Scielo RSS <![CDATA[Journal of Energy in Southern Africa]]> http://www.scielo.org.za/rss.php?pid=1021-447X20080001&lang=es vol. 19 num. 1 lang. es <![CDATA[SciELO Logo]]> http://www.scielo.org.za/img/en/fbpelogp.gif http://www.scielo.org.za <![CDATA[<b>The impact of electricity crises on the consumption behaviour of small and medium enterprises</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1021-447X2008000100001&lng=es&nrm=iso&tlng=es Small and medium enterprises (SMEs) will play a key role in future economic and social strategies in South Africa. However, we find that SMEs are particularly vulnerable to shocks in their external environment due to a general lack of skills and resources. This is critical as the future demand for electricity in South Africa is likely to outstrip supply and electricity will become increasingly unreliable and expensive. We surveyed 250 SMEs in Cape Town and found that the prevailing policy methods of changing electricity consumption behaviour: information campaigns, increasing prices, and providing rebates for energy savings, have had limited results and are unsustainable when applied to SMEs. <![CDATA[<b>A review of carbon dioxide capture and sequestration and the Kyoto Protocol's clean development mechanism and prospects for Southern Africa</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1021-447X2008000100002&lng=es&nrm=iso&tlng=es The clean development mechanism (CDM) of the Kyoto Protocol is a financial incentive intended to make economically marginal greenhouse gas (GHG) prevention projects more feasible. Carbon dioxide capture and sequestration (CCS) is a possible GHG mitigating strategy. The Intergovernmental Panel on Climate Change (IPCC) defines a CCS project as a process consisting of three phases: the separation of carbon dioxide from industrial and energy-related sources; transportation of the carbon dioxide to a storage location; and long-term isolation of the carbon dioxide from the atmosphere. This paper focuses on prospects of CCS as CDM projects in general and in the context of Southern Africa. Currently there is no evidence of a long term proven track record of integrated CCS systems; only three industrial scale CCS projects exist globally. Nevertheless, new concepts have been proposed for CCS CDM projects such as long-term liability and certified emission reduction (CER) cancellation. However, these concepts are not in the current CDM framework at present. It is thus difficult to prove CCS as an eligible CDM project without first addressing possible expansion and shortfalls of the current CDM structure. More research is also required to quantify the trade offs presented between mitigating carbon dioxide from the atmosphere at the possible detriment of the areas of storage in the Southern Africa context. Only then may CCS projects be deemed more viable in the CDM context. Finally, although the potential for CCS in South Africa has been noted due to major point sources, the cost of capture and storage is a major obstacle; matching point sources and geological storage options is problematic for South Africa and neighbouring countries due to large transport distances. The regulatory risks associated with CCS are further deterrents for the implementation of CCS CDM projects in Southern Africa in the near future. <![CDATA[<b>Life cycle energy analysis of environmental management reports in the Japanese automotive industry: Learning from the Japanese experience</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1021-447X2008000100003&lng=es&nrm=iso&tlng=es This paper discusses the assessment and comparison of the life cycle energy impacts of paper-based and electronic environmental reports in the Japanese automotive industry By January 2007, there were 129 031 ISO 14001 certified organisations and an additional 5389 certified to the European eco-management and audit scheme (EMAS). Energy use and the environmental burdens of environmental reporting by these companies, has grown and can no longer be ignored. Electronic systems are often portrayed as being more environmentally beneficial than traditional ones, for environmental reporting. However there are no known assessment methodologies that address this subject. This paper therefore creates a framework for analysing the two systems. Energy consumption models are developed within a life cycle assessment (LCA) framework and applied to the traditional and electronic systems respectively. A postal system model is developed for energy consumption in traditional mail distribution in Japan under six different scenarios. Data gaps in the Japanese automotive industry are compensated for by the use of justified assumption and sensitivity analysis of the variables concerned. Simulation results are analysed and some decision issues deciphered. A comparative analysis of electronic and traditional environmental reports identifies the necessary preconditions for reducing environmental burdens of the overall environmental management system (EMS). <![CDATA[<b>Developing ESCo procedures for large telecommunication facilities using novel simulation techniques</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1021-447X2008000100004&lng=es&nrm=iso&tlng=es Peak electricity demand in South Africa will exceed the available operational generation capacity in 2007. The state utility, Eskom, is addressing this challenge, inter alia, with the implementation of a national Demand-side Management (DSM) initiative. Studies in South Africa have shown that 20% of the total municipal energy is utilised in commercial buildings. Telecommunication companies own and operate a large portfolio of diverse buildings within the municipal boundaries. Energy Services Company (ESCO) analyses on these buildings showed huge savings as well as load reduction opportunities. ESCOs however face major problems in evaluating DSM projects on telecommunication facilities. To address these problems a new ESCO procedure for telecommunications facilities was developed and successfully implemented. It was proven that the new ESCO procedure is successful in solving the unique problems in performing ESCO analyses for telecommunications facilities. <![CDATA[<b>Contribution analysis of electrical energy management in the industrial and commercial sector: A challenge to the Tanzania utility industry</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1021-447X2008000100005&lng=es&nrm=iso&tlng=es The investigation of electrical energy management (EEM) in the industrial and commercial sector determines how energy management affects electricity consumption and what makes its potential for being used to reduce peak demand of utility industries. The aim of this paper is to analyze the contribution of electrical energy management in the industrial and commercial sector and highlight its challenges to the Tanzanian utility industry. Energy efficiency technology analyzed in this paper includes energy efficiency lighting and power factor improvement. The analysis found that, if EEM is properly implemented, a significant amount of energy could be saved and could be converted to monetary benefits which might facilitate the development of other activities. The utility industry can benefit from saving considerable amounts of energy as well as the reduction of peak demand which can minimize the race of stumbling on new energy sources and construction of new power plants. The saved energy can be distributed to other consumers so as to improve accessibility or reliability of the electrical system and consequently minimize the impact of environmental pollution. <![CDATA[<b>Electrical and thermal analysis of an asynchronous machine for application in wind energy generation</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1021-447X2008000100006&lng=es&nrm=iso&tlng=es The electromagnetic (electrical) and mechanical design of an Asynchronous machine for application in wind energy generation depends on the knowledge of heat transfer within the various parts of the machine. Unfortunately, the analysis of thermal effect in Asynchronous motors is usually more complex, more non-linear and more difficult than the electromagnetic behaviour. This paper therefore, sets out to investigate the effect of coupling the electrical model with the thermal model of the machine. The results of the analysis show that the proposed coupled model is capable of predicting the stator phase currents, rotor bar temperature, stator windings temperature, heat losses, rotor speed and electromagnetic torque of the test machine under dynamic conditions and at rated load operation. The analysis finds application in wind energy generation especially when modified and applied to synchronous generators. By so doing, the prediction of critical temperatures of machine parts can be achieved prior to machine operation. <![CDATA[<b>Experimental results of using a parabolic trough solar collector for thermal treatment of crude oil</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1021-447X2008000100007&lng=es&nrm=iso&tlng=es At present, there are economic, ecological and energy efficiency problems in dealing with the oil industry. We have tried to solve this problem through a solar thermal application. Thus, parabolic-trough solar plant utilization in the oil industry is a relatively new application in the area of solar energy usage. In Azerbaijan (Baki), such an application has firstly been realized in the crude oil treatment process by us. We must mention that a solar energy application has a great advantage for the oil industry to be economical with fossil fuels partly, to improve safety measures and ecology, and to also reduce additional financial expenses. Besides the ecological and economical facets, the obtained results from the experiments, which have been carried out in the Absheron Peninsula (Baki), are useful from an energy efficiency point of view in the field of solar thermal applications by using parabolic troughs. These experimental results are significant on account of economic, energy efficient and ecological advantages. <![CDATA[<b>An analysis of a thermal power plant working on a Rankine cycle: A theoretical investigation</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1021-447X2008000100008&lng=es&nrm=iso&tlng=es Today, most of the electricity produced throughout the world is from steam power plants. However, electricity is being produced by some other power generation sources such as hydropower, gas power, bio-gas power, solar cells, etc. One newly developed method of electricity generation is the Magneto hydro dynamic power plant. This paper deals with steam cycles used in power plants. Thermodynamic analysis of the Rankine cycle has been undertaken to enhance the efficiency and reliability of steam power plants. The thermodynamic deviations resulting in non-ideal or irreversible functioning of various steam power plant components have been identified. A comparative study between the Carnot cycle and Rankine cycle efficiency has been analyzed resulting in the introduction of regeneration in the Rankine cycle. Factors affecting efficiency of the Rankine cycle have been identified and analyzed for improved working of thermal power plants.