Scielo RSS <![CDATA[Journal of Energy in Southern Africa]]> http://www.scielo.org.za/rss.php?pid=1021-447X20170001&lang=pt vol. 28 num. 1 lang. pt <![CDATA[SciELO Logo]]> http://www.scielo.org.za/img/en/fbpelogp.gif http://www.scielo.org.za <![CDATA[<b>Implications of biofuel production in the Western Cape province, South Africa: A system dynamics modelling approach</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1021-447X2017000100001&lng=pt&nrm=iso&tlng=pt The national government instated a mandatory blending policy to facilitate the uptake and establishment of a biofuels sector in South Africa. Uncertainty exists, however, regarding the implications and effects of producing biofuels within the Western Cape province, as part of a strategy of the province to transition to a green economy. This investigation was carried out as an effort to simulate the biofuel production within the Western Cape under certain project and policy considerations. A system dynamics model was developed to identify key strategic intervention points that could strengthen the business case of biofuel production. The model showed a feasible business case for bioethanol production, with the best case showing an internal rate of return of 23% (without government subsidy), and an emissions reduction of 63% when compared with coal. It is recommended that special consideration be given to the location of bioethanol production facilities, as operational costs can be minimised by incorporating invasive alien land-clearing schemes as part of the bioethanol production. The model further showed that medium-to-large-scale biodiesel production in the province is not feasible under the given model assumptions, as the positive effects of local biodiesel production do not justify the required government subsidy of ZAR 4.30 per litre. It is recommended that a different approach be investigated, where multiple on-site small-scale biodiesel production facilities are used, thus utilising multiple feedstock options and minimising capital expenditure. <![CDATA[<b>Public participation in technological innovation: The case of the Tshulu stove development programme</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1021-447X2017000100002&lng=pt&nrm=iso&tlng=pt The design of products for developing communities often excludes the end-users in the decision making process. The study aims to investigate public participation and engagement in the design and development of the Tshulu woodstove. Results of this research point to the need for improved communication between citizens and technical experts, as well as for narrowing the gap between the designer and the user by encouraging meaningful engagement and inclusion. Bottom-up approaches ensure sustained participation of the public, in turn increasing a sense of ownership in the product. These results have implications for energy policy and improved cookstove programmes for developing communities. <![CDATA[<b>Driving forces for fuelwood use in households in the Thulamela municipality, South Africa</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1021-447X2017000100003&lng=pt&nrm=iso&tlng=pt Energy is a fundamental requirement to sustain human life, but most people in rural areas do not have enough access to efficient and affordable energy resources. Socio-economic measures are increasingly used to determine household energy consumption patterns. The pattern of household energy consumption represents the status of welfare as well as the stage of a country's economic development. Household energy consumption is expected to increase in the future, along with growth in the economy and a rise in per capita incomes. This study was undertaken to understand the driving forces for energy preference in rural households, while reassessing the energy ladder and multiple fuel use. Two hundred questionnaires were administered to elicit information from respondents in Altein, Botsoleni, Makhovha and Thenzheni in the Thulamela municipality of South Africa. A non-parametric test (Chi-square) was used to determine the relationships amongst the factors influencing the use of fuelwood in the study area. Cramer's V was used to test the association of the variables, the strength and the direction of the relationship. The results indicate that household income, educational level and employment status, cultural norms and values, are among the key determinants of the energy preference scale. <![CDATA[<b>Learning from the literature on community development for the implementation of community renewables in South Africa</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1021-447X2017000100004&lng=pt&nrm=iso&tlng=pt Implementation of large-scale wind, solar and hydro projects in South African communities is intended to contribute to local economic development. Government policy, through the Renewable Energy Independent Power Producer Procurement Programme (REIPPPP), obliges energy companies to share revenue and ownership with local communities, thus providing renewable energy companies with a significant opportunity to position the industry as a significant contributor to community development and thus to the country's transformation and development agenda. This investigation draws on policy documents and interview data to establish that the policy's lack of appreciation for existing community development tradition and frameworks, commonly applied in South African development policy and programmes, has weakened its potential. Furthermore, it theoretically positions the emerging practice employed by the renewables industry in the implementation of the REIPPPP requirements, and outlines how existing academic and practical knowledge about community development and companycommunity relations can provide guidance and support in building an impactful practice. Highlights • South Africa is implementing a unique version of pro-poor renewable energy policy. • Industry and local communities and government need to build quality relationships to successfully implement the policy requirements. • The policy and practice ignores established community development traditions and frameworks. • Existing knowledge grounded in South African practice and policy experience can guide the sector's understanding of and vision for development. <![CDATA[<b>Policy perspectives on expanding cogeneration from bagasse in Malawi</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1021-447X2017000100005&lng=pt&nrm=iso&tlng=pt Agro-industries have the potential to make a substantial contribution to sustainable energy supply in Africa, including energy access in rural areas. This paper focuses on the drivers and barriers to wider use of cogeneration from sugarcane bagasse in Malawi as there is a potential for the technology to enable access to electricity in rural areas. The paper gives an overview of the policy landscape for the energy sector and the sugar industry in Malawi. The research involved site visits, focus group discussions, and individual semi-structured interviews with participants from key government departments, businesses, research institutes and international agencies. It was found that energy sector reform, the proposed feed-in tariff for renewable energy, and risk are the key issues for investment in this area. <![CDATA[<b>The role of energy in development</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1021-447X2017000100006&lng=pt&nrm=iso&tlng=pt Using World Bank Development Indicators, it is shown that the use of energy is strongly related to almost every conceivable aspect of development. Wealth, health, nutrition, water, infrastructure, education, even life expectancy itself, are strongly and significantly related to the consumption of energy per capita. In general, the approach taken was to break the consumption of energy into three or more classes, to calculate the average value of the relevant indicator in each class, and to demonstrate that the average value in one class was statistically different, at above the 95% confidence level, from the average in adjacent classes. In the case of life expectancy, the change in expectancy was tracked against energy consumption over 40 or more years, in India, China, Indonesia and Brazil. It is concluded that energy is such a necessary element in development that it should be seen as a basic right. The impact of energy on development is felt strongly up to about 2 000 kg oil equivalent per capita, and is essentially saturated above that level. The data are qualitatively assessed using the environmental Kuznets curve. The OECD nations appear to have peaked, and emissions may continue to drop for the foreseeable future. However, emissions from the non-OECD nations have surged in this millennium, and are likely to exceed 40 000 Mt CO2 per annum before slowing. In this light, the intent of the Paris Agreement to constrain global temperature rise to less than 1.5 °C, seems unrealistic. Any hopes of reducing carbon dioxide emissions significantly, in the face of development by the developing nations, seems doomed to failure. Highlights • Many development indicators are strongly related to the per-capita energy consumption. • The impacts of increasing energy on development continues up to about 2000 kg oil equivalent per capita per year. • Over the past 50 years, increases in per-capita energy consumption correlate strongly with increases in life expectancy. • If all developing nations strive for 2000 kg per capita per year energy consumption, CO2 emissions will continue to rise. <![CDATA[<b>The success of multi-sector participation in the management of revenue for beneficiary communities of South African renewable energy companies - sub-model A</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1021-447X2017000100007&lng=pt&nrm=iso&tlng=pt Multi-sector participation is one of three sub-models that resulted from the splitting of the original model that resulted from the data analysis as part of a thesis entitled Ά theoretical for successful management of revenue for beneficiary communities of renewable energy companies in South Africa.' The submodel provides specific guidance for the multi-sector participation of enterprises, stakeholders, industry experts and community development practitioners in the renewable energy sector to create a proactive, effective, and relevant decision-making process for achieving success in the management of revenue for beneficiary communities. To address the primary objective, a number of secondary objectives were formulated through the development of a conceptual model consisting of identified variables based on a comprehensive survey of the related literature. By constructing a path diagram between the independent variable and subsequent intervening and dependent variables, appropriate hypotheses were developed. Primary data sourced from an identified national and international population of community management practitioners were collected using an electronic measuring instrument. These data were analysed and tested empirically using structural equation modelling. The determinants that were identified through a review of the literature as elements of multi-sector participation that influences the success of revenue management for beneficiary communities for South African renewable energy companies included the use of outside advice, financial management, support services, and good governance. <![CDATA[<b>Modelling and testing a passive night-sky radiation system</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1021-447X2017000100008&lng=pt&nrm=iso&tlng=pt The as-built and tested passive night-sky radiation cooling/heating system considered in this investigation consists of a radiation panel, a cold water storage tank, a hot water storage tank, a room and the interconnecting pipework. The stored cold water can be used to cool a room during the day, particularly in summer. A theoretical time-dependent thermal performance model was also developed and compared with the experimental results and it is shown that the theoretical simulation model captures the experimental system performance to within a reasonable degree of accuracy. A natural circulation experimental set-up was constructed and subsequently used to show that under local (Stellenbosch, South Africa) conditions the typical heat-removal rate from the water in the tank is 55 W/m² of radiating panel during the night; during the day the water in the hot water-storage tank was heated from 24 °C to 62 °C at a rate of 96 W/m². The system was also able to cool the room at a rate of 120 W/m³. The results thus confirmed that it is entirely plausible to design an entirely passive system, that is, without the use of any moving mechanical equipment such as pumps and active controls, for both room-cooling and water-heating. It is thus concluded that a passive night-sky radiation cooling/heating system is a viable energy-saving option and that the theoretical simulation, as presented, can be used with confidence as an energy-saving system design and evaluation tool. HIGHLIGHTS: • Passively driven renewable energy heating and cooling systems are considered. • Time-dependent mathematical simulation model is presented. • Experimental buoyancy-driven heating and cooling system built and tested. • Experimental results demonstrate the applicability of the theoretical simulation model. • Saving and evaluation design tool. <![CDATA[<b>Quantifying South Africa's sulphur dioxide emission efficiency in coal-powered electricity generation by fitting the three-parameter log-logistic distribution</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1021-447X2017000100009&lng=pt&nrm=iso&tlng=pt This paper fits the three-parameter log-logistic (3LL) distribution to sulphur dioxide (SO2) monthly emissions in kilograms per gigawatt hour (kg/GWh) and in milligrams per cubic nano metre (mg/Nm³), at 13 of Eskom's coal fired power-generating stations in South Africa. The aim is to quantify and describe the emission of sulphur dioxide at these stations using a statistical distribution, and to also estimate the probabilities of extreme emissions and exceedances (emissions above a certain threshold). Using the 3LL distribution is proposed as such a distribution. The log-logistic distribution is a special form of a Burr-type distribution. Various goodness-of-fit measures, including the Kolmogorov Smirnov, the Anderson Darling and some graphical tests, are employed to test if the 3LL distribution is a good fit to the data. The maximum likelihood method is used to estimate the parameters. The distribution fit is important as it then becomes possible to quantify and manage the SO2 emissions effectively. The 3LL distribution, which is compared with three other distributions, gave the best overall fit to most of the power stations. Highlights • Quantification of SO2 emissions in terms of a statistical distribution • Calculating the probability of SO2 emissions exceeding certain specified limits • Ranking power stations in terms of SO2 emissions efficiency <![CDATA[<b>Optimal slope angle selection of an evacuated tube collector for domestic solar water heating</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1021-447X2017000100010&lng=pt&nrm=iso&tlng=pt A pressurised system utilising evacuated tube collectors with internal heat pipes was investigated for the production of hot service-water for domestic use during all seasons in Pretoria, South Africa. The investigation focused on the prediction of seasonal hourly performance trends and the maximum thermal performance at the optimal slope angle. This study was accomplished by developing the system's theoretical performance model which was solved numerically using Engineering Equation Solver. Results show the thermal performance of the system during the sequential seasons at different slope angles. Optimal performance parameters that influence the collector overall performance, depending on the water consumption of the occupants, were obtained and presented. In summer, a 25° slope angle produced the highest useful heat rate and in winter, a slope angle of 40 produced the highest. Lastly, a 20-tube collector system operated maximally in September, reaching an outlet temperature of 103.98 °C and yielding a useful heat rate of 1 919.85 W . <![CDATA[<b>The impact of petrol price movements on South African inflation</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1021-447X2017000100011&lng=pt&nrm=iso&tlng=pt This paper analyses the impact of petrol price movements on inflation outcomes in South Africa since the mid-1970s. The results show that, over time, the direct contribution of petrol inflation to headline inflation has not only increased, but has also exceeded its weight in the consumer price index. In addition, Granger causality tests and the autoregressive distributed lag approach to co-integration testing reveal that petrol prices have an important bearing on the prices of other (non-petrol) commodities in the economy. The results essentially show that petrol price increases had an important bearing on inflation outcomes in South Africa. This implies that petrol price movements warrant special attention in policy formulation and implementation in South Africa if inflation outcomes were to be kept in check.