South Africa relies heavily on fossil fuels, particularly coal, to generate electricity and it is a well known fact that the use of fossil fuels contributes to climate change, as it produces greenhouse gases (GHGs). In fact, internationally South Africa is the 17th highest emitter of GHGs (Congressional Research Service (CRS), 2008). Coupled with the environmental consequences of fossil fuel use, South Africa has a further responsibility of addressing the inherited backlog of electricity provision to the rural, and previously disadvantaged communities. In an attempt to address these two problems, the government issued the White Paper on Renewable Energy. In this paper, renewable energy alternatives are proposed to replace a portion of traditional electricity generating methods. Concentrator photovoltaic (CPV) energy generation is one such renewable option available to government. CPV uses optic elements (such as lenses) to concentrate sunlight onto solar cells. Owing to the light being concentrated, the cells in CPV use less semiconductor material, which makes them more efficient in comparison to conventional photovoltaic (PV) cells. CPV is a technology that operates well in regions with high solar radiation. As such, South Africa is particularly well suited for this technology, with average solar radiation levels ranging from 4.5 to 6.5 05 ℎ/. CPV is also well suited for off-grid application, which addresses electricity demand in remote rural areas. This study is an economic project analysis of the installation, operation, maintenance, and decommissioning of CPV technology in a rural area in the Eastern Cape, South Africa. The study area chosen for this purpose is the Tyefu settlement in the Eastern Cape. Tyefu was deemed ideal for this type of analysis due to four characteristics. Firstly, Tyefu is a remote rural settlement at the end of the national grid. Secondly, the community is very poor and previously disadvantaged. Thirdly, many households are without Eskom generated electricity. Lastly, the study area is located in an area with ideal irradiance levels for CPV. Two methods of economic project analysis are applied to this case study, namely a costbenefit analysis (CBA) and a cost-effectiveness analysis (CEA). Additionally, two types of CBA are performed, namely a private CBA and a social CBA. The private CBA evaluates the Tyefu electrification project from a private investor's perspective and the social CBA evaluates the project from society's point of view. The CEAs carried out compare the costeffectiveness of the traditional PV technology to that of CPV in terms of private and social costs. The private costs and benefits of the CPV project were identified and valued in terms of market prices. Then, this cost benefit profile was used to calculate net benefits which in turn were discounted to present values using a private discount rate of 6.42 percent. Three decision making criteria were generated, namely the net present value (NPV), the internal rate of return (IRR) and the benefit cost ratio (BCR). Sensitivity analysis was carried out by varying the private discount rate and the bidding price. The social costs and benefits of the CPV project were identified and valued in terms of shadow prices. This cost benefit profile was used to calculate net benefits. The net benefits were discounted to present values using a composite social discount rate equal to 5.97 percent. The same decision making criteria used in the private CBA were used in the social CBA and a sensitivity analysis was completed by varying the social discount rate. In terms of the private CEA, the costs were identified and valued in terms of market prices. All costs were brought to present values using the private discount rate of 6.42 percent. In terms of the social CEA, the costs were identified and valued in terms of shadow prices. All costs were brought to present values using the social discount rate of 5.97 percent. The cost-effectiveness (CE) ratios calculated have identical denominators since the annual output for both technologies are identical - both CPV and PV systems deliver 30 300 kWh per annum. This output is based on the demand of the given case study. The private CBA showed unfavourable results. The private CBA has a NPV of R2 046 629.01, the IRR is undefined (this is due to no sign change being present in the cost benefit profile), and has a BCR of 0.365. However, the social CBA yielded positive results, with a NPV of R125 616.64, an IRR of 8 percent (which exceeds the social discount rate of 5.97 percent), and a BCR of 1.045. The CEA showed that the CPV is more cost-effective than the traditional PV both in terms of private and social costs. The private CE ratio of CPV is R4.23/kWh compared to PV's CE ratio of R4.39/kWh. Similarly, the social CE ratio of CPV is R3.51/kWh compared to PV's CE ratio of R3.69/kWh. CPV rollout appears to be socially efficient on a small scale according to the social CBA. Consequently, the CPV project is not seen as desirable in terms of the private CBA as the benefit (income received per kWh) in the private analysis is too small to outweigh the costs of implementing and running a CPV plant in Tyefu. On the other hand, a redeeming factor is that CPV may be feasible privately, for large scale applications. A major reason for the CPV project not being appealing to private investors is that the maximum bidding price of R2.85/kWh (as at August 2011) is not high enough for private investors to undertake the CPV project. The sensitivity analysis of the bidding price showed that the bidding price of R2.85/kWh needs to be increased in the range of 250 percent (R7.13/kWh) and 300 percent (R8.55/kWh) for a great enough incentive to exist for private investors. It is thus recommended that policymakers take this into consideration when formulating policy. In terms of the social CBA, it is recommended that government undertake CPV projects of this kind, as it will be a socially desirable allocation of resources. If government were to pursue these types of projects, it is recommended that CPV be implemented as it is more cost effective than PV.

Master of Engineering

Includes bibliography. / This report is aimed at evaluating the potential of alternative energy devices to satisfy the energy requirements of the underdeveloped rural regions of South Africa. A literature survey of the energy requirements of the inhabitants of such regions is first undertaken. Thereafter energy conversion devices using solar energy, wind energy, biogas, hydro energy, human energy and wood as their energy sources are evaluated according to their efficiency and "appropriateness" in supplying their energy needs. In each of the above categories a brief description of the energy source is given. Thereafter a survey of the typical village-scale energy conversion devices is given. It has been attempted to give at least one example of the more common devices and applications of each energy source. However, some subjective editing of the more expensive or impractical devices has been necessary. In each section, information is given on the availability of that particular energy resource in South Africa, and the potential of that resource to supply the rural energy needs is evaluated. Cost analyses are carried out, assuming funding by means of a 'soft' loan over the estimated life of an energy conversion device. Information covering many village-scale alternative energy devices has been assembled under one cover. It is hoped that this will guide those embarking on the development of alternative energy supply devices along the most appropriate path.

A research report submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science, Joannesburg, 2014. / An investigation was performed to look at a method to develop easy to use field survey measurements to assist decision makers in the process of deriving public protective actions. This method could be used at a nuclear power plant if certain accident conditions are known. International values for operational intervention levels (OIL’s) do exist and are recommended to be employed if station specific data has not been derived. No values exist specific to Koeberg Nuclear Power Station and as a result, this became an ideal opportunity to derive station specific values. It was firstly necessary to decide on a specific accident type and hence an applicable accident release fraction. A suitable accident software dispersion code was applied to calculate the organ doses for the selected accident type. It was also decided to use two different wind dispersion criteria to further refine the results. Due to the complexities of dose distribution within the body it was also necessary to look at the gamma dose in isolation as this would be the measurement radiation type utilised as a limit in the field either using installed radiation monitors or by physical measurement performed by station Radiation Protection staff. Comparisons were done with thyroid and lung dose versus gamma dose to arrive at ratios for this specific accident type. This would then be indicative of the total dose to each organ as a result of a single field measurement. Conclusions were drawn on the results obtained and recommendations were made for when this type of data may be suitable for use in the unlikely event of a nuclear accident.

Thesis: M.S., Massachusetts Institute of Technology, Department of Nuclear Engineering, 1979 / Bibliography: leaves 195-198. / M.S. / M.S. Massachusetts Institute of Technology, Department of Nuclear Engineering

No description available.

The objective of this paper is to investigate the feasibility of large scale electric power generation in the state of Florida by means of solar conversion. Such systems convert solar radiation directly to electricity or to thermal energy and subsequently to electricity. With the latter method, solar energy is initially collected and converted to heat at high temperature through a working fluid. The heat is then used to power conventional heat engine generator systems. Several methods have been proposed for converting sunlight to useful work. The most promising of these will be examined from a technological and economic viewpoint.

This thesis describes an adaptive protection scheme that performs the collection of the voltage and current phasors during post-fault period, tracking the power swing phenomena, identifying the onset of instability, and then issuing a stabilizing command. In this work, the protection system is to maintain the reliability! ensure the secure operation, and prevent total collapse of the power system. The work is based upon methods of clustering for meter placement in a bulk power system, and selecting the pilot points for installing the phasor measurement units (PMU) to measure the bus voltage phasors and associated branch current phasors. According to the network law, fast calculation of state estimation can be made from these measurements. Because the on-line assessment of transient stability has to provide a quick and approximate result, the direct method which determines stability without explicit integration techniques is applicable in this study. The results of the system stability prediction in real-time by digital computer simulation under stable and unstable operating conditions are presented. / Master of Science

A comprehensive stability analysis of a distributed power system (DPS) is performed. The possible performance degradation and stability problems caused by the loading effect of cascaded converters are analyzed. The effect of impedance overlap on the system and individual subsystems is examined. By applying the loop gain analysis technique, a forbidden region for the polar plot of the ratio of impedances at the interface between cascaded subsystems is determined. A method of transforming the forbidden region into a load impedance specification for a given source impedance is developed. The method guarantees system stability and minimal performance degradation of the DPS, while allowing impedance overlap at the interface. / Master of Science

The purpose of this research is to improve area Automatic Generation Control (AGC) by using the Multi-Pass Dynamic Programming developed in this research. The AGC of power systems coordinates the Load Frequency Control problem and the Economic Dispatch problem together to form a dynamic optimal control problem. A power system was partitioned into the Electric Power Network subsystem and the Mechanical Power Control subsystem. Earlier work has solved the Electric Network subsystem control problem, used analytical methods to find optimal trajectories and controls for the Mechanical Power Control subsystem, but only for the limited case of two generators. This research develops the multi-pass dynamic programming, checks convergence, derives the conditions for singular solutions and provides optimal control sequences and optimal trajectories for cases involving several generators. Parameter sensitivity is also studied here. Finally, some consideration is given to the comparison of multi-pass dynamic programming and conventional dynamic programming. / Master of Science