Includes bibliographical references. / The Elundini municipality, situated in the interior Eastern Cape of South Africa, as with many other municipalities with a large portion of rural inhabitants, is beset with the challenge of needing to provide clean drinking water to these far lying people in an efficient and cost effective manner. Due to the large distances between villages as well as from any town or major infrastructure, supplying water via traditional pipe networks is not feasible. Historically, groundwater has been the water source of choice and abstracted via the use of diesel powered borehole pumps. These pumps are however noisy, require constant maintenance and are associated with high running costs associated with the ever increasing price of fuel. Not only is the fuel expensive in itself, but it is also required to be transported long distance to the boreholes on a regular basis. This study then investigated how solar and wind powered borehole pumps compared with diesel powered options. This was done by assessing the natural resource potential of the region (wind and solar power) as well as the groundwater abstraction potential of a sample of villages. Notional solar, wind and diesel powered systems were then designed for each of the villages with each of their unique water supply requirements and then compared against one another with a life cycle cost analysis for each system being performed. The study found that, not unlike other similar studies in other regions of the world, that over their lifetime, wind and solar powered borehole pumps were cheaper than their diesel counterparts. This was especially true for solar powered options as the solar resource for the region is superior to that of wind. Although traditionally shunned due to high capital costs, solar powered pumps have been commercialized in recent years and are now only marginally more expensive than diesel options. Wind pump capital costs are still prohibitively high, although running and maintenance costs are low. For the Elundini municipality however, and its relatively poor wind resources, this would not be a recommended technology.

Incldes abstract. / Includes bibliographical references. / The production and use of biogas on a household scale is becoming more common. The biogas is mainly used for lighting and cooking. Since some households may already be using sophisticated gas appliances prior to investing in an anaerobic digester and might not wish to downgrade to relatively simple and robust biogas appliances, a need to investigate the compatibility of biogas with a standard household appliance was identified. A gas hob was chosen.

Includes abstract. / This global review of concentrating solar power (CSP) technologies is based mainly on an assessment of available international literature, up to 31 October 2011. It includes a review of major CSP projects currently operating or under development at this time; the respective CSP technologies employed; and an assessment of the present and future economics of CSP relative to other conventional and renewable energy electricity-generating technologies. Global outlook scenarios for CSP are discussed, as well as specific conditions and proposals for CSP developments in South Africa. The economic analysis has been limited by several challenges. Since the CSP industry is new, there are few well-documented projects on which to base the analysis. Most of the projects referenced here are from the USA and Spain. As the CSP market rapidly expands, competition in the industry tends to restrict the disclosure of detailed financial/economic information for projects under development. In general, it has been difficult to compare the publicly available economic data, on a reliable basis, since the financial costing parameters used may vary from case to case. In addition, most of the economic forecasts, which have been reviewed, are based on forward modeling rather than practical proven costs. There are uncertainties and quite wide variations in such predictions. This dissertation concludes, however, that there is great optimism for the growing employment of CSP technology in the near future and that CSP electricity-generating costs, in areas with high solar energy resources, are expected to become competitive with levelised electricity generating costs from other conventional and renewable energy technologies. The cost reduction potentials for CSP lie mainly in expected technical research and development advances, and production economies of scale, achieved by high volume deployment, supported by mid-term investment incentives from governments and other agencies. Another cost reduction potential, especially in the South African context, lies in the localization of skills and local fabrication of some plant structures and components.

Includes bibliographical references. / Renewable energy sources such as wind energy for electric power supply are receiving serious consideration around the world due to global environmental concerns associated with conventional generation and depleted conventional energy resources to meet increasing electricity demand. This is more than evident in South Africa, where the recently launched Renewable Energy Independent Procurement Program (REIPPPP) has a proposed capacity of 3725MW, allocating 1850MW to wind energy. This dissertation investigates the effects that geographical dispersion and penetration level have on the wind capacity credit and the reliability of the South African power generation system, by estimating the capacity credit. Some of the estimates are tested using a simplified dispatch model, which is also used to estimate other indicators such as the expected energy not served and CO2 emissions of the system for different wind configurations. The sensitivity of the capacity credit definition is further investigated through two definitions. Several scenarios are used to investigate the capacity credit of wind generation, based on the updated IRP base case scenario.

South Africa has been facing challenges in both its energy and water sectors over the past few years. They are heavily dependent on each other and a better understanding of the linkages between the two sectors is crucial for sustainable development and planning in both sectors. While the water-energy nexus has been widely explored in developed countries, there is a limited amount of literature found on the significance of the nexus in South Africa. With the current critical drought in the region, alternative water sources are being considered by the City of Cape Town including seawater desalination, water re-use and abstraction of groundwater, to increase potable water supplies. The Cape Flats Aquifer represents a significant water resource for Cape Town and its yield can be further augmented by using artificial recharge with stormwater. Due to the location and water quality of the resource, several possible approaches have been identified for its exploitation. This study investigates quantitatively the energy implications of the three selected approaches in order to exploit the Cape Flats Aquifer as an alternative water source for Cape Town and further provides the potential carbon emissions from their respective energy usages. The three approaches consist of a Centralised Approach to treat the abstracted water for potable uses at two existing Water Treatment Plants (Blackheath and Faure); a Decentralised Approach to supply neighbouring suburbs with minimally treated water for non-potable uses through four proposed treatment plants and a Desalination Approach to treat brackish groundwater to potable quality at a proposed desalination plant. The energy implications of the approaches were evaluated using both direct energy usage during the abstraction, conveyance and treatment stages and the embodied energy of the consumables used during the treatment processes. These were then used to compare the shares of direct electricity intensities and embodied energy intensities of the alternatives at each stage to determine their viability. The individual stages' and overall energy intensities were quantified in form of the total energy required to produce a kl of treated water. The minimum energy required to abstract and convey the water was estimated using basic hydraulic principles. The energy usage at treatment plant levels was computed using the installed electrical capacities at the two existing water treatments for the Centralised Approach while the Decentralised Approach's demand was estimated by determining the treatment processes required to produce non-potable water, which is fit for usage. Energy requirements at the desalination plant were estimated using the salinity levels of the brackish groundwater and target salinity concentration of the treated water. The energy intensities of the approaches were then used as a basis to calculate the current and future electricity costs and their associated carbon footprints using the CSIR (2016) least cost scenario and the IRP (2016) base case future electricity mixes, as the higher and lower threshold for electricity generation costs and carbon emissions. The study found that the electricity intensities of all three alternatives depended significantly on the spatial layout of their respective systems, that is, the topography, distance and extent of their transmission networks. However, the embodied energy intensity of the Centralised alternative was found to be comparable to its electricity intensity, since more chemicals were to purify the water to potable levels. The Decentralised Approach's extensive pumped transmission networks contributed the most to its electricity intensity during the treatment process. The Desalination option was found to be the most energy intensive alternative, with energy intensities ranging from 7.41 to 9.62 MJ/kl, of all three options (1.16 to 1.57 MJ/kl for the Centralised Approach and 3.57 to 7.31 MJ/kl for the Decentralised Approach) and had the highest costs and emissions intensities, mostly caused by the country's coal intensive electricity mix. The Centralised option was found to be the least energy and carbon intensive of the three options and the most viable approach investigated. Desalination, nonetheless, can still considered as an alternative, given the issue of water scarcity, to increase water supplies. Despite its high energy demands, its carbon footprint could potentially decrease with a larger uptake of renewable energy technologies as sources of electricity. The importance of holistic planning across sectors was brought out quantitatively by using current and future water and energy mixes, providing valuable insights on the water-energy nexus, in this study.

Due to lack of generation capacity and high energy intensities South Africa's electricity supplier is forced to shut down high energy users frequently. Power cuts as well as escalating electricity prices threaten the country's steel industry. The objective of this study was to identify cost-effective energy efficiency improvements for the South African foundry industry. A lack of research in South African foundries was identified as existing literature on the topic was analysed. A large foundry operating an induction furnace in the Western Cape served as subjects to investigate the topic specifically in South Africa. The aim was to identify the energy intensity, evaluate already implemented energy efficiency measures and identify further opportunities to reduce energy cost of the foundry. The method followed for the data collection was much orientated on an industry energy audit. Types of energy, amounts and cost of energy usage were determined. The energy consumption and energy intensity of the foundry were analysed, based on meter readings, electricity bills and where necessarily a "bottom-up" approach for estimation was used. Results of the energy audit have shown that the foundry under review consumes about 127,000 MWh annually with a maximum demand of 26,500 kVA. The already implemented energy saving measures decreased the company's energy usage by 5% resulting in a current energy intensity of 1,493ZAR/ton. Further proposed energy efficiency measures included the compressed air system, preheating of the charge material and the reduction of the holding furnaces were analysed. The results of all evaluated measures, namely lighting, load-shifting and maximum demand management were cost effective solutions. Furthermore the recommended energy efficiency measures, namely reduction of compressed air leaks, reduction of holding furnaces as well as preheating of charge material, showed in theoretical calculations a reduction of carbon emissions as well as cost savings. This study offers an insightful view on energy intensity and energy efficiency opportunities in South African foundries, especially the ones operating an induction furnace.

Includes bibliographical references. / A case study was thus carried out at an applicable local industry (brewery) to assess the feasibility of implementing the heat pump for waste heat recovery. Through analysis, the focus was narrowed down from a site wide audit, to a departmental breakdown and then eventually to a specific process; the wort boiler. Three different alternatives were investigated and the performance and economic viability compared; a simple waste heat recovery solution involving a vapour condenser (vq, a mechanical vapour recompression (MVR) heat pump and a thermal vapour recompression (TVR) heat pump. It was found that the MVR system yielded the greatest energy savings, followed by the VC and then the TVR system. All three systems had positive rates of return, with the VC and TVR systems being tied for first place.

The Energy Research Centre (ERC), a research centre located at the University of Cape Town (UCT), is considering retrofitting its offices with measures to improve its occupants' thermal comfort, particularly during Cape Town's summer months. While a simple solution would be to install an active cooling system, first consideration should be given to the deployment of preventative cooling measures and retrofits. By these means, the costs of an active cooling system would be reduced, as well as the building's relative increase in energy consumption and indirect greenhouse gas emissions. This dissertation examines internal thermal conditions of the ERC under current building conditions and predicts levels of thermal discomfort likely to be experienced by occupants, with emphasis on Cape Town's summer season. Heat gain components to the ERC are quantified, and a Base Case cooling scenario is determined; this characterises the peak cooling load and active annual cooling energy required to alleviate summer thermal discomfort, if no other interventions are implemented. Thereafter, the impacts of a selection of preventative cooling measures on the Base Case cooling scenario are assessed, and a theoretical payback period for each progressive measure is evaluated, relative to projected installation and operational costs of an active system designed to meet the Base Case. A model of the ERC offices is developed in DesignBuilder, which characterises thermal properties of the building envelope, thermal loads of lighting, electronic equipment and building occupants, and effects of prevailing weather patterns and solar radiation at the site of the building. Physical energy simulations of the model are run in EnergyPlus, which uses a series of algorithms based on the Heat Balance Method to quantify internal psychrometric conditions and heat gains in half-hourly iterations. An EnergyPlus Ideal Loads Air System component is input into the simulation to quantify the active cooling load required to maintain comfortable design conditions. The results indicate that 7 814.5 hours of thermal discomfort are experienced annually across the ERC (divided into eight thermal zones in the DesignBuilder model), with 37.6% of discomfort hours occurring between December and March, and 12.8% in February alone. Notably, a greater proportion of discomfort hours, 38.9%, were predicted for winter months (June through August). However winter thermal discomfort was not addressed in detail here, as the scope of the dissertation was limited to analysing ERC cooling only. Solar gains through external windows were found to be the largest single source of annual heat gain (20.65 MWhth), followed by heat gains due to lighting heat emissions (19.99 MWhth). Profiles during typical summer conditions showed significant heat gain also arises from conduction through the ceiling, due to existing but sporadic and thin layers of fibreglass ceiling insulation, with gaps that allow thermal bridging between the roof space and ERC thermal zones. The Base Case annual cooling requirements were determined to be 27.64 MWhth, while peak cooling load was found to be 66.87 kWth. Sensible cooling dominated total cooling loads in summer months. East and west facing thermal zones required the greatest cooling energy (normalised per floor area), having been shown to experience the greatest normalised solar and lighting heat gains. Inclusion of a 75 mm polyester fibre insulation layer above the ceiling boards would result in a 13.6% decrease in annual discomfort hours, relative to the current building condition, and reduced peak cooling load by 19% relative to the Base Case. Increasing thickness above 75 mm resulted in increased ceiling thermal resistance and further reduced annual discomfort hours. However, the marginal improvements in thermal comfort were found to decrease with increased insulation thickness. A 75 mm thickness of polyester fibre insulation was therefore selected as the first preventative measure to be considered for the ERC, and was included in all further assessment of additional preventative options. Lighting retrofits were also considered, by means of two progressive measures: Delamping – the removal of fluorescent luminaires from overly lit thermal zones – and Relamping – replacement of remaining fluorescents and light fixtures with more energy efficient technology (as well as the Delamping and Insulation measures). Delamping was found, from simulation analysis, to reduce lighting heat gains by 31%, relative to the Base Case and annual cooling requirements by 24%, with total projected costs after 10 years reduced by 15.6% relative to the Base Case. Relamping had a less pronounced impact on cooling requirements, but resulted in 15 % lower lighting energy use compared to Delamping only. The final measure considered was a Shading measure, whereby the replacement of the existing solar window film, currently fitted to each of the ERC's external windows, with internal adjustable shading. The Shading retrofit (in addition to all previous preventative measures) was found to cause a 35% reduction in annual cooling energy relative to the Base Case, as well as a 7% relative to the Relamping scenario. However, cost evaluation showed that costs of implementing the Shading retrofit significantly outweighed net incremental annual savings achieved under the measure, and was thus not recommended as a preventative option for the ERC. Alternative shading options, such as fixed external shading, may prove more cost effective in mitigating the ERC's solar heat gains, and should be considered in further research. From these results, it was concluded that a combination of insulation and lighting upgrades would provide the greatest benefit, in terms of thermal comfort, to the ERC, and would result in a more cost effective active cooling system, should one be proposed. The dissertation ended with recommendations for further work, including further analysis of ERC heating requirements in winter, and investigation into additional and alternative cooling methods, such as passive or solar cooling.

Includes bibliographical references. / This study has explored a range of barriers, drivers and opportunities to improving energy performance in the South African crude oil refining industry, thus providing information to further support energy efficiency improvement efforts. Energy efficiency is a cost effective means of reducing greenhouse gas emissions and energy costs, bringing additional quality and production benefits.

This dissertation comprises a two-part study concerned with the identification and quantification of potential Concentrating Solar Power (CSP) sites in South Africa; and the performance and cost modelling, optimisation and analysis of two CSP technologies in three locations. A further theme of the study is the consideration of the availability of water for plant cooling purposes, and hence the comparison between, and analysis of optimal CSP technologies and cooling methods for each location.