Scielo RSS <![CDATA[Journal of Energy in Southern Africa]]> vol. 20 num. 4 lang. es <![CDATA[SciELO Logo]]> <![CDATA[<b>The use of liquefied petroleum gas by South African low-income urban households: A case study</b>]]> At the end of 2005 and in 2006, the Western Cape suffered extended blackouts. The cuts came as a shock and customers were loud in their criticism of Eskom and the City of Cape Town's failure to provide a reliable electricity supply. The utility Eskom's responses included the introduction of an aggressive Demand Side Management (DSM) programme with the goal of saving electricity and reducing the need to shed customers. In Khayelitsha, Cape Town, the DSM programme entailed an exchange and subsidy programme: households were encouraged to swop their two-plate electric stoves for Liquid Petroleum Gas (LPG) stoves. This intervention is the subject of this paper. The results of the study were analysed in terms of the socio-economic characteristics of the sample interviewed, multiple fuel use and transition trends in households in urban areas, changes in behaviour in electricity and LPG use, changing perceptions of LPG and the impact of the intervention. Previous studies in household energy use showed that people perceived LPG to be dangerous saying that it posed a greater danger to the household than paraffin since it might explode. Surprisingly, during the electricity power cuts in 2006, people in low-income communities, readily accepted LPG stoves in great numbers and a year later, up to 89% of the households surveyed, reported still using LPG for cooking. <![CDATA[<b>Determination of regional emission factors for the power sector in Southern Africa</b>]]> The generation of power within Southern Africa is reviewed. A study is described in which the emission factors for CO2 and NOx were determined experimentally across a wide range of power stations and technologies, and compared to the IPCC default factors. It was found that the CO2 emission factors tended to be at the upper end of the IPCC default range, whereas the NOx emission factors were generally below the low end. The results from South Africa tend to dominate the regional picture at present, but this is likely to change in the near future, as Botswana has announced plans to introduce over 4 000 MWe of coal-fired power stations. <![CDATA[<b>An efficiency assessment analysis of a modified gravitational Pelton-wheel turbine</b>]]> A Pelton-wheel impulse turbine is a hydro mechanical energy conversion device which converts gravitational energy of elevated water into mechanical work. This mechanical work is converted into electrical energy by means of running an electrical generator. The kinetic energy of the Water-jet is directed tangentially at the buckets of a Pelton-wheel. The Water-jet strikes on each bucket's convex profile splitter and get split into two halves. Each half is turned backwards, almost through 180° relative to the bucket on a horizontal plane. Practically this angle may vary between 165° to 170°. Normally all the jet energy is used in propelling the rim of the bucket wheel. Invariably some jet water misses the bucket and passes onto the tail race without doing any useful work. This hydro device is a good source of hydro-electrical energy conversion for a high water head. The present work in this research paper deals with some advanced modifications in the conventional Pelton-wheel so that it can be used for low-head and heavy-discharge applications. Both kinetic and potential energy of the water source is consumed by the runner wheel. Considerable gravitational effect of the water jet is exploited by means of some modifications in a conventional Pelton-wheel. A comparatively heavy generator can be run by this modified Pelton-wheel turbine under low-head and heavy-discharge conditions. The modified features provide enough promising opportunities to use this turbine for Mini and Micro hydro power plants.