through windows. The goal of this research was to characterize the performance of water as gap-fill for double-glazing units in eliminating the compromises that exist in current glazing systems with respect to light and heat transmittance. An in situ test approach and computer simulations were conducted to measure the performance of water-filled glazing units against air-filled glazing units. The thermal transmittance and solar heat gain coefficient values obtained from both the field experiments and computer simulations, glazing units with air-fill proved better than the glazing units with non-flowing water-fill. However, the high convective coefficient and the high thermal mass of the water can be used to its advantage when it is allowed to flow at peak temperatures, thus, maintaining lower temperature swings indoor. This can lead to a reduction of about 50-70% direct solar heat and still maintain high visibility.

Access to modern energy is central to addressing important global development challenges including poverty, inequality, climate change, food security, health and education. The understanding of the concept of energy poverty is critical when making any attempts to alleviate it. Lack of access to sustainable energy is also a major factor preventing social and economic development, both of which are linked to sustainable poverty reduction. However, worldwide access to energy has shown very slow progress because of the costs associated with electric grid extensions and decentralized systems by which power is offered. This study investigates the viability of implementing solar energy in poor communities in Inanda, which is located in Durban, South Africa. Inanda is known to be an area with high unemployment and high poverty levels. Most important to this study are high energy poverty levels in the area. It was found that these communities prioritised energy for cooking, lighting and heating. The results of this study also indicate that in most households, multiple sources of unsustainable energy sources were being used. These included electricity, fuelwood, gas, paraffin and candles. Illegal electrical connections are a growing problem in this community, and other traditional sources were found to have numerous effects on human and environmental health. Upon investigation of the potential for renewable energy implementation in these communities, it found that there was a high willingness to use it, specifically solar energy; however, more education is needed regarding solar energy and related benefits. It was also indicated that the provision of sustainable energy will allow more time for income-generating activities in the community. The biggest challenge with regard to provision of solar energy was cost. These communities cannot afford to pay high start-up and maintenance costs for the technology. It is for this reason that efforts should be made to subsidize these costs and integrate this plan into policy-making. This will not only provide poor communities with sustainable energy, but also help advance the renewable energy industry in South Africa. / M.A. University of KwaZulu-Natal, Durban 2013.

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.

The solar concentration performance of a tracking, flat-base, line-focusing Fresnel mirror was investigated in this study. The Fresnel mirror consists of flat mirror strips situated on a base and oriented at appropriate angles to focus incident light to a desired line. Simple optical ray tracing and energy conservation were used to develop a mathematical model of the concentrator assuming small or zero diurnal tracking errors. The model analyzed the concentrator design and provided detailed expressions for the geometric evaluation of the concentrated sunlight rays in the focal plane above the mirror. The local concentration ratio and the geometric concentration ratio were introduced to describe the intensity profile in the focal plane and the average concentration of sunlight on a target absorber. Included in the model were losses of incident sunlight due to imperfect reflection, nonreflecting portions of the base, and blockage by adjacent mirror strips when imperfect tracking occurs.Based on the analytical model and using the Ada high level language, a computer program was written to simulate the concentrator. To facilitate performance comparisons, a baseline concentrator design was adopted. To study the effects of imperfect tracking, performance data were generated for small tracking errors up to approximately two and one-half degrees. The effects of design variations were studied by varying the concentrator focal length, strip width, and base width.Simulation results demonstrated that the concentration characteristics were highly sensitive to tracking error. Intensity profile shifts relative to the target caused the highest losses in intercepted sunlight.Design decisions were found to dramatically affect the concentration character- istics. For the baseline concentrator under perfect tracking conditions, an optimum focal length was identified. Except for the disadvantage of added costs, decreased strip widths was found to be a way to increase both the maximum and average concentration ratio for the absorber. Using smaller strip widths might, however, critically affect the energy intercepted by the target under imperfect tracking. Increasing the concentrator base width increased the total amount of power in the focal plane, with a higher maximum concentration ratio and additional tailing of the intensity profile. / Department of Physics and Astronomy

The purpose of this paper was to compile a nationwide survey by state, on legislation designed to protect access to solar energy. Brief summaries of the information received are included. Land use planning techniques and tools such as zoning and subdivision regulations, as well as special solar zones and planned unit developments have been discussed as they relate to protection of solar access and solar energy use. This paper has distinguished between two types of solar energy systems, active and passive, and associated problems with each.Primary concerns for the users of solar energy systems have been the availability of solar energy and its access to the collector's surface. Solar energy is environmentally safe, however, access to solar energy can be a limiting factor to its use. Solar access protection methods vary with location. The differences in needs between rural and urban areas have been discussed.Increasing solar technologies indicate the need for communities to regulate solar access through innovative legislation. This paper with brief introductions to solar energy access protection techniques, and the state-by-state survey was prepared so as to provide the reader with a basic understanding of solar access protection and act as a guide to access protection methods. / Department of Urban Planning

Solar road panels are a technology that have the ability to revolutionize the way that roads are built and how electricity is generated. Strong incentives towards sustainable solutions in both of these fields have led to the design of innovative, multifaceted solutions, of which solar road panels are one of the most recent entrants. This research presents some initial analysis into the design of solar road panels from the perspective of Canadian pavement engineering. The hypothesis of this research was as follows: A specially designed modular panel can be constructed to withstand the structural and environmental loads on Canadian pavement structures while simultaneously generating electricity through embedded photovoltaic cells. Through a process that covers the design, construction, and analysis of the structural elements of a solar road panel prototype, this research evaluated the impact that solar road panels can have for Canada???s pavement infrastructure. Specific elements researched include the material selection for such a panel, the flexural response of the composite structure, how the panel will interact with traditional pavement and geotechnical materials while in use, and the change in performance of transparent layer materials as they are subjected to freeze-thaw cycling and scaling. The research found that the initial prototype design included a two 10-mm tempered glass pane transparent layers with a 12.7-mm GPO-3 optical layer and 19.1-mm GPO-3 base layer. The concept being that the glass would provide the rigidity required to protect the fragile solar cells while the fiberglass laminate has demonstrated performance as a traffic-supporting material in adverse conditions. Testing of this structure found that the performance was easily duplicated through finite element analysis, given that the material properties were assumed to be more rigid than the averages for tempered glass and GPO-3. Further finite element analysis demonstrated that the prototype solar road panel would not fail through traditional fatiguing methods, and in all cases on concrete, asphalt, granular, and subgrade bases the panels improved the performance characteristics of the structural base. The environmental conditioning of acrylic, glass, and polycarbonate specimens demonstrated that glass is the ideal material choice for the transparent layer for Canadian solar road panels. It proved to have the greatest freeze-thaw and scaling resistance of the three materials, and while the friction characteristic of the flat glass samples would not be suitable for driving on, avenues of research were identified that could improve this characteristic. In summary, the research conducted clearly proved the hypothesis; it is possible to build a structure that can house a photovoltaic system while supporting the structural and environmental loads that Canadian pavement are exposed to. The ideal panel would be constructed with a tempered glass transparent layer, GPO-3 optical and base layers, and the structure would be installed on a concrete structural base. The refinement of this design will be the scope for future research.

Uppsala kommun has acquired the land at Ulleråkerand the plan is that it should be the starting point forthe new southeast district. The area is supposed toinclude 8000 new homes. The idea is also that the areashould be a new modern energy-efficient district. Thisreport examines how much energy that could be savedby using a passive house integrated design instead oftodays standard. Simulations in Matlab regarding localenergy utilization has also been done. Calculationsshow that the passive house integrated designgenerates in a total energy saving of 49 per centcompared to the standard house. The local electricalproduction comes from solar cell panels placed on theroofs and facades and the installed power is 19.8 MW.The production covers 80.3 per cent of the totalenergy demand or 91.4 per cent of the electricaldemand per year. But the systems production ismismatched to the local demand for electricity.