South Africa's electrical energy economy: environmental impacts,future developments and constraints

South Africa alone produces move than half of the electricity generated in the entire African continent. In spite of this about, half of South Africans are without electricity in their homes. South Africa's energy production and distribution patterns bear a striking resemblance to its overall economy-a heterogeneous intermingling of First and Third World characteristics. South Africa as a whole is responsible for about 2% of the world's greenhouse gas emissions although it has only 1% of the world's population. The normalisation and democratisation of the country will require enormous efforts to provide electricity, running water and education for the majority of the South Africans previously disadvantaged in the apartheid era. South Africa is trying to comply with the global demand for sustainable development by improving the technologies of its power plants, implementing renewable energy sources, improving efficiency of utilisation of electricity in industry and homes, adopting more efficient standards for electrical appliances, changing of the way of life etc. Although there are some constraints, the country is capable of overcoming these in the years ahead given the political will and proper international assistance     

Solar water heating potential in South Africa in dynamic energy market conditions

This paper is an attempt to determine the potential for solar water heating (SWH) in South Africa and the prospects for its implementation between 2010 and 2030. It outlines the energy market conditions, the energy requirements related to residential and commercial water heating in the country and the solar water heating market dynamics and challenges. It was estimated that 98% of the potential is in the residential sector and the rest in the commercial sector. The total thermal demand for 20 years for water heating was estimated to 2.2 EJ. A ‘Moderate SWH implementation’ will provide 0.83 EJ of clean energy until 2030 and estimated cost savings of 231 billion rand. For an ‘Accelerated SWH implementation’ these figures are 1.3 EJ and 369 billion rand. The estimated accumulated reduction of CO₂ emissions due to SWH can be as high as 297 Mt. The increased affordability of residential hot water due to SWH is an important social factor and solar water heating has a strong social effect.     

Using specially designed high-stiffness burnishing tool to achieve high-quality surface finish

This paper is focused on the process of ball burnishing. The influence of tool stiffness on surface roughness parameters was considered theoretically, while experimental investigation was conducted to establish the influence of initial surface roughness (previous machining) on the effects of ball burnishing as the finishing process. Experimental investigations were conducted over a wide interval of most influential process parameters (burnishing forces, burnishing feed, and number of burnishing passes). The material used in the experiments was aluminum alloy EN AW-6082 (AlMgSi1) T651. Burnishing was performed using a specially designed tool of high stiffness. Statistical analysis of experimental data revealed strong correlation between roughness, R _a, and burnishing force, burnishing feed, and number of passes for the three surfaces, each with different roughness parameters. Particular combinations of process parameters yielded very low surface roughness, R _a, equivalent to polishing. It is worth noting that high surface quality can be achieved with relatively small burnishing forces, which differs from the investigations published so far. Contrary to conventional approaches, which are based on elastic tool systems, the authors propose the burnishing process to be conducted with high-stiffness tools. Further investigation shall be focused on optimization of burnishing process parameters in order to achieve surface finish equivalent to high polish.     

Efficient and sustainable usage of electricity in South Africa: therole of the tertiary education institutions

South Africa's single electricity-generating utility ESKOM is considered to be the powerhouse of Africa. Proper industrial and residential demand-side management (DSM) of electricity usage could improve efficiency and contribute significantly to releasing spare generating capacity. South African tertiary education institutions have started energy-saving activities (the AfriCampus Collaboration) and work on energy conservation on their campuses. The various projects in the Collaboration's framework programme will result in a direct reduction in institutions' electricity bills