Scielo RSS <![CDATA[Journal of Energy in Southern Africa]]> http://www.scielo.org.za/rss.php?pid=1021-447X20110002&lang=es vol. 22 num. 2 lang. es <![CDATA[SciELO Logo]]> http://www.scielo.org.za/img/en/fbpelogp.gif http://www.scielo.org.za <![CDATA[<b>Carbon footprint of the University of Cape Town</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1021-447X2011000200001&lng=es&nrm=iso&tlng=es Since signing the Talloires Declaration in 1990, the University of Cape Town (UCT) has been striving to set an example of environmental responsibility by establishing environmentally sound policies and practices, and by developing curricula and research initiatives to support an environmentally sustainable future. One of the most recent efforts in this quest was the release of a Green Campus Action Plan for the University of Cape Town by the Properties and Services Department in 2008. While the Plan proposed a number of carbon emission mitigation interventions for the University, it also stressed the need to conduct a detailed and comprehensive carbon footprint analysis for the whole University. The aim of this analysis was to determine the carbon footprint of UCT, not only to give a tangible number with which the University's carbon sustainability level can be compared with other academic institutions, but also to provide the much needed baseline against which future mitigation efforts on the university campus can be measured. UCT's carbon footprint for the year 2007 was found to be about 83 400 tons CO2-eq, with campus energy consumption, Transportation and Goods and Services contributing about 81%, 18% and 1% the footprint respectively. Electricity consumption alone contributes about 80% of all the emissions associated with university activities. UCT's per-capita emissions for 2007 amount to about 4.0 tons CO2-eq emissions per student. For comparison only, South Africa's 2007 per capita emissions were estimated at 10.4 tons CO2-eq. In terms of energy consumption only, UCT's footprint is about 3.2 tons CO2-eq per student, higher than the National University of Lesotho's value of 0.1 and much lower than Massachusetts Institute of Technology's value of 33.1. <![CDATA[<b>Enhancing consumers' voluntary use of small-scale wind turbines to generate their own electricity in South Africa</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1021-447X2011000200002&lng=es&nrm=iso&tlng=es This paper investigates whether households and small businesses can voluntarily take advantage of the South Africa's substantial wind resources to produce their own power from small-scale wind turbines in a viable way. The viability of small-scale wind turbines used to displace electricity consumption from the grid is assessed by means of a financial analysis based on the internal rate of return method. The benefits of small-scale wind turbines output is valued at the grid power tariff which is saved rather than at the wind feed-in tariff rate. The analysis found the small-scale wind turbines to be robustly viable in locations with a mean annual wind speed of at least 8m/s, which is only a few of the windiest locations in South Africa. The competiveness of the wind turbines is seriously challenged by the relatively low coal-based electricity tariffs in South Africa. As such, the financial analysis also considers alternative scenarios where the turbines are supported by financial mechanisms, namely: a tariff subsidy; a capital subsidy and revenue from carbon credits. The analysis reveals that a tariff subsidy of between R1.00 and R1.60/kWh or a capital subsidy of between R25.95 and R32.330/kW or a carbon credit price of between R2.135 and R3.200 will be needed to boost the viability of consumer-based small-scale wind turbines in areas with a mean annual wind speed of at least 5m/s, which is considered to be above average. Thus, there is a need for subsidizing all producers of renewable energy including those who produce it for their own consumption as they equally contribute to renewable energy expansion in the country. A tariff subsidy is however likely to be met with both political and public resistance if it means that consumers have to cross-subsidize the tariff, while the significant funds required for capital subsidies might not be freely available. Carbon credit prices have yet to mature to the required high levels. Thus, the removal of distortionary support to coal-based electricity generation might be the only currently available alternative of enhancing viability of consumer-based small-scale wind turbines. <![CDATA[<b>Analysis of the performance profile of the NCERD thermosyphon solar water heater</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1021-447X2011000200003&lng=es&nrm=iso&tlng=es The work reported here is the performance profile of a thermosyphon solar water heater developed by the National Centre for Energy Research and Development (NCERD), University of Nigeria, Nsukka. The performance evaluation was based on the mathematical models that describe the test system and some measured experimental data. The effect of some of the design and operating parameters that have been shown to affect the system's performance was investigated. The parameters considered included the number of glazing covers, glazing cover thickness, tube spacing and the nature of absorber plate material. The performance results indicate that the test system has a maximum average daily collector efficiency of 0.658 and a mean system temperature of 81°C. The efficiency of the collector drops to an average seasonal value of 0.54 with a negligible variation across the three climatic seasons was covered in the study. With a tube spacing not exceeding 10 cm, the performance of the system is optimized irrespective of the nature of the absorber plate material. We found that the number of glazing covers affects the top-loss coefficient of the system depending on the type of absorber plate used. Multiple glazing shows a negligible contribution especially for low temperature application. The glazing cover thickness does not affect the performance of the system significantly. <![CDATA[<b>What contribution does the installation of solar water heaters make towards the alleviation of energy poverty in South Africa?</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1021-447X2011000200004&lng=es&nrm=iso&tlng=es The South African government has publicized plans to install one million solar water heaters in households throughout South Africa by the year 2014, with the goals of reducing strain on existing electricity resources, mitigating greenhouse gas emissions, creating employment and alleviating poverty. This paper examines two existing solar water heater installation projects with the aim of investigating the social contribution of the installation of solar water heaters in low-income households in South Africa. The Sustainable Urban Livelihoods approach (SULA) was adjusted to provide an analytical framework for the development of suitable indicators of social change in the context of renewable energies and energy poverty. Increases in household capital and the reduction of household vulnerability to shocks, stressors and seasonal variability as the result of solar water heater installation were investigated in projects in low-income housing developments in the cities of Cape Town and Port Elizabeth, South Africa. Data collected from paired household surveys (before and after installation) in over 600 households and qualitative information (Most Significant Change stories) show that the provision of a constant, cheap source of heated water contributed positively to the alleviation of energy poverty. Household capitals (categorised as Human, Social, Financial, Physical, Natural and Gender capital), including aspects such as health benefits and time and financial savings, were all positively effected by the installation of solar water heaters. In addition, improved energy security greatly reduced household vulnerability to shocks, stressors and seasonal variability. Comparison between the two projects revealed that the geographical setting (climatic conditions in particular), and the approach and strategies adopted by the implementers of the solar water heater installation project, greatly determine the extent to which benefits to the households are realised.