Scielo RSS <![CDATA[Journal of Energy in Southern Africa]]> vol. 21 num. 4 lang. es <![CDATA[SciELO Logo]]> <![CDATA[<b>The mapping of maximum annual energy yield azimuth and tilt angles for photovoltaic installations at all locations in South Africa</b>]]> Photovoltaic (PV) technology is fast emerging as a viable energy supply option in mitigation against environmental degradation through the burning of traditional fossil fuels. The cost of the technology, however, still poses a major challenge, as the efficiencies are generally still quite modest. Current research efforts to improve efficiency are mainly focused on component physics and manufacturing technologies. Little attention seems to be paid to improved system design at field level. Traditionally it is assumed that a panel installed at a tilt angle that is equal to the latitude at a location should achieve maximum annual energy yield for a non-tracking installation. However, in practice, due to a number of factors such as wind speed, wind direction, air temperature, global and diffuse irradiation and other climatic factors, the optimum azimuth and tilt get more convoluted. In this paper the optimum angles (azimuth and tilt) to maximise annual energy yield for fixed angle PV installations at all locations in South Africa have been tabulated. Climate data software together with solar design software were used in determining the angles. The availability of these tables will offer an additional support tool to the country in promoting the growth of PV as a viable alternative energy generation technology for both urban as well as the most secluded rural areas that are not grid connected. <![CDATA[<b>Assessing regulatory performance: The case of the Namibian electricity supply industry</b>]]> The power sector reforms that commenced in the 1990s led to the establishment of independent electricity regulators in more than twenty countries across Africa. The main purpose for these institutions was to create greater transparency in tariff setting and provide increased certainty for investors. At the same time regulators are charged with the protection of the interests of current and future consumers of electricity. During the initial stages of reform it was the expectation that the state owned incumbents that were traditionally vertically integrated would be unbundled and privatised. In practice there have been very few privatisations and what have emerged are hybrid markets where state-owned utilities remain dominant with independent power producers on the margin. In these markets regulation is a complex melting pot of incentivising the performance of state-owned utilities, attraction of private sector investment especially to fill gaps in generation capacity and making sensitive pricing decisions. Recognising that regulation is beginning to establish a track record, the African Electricity Regulator Peer Review and Learning Network, an initiative of the University of Cape Town, Graduate School of Business provides an opportunity for high level learning through the assessment of regulatory performance. We detail an assessment of regulation in Namibia where we find prices transitioning to cost reflectivity but question the sustainability of current arrangements in the distribution of electricity and the country's long-term generation adequacy. <![CDATA[<b>Life cycle inventories to assess value chains in the South African biofuels industry</b>]]> The South African government ratified a new biofuels industrial strategy at the end of 2007. The feasibility study that forms the basis of the strategy highlights the potential environmental implications of such a strategy. However, at present there is no structured approach to evaluate the environmental profile of the scenarios within the strategy. This paper introduces life cycle inventories whereby the environmental profiles of biofuel value chains may be evaluated meaningfully. The scope of the paper focuses on the seed extraction biodiesel production scenarios of the strategy. The inventory analysis shows that the inputs and outputs of the farming unit process are sensitive to the type of crop and region of produce. Water usage is a highly variable parameter, which emphasises the importance of rainfall and irrigation to the overall burden of the biodiesel system on water resources. Crop yields may differ by a factor of two, which is a significant difference in terms of land and non-renewable energy resources requirements. The oil and meal/cake content of the seed proves to be the most important parameter that influences the initial unit processes of the value chains; almost all the inputs and outputs of the farming unit processes, for all the crops, range in the order of a factor of two due to this parameter. The uncertainties associated with the logistic system in the value chain also have major implications. Further, should there be no market offset for the meal/cake co-products, the waste treatment requirements would be highly uncertain. Very little uncertainties were detected in the biodiesel production unit process, although the energy efficiency, and sustainability, of the overall production system remains questionable. The paper identifies a number of limitations with inventory sets that need to be addressed through further research efforts to improve the environmental evaluations of a biofuel value chain in South Africa for policy-making purposes. <![CDATA[<b>Bioenergy use and food preparation practices of two communities in the Eastern Cape Province of South Africa</b>]]> A study was undertaken in two communities that use firewood in the Keiskammahoek area of the Eastern Cape Province of South Africa to understand their behaviour with regard to energy use during food preparation as well as the extent of practising efficient cooking habits. The results showed that despite the high level of electrification, firewood was used in most households (> 60%) for cooking while electricity was mostly used (> 90%) for lighting. Firewood is also preferred for cooking food that takes a long time to prepare, while more convenient sources of energy such as electricity is used for short periods of cooking and re-heating of food. Secondary sources of energy used for cooking included paraffin, dung, leaves and twigs. The study found that there was some deliberate use of energy saving techniques in both communities, although limited and not necessarily practiced with a view to saving energy. Less than half of the respondents soaked hard grains and beans before cooking; while all of them cut food into smaller pieces before cooking commenced. A third of respondents had utensils ready before cooking commenced in one village while two thirds placed utensils and food together before they commenced food preparations in the other village. Pots were covered with lids and water was added in small amounts as required. The heat from fire was not monitored, but fires were extinguished after use. The greatest potential for improvement exists around cooking appliances; where all households were found to be using three-legged pots on open fires when cooking with biomass energy. Open fires are highly inefficient and the use of efficient biomass cook stoves would increase efficiency. It is recommended that in order to reduce the use of biomass-derived energy consumption and expenditure in low-income households, the use of multiple energy sources and portable energy efficient firewood stoves should be promoted. In addition, there should be an aggressive dissemination of information on further processing of fuelwood into forms that can easily be stored and used; and various forms of pre-treatment of hard foods.