Scielo RSS <![CDATA[Journal of Energy in Southern Africa]]> http://www.scielo.org.za/rss.php?pid=1021-447X20110003&lang=es vol. 22 num. 3 lang. es <![CDATA[SciELO Logo]]> http://www.scielo.org.za/img/en/fbpelogp.gif http://www.scielo.org.za <![CDATA[<b>Dissemination of solar water heaters in South Africa</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1021-447X2011000300001&lng=es&nrm=iso&tlng=es Global concern over a looming energy crisis, water scarcity and man-made climate change are driving a huge demand for clean technologies, which focus on preserving the earth's resources. In South Africa, the economy is very energy-intensive with coal being the main national energy supply. In view of the growing depletion of fossil fuel, it is important for South Africa to adopt a more sustainable energy mix. This study examines the potential for widespread dissemination of solar water heaters (SWHs) in South Africa. Barriers and constraints to market expansion are analyzed to determine strategies for overcoming these barriers. It is found that payback period of a SWH is shorter than the life-span of the system itself, indicating that SWHs are economically viable even with low production cost of electricity and thus represent a profitable investment proposition for end users, manufacturers and distributors. However, the subsidy programs offered by the government of South Africa may not be sufficient to facilitate diffusion. This is attributed to the high initial capital cost of the system and low affordability of the majority of the South Africa population with low income. Alternative financing mechanisms are required. <![CDATA[<b>The challenges and potential options to meet the peak electricity demand in Mauritius</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1021-447X2011000300002&lng=es&nrm=iso&tlng=es This paper reviews the current challenges facing Mauritius in terms of meeting peak electricity demand. As a fast-developing island-economy with a very high population density, this is a crucial issue. The more so that it imports 80% of its energy requirements in terms of fossil fuels, relies significantly on tourism and needs to protect its fragile ecosystems. The nature of the peak electricity demand and its evolution is firstly analysed. Reference is made to past scenarios for electricity supply, the obstacles to their implementation and their relevance in terms of sustainability. The forecasts underpinning the latter scenarios are found to be over-estimated. Demand-Side Management projects are discussed and their potential to promote an alternative scenario based on revised forecasts are discussed. Hence a new Maurice He Durable (Mauritius Sustainable Island, MID) scenario is proposed in view of stabilising the peak demand, reducing the rate of increase of total electricity demand and making the capacity margin positive. The newly-devised scenario is not only more sustainable but also addresses several political and socio-economic issues to bring holistic win-win solutions. Institutional and regulatory reforms as well as a relevant Business Framework are also important in order to meet the challenges of MID. The new scenario relies only on existing technology with an excellent track-record and provides the transition to a more sustainable future. <![CDATA[<b>Outdoor testing of amorphous and crystalline silicon solar panels at Thohoyandou</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1021-447X2011000300003&lng=es&nrm=iso&tlng=es The use of solar panels is becoming one of the options for some of the rural communities in Limpopo Province, South Africa, to get electrical energy for their radio and television sets as the national grid may not reach them in the near future. Hence, dissemination of knowledge of how to use the solar devices and their maintenance is crucial for these communities. This will be possible only if there is appropriate information available for the potential end-users, installers and extension workers. With this in mind, an attempt has been made to evaluate the performance of an amorphous and a crystalline solar panel at our experimental site. Outdoor tests were conducted to measure solar radiation, open-circuit voltage, short circuit current, current-voltage (I-V) curve, fill-factor and conversion efficiency and hence to compare the performance of the two types of panels. It was found that both types give a satisfactory performance for the climate of this region. <![CDATA[<b>Renewable energy, poverty alleviation and developing nations: Evidence from Senegal</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1021-447X2011000300004&lng=es&nrm=iso&tlng=es The desire to increase energy access remains a strong driving force for poverty alleviation in rural areas of developing countries. The supply of modern energy facilitates the improvement of human living conditions and the productivity of sectors. It also contributes by reducing the time spent, mainly for women and children, in collecting biomass and therefore can provide an opportunity for an increase in the education level of children and for women empowerment. This paper shows how renewable energy facilitates the improvement of the standard of living in a Sahelian developing country of Senegal. Using a life-cycle-cost approach while integrating an assessment of the environmental externalities, I argue that in remote rural areas where grid-connection is non-existent, photovoltaic (PV) renewable technologies provide suitable solutions for delivering energy services although wind technology has been considered as well. In this framework, policies promoting the adoption of clean technologies in developing nations like Senegal could be considered as being the main components on the agenda of poverty reduction. <![CDATA[<b>The impact of health behaviour change intervention on indoor air pollution indicators in the rural North West Province, South Africa</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1021-447X2011000300005&lng=es&nrm=iso&tlng=es Indoor air pollution has been associated with a number of health outcomes including child lower respiratory infections such as pneumonia. Behavioural change has been promoted as a potential intervention strategy but very little evidence exists of the impact of such strategies on actual indoor air pollution indicators particularly in poor rural contexts. The aim of this study was to evaluate a community counselling intervention on stationary levels of PM10 and carbon monoxide (CO) as well as CO measured on children younger than five. Using a quasi-experimental design, baseline data was collected in an intervention (n=36) and a control (n=38) community; the intervention was implemented in the intervention community only; and follow-up data was collected one year later amongst the same households. Despite the fact that indoor air pollution was reduced in both communities, the intervention group performed significantly better than the control group when stratified by burning location. The net median reductions associated with the intervention were: PM10=57%, CO=31% and CO (child)=33% amongst households that burned indoor fires. The study provides tentative evidence that a health behaviour change is associated with reductions in child indoor air pollution exposure. The intervention is relatively inexpensive and easy to replicate. However, more powerful epidemiological studies are needed to determine the impact on health outcomes. <![CDATA[<b>Experimental study on heat and mass transfer for heating milk</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1021-447X2011000300006&lng=es&nrm=iso&tlng=es In this paper, an attempt has been made to estimate the convective heat transfer coefficient for sensible heating of milk in a stainless steel pot during khoa, made by traditional method. Various indoor experiments were performed for simulation of a developed thermal model for maximum evaporation by varying heat inputs from 240 watts to 420 watts. The experimental data was used to determine values of constants in the well known Nusselt expression by simple linear regression analysis and, consequently, convective heat transfer coefficients were determined. It is found that the convective heat transfer coefficients decrease with an increase in rate of heating. The experimental error in terms of percent uncertainty was also evaluated.