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1
Baker, Lucy, and Jon Phillips. "Tensions in the transition: The politics of electricity distribution in South Africa." Environment and Planning C: Politics and Space 37, no. 1 (June 11, 2018): 177–96. http://dx.doi.org/10.1177/2399654418778590.
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This paper argues that the distribution of electricity represents an important yet neglected aspect of the politics of energy transitions. In recent years, South Africa’s electricity sector has seen the introduction of new actors and technologies, including the ‘prosumer’ (producer–consumer) of electricity and small-scale embedded generation from roof-top solar photovoltaics. We analyse these recent developments in historical context and consider implications for contemporary planning, regulation and ownership of electricity. We find that the reconfiguration of electricity distribution faces significant political and economic challenges that are rooted in the country’s socio-economic and racial inequalities and its heavy dependence on coal-fired power. First small-scale embedded generation offers potential opportunities for affordable, decentralised, low-carbon energy, yet disruption to the coal-powered electric grid and the monopoly of South Africa’s electricity utility has been minimal to date. Second, small-scale embedded generation creates tensions between equitable and low-carbon energy transitions and threatens critical revenue from the country’s wealthy consumers that cross-subsidises electricity services for the poor and other municipal public services. Third, the South African experience queries common assumptions about the democratic potential of decentralised governance. Fourth, South Africa provides insights of global significance into how political institutions have responded to social and technological drivers of change, in a context where planning and regulation have followed rather than led infrastructural developments. While energy policy remains unresponsive or resistant to social and technological change, there remain significant political, economic, technical and regulatory challenges to a just and inclusive energy transition.
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Masembe, Angela. "Reliability benefit of smart grid technologies: A case for South Africa." Journal of Energy in Southern Africa 26, no. 3 (September 23, 2015): 2–9. http://dx.doi.org/10.17159/2413-3051/2015/v26i3a2124.
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The South African power industry faces many challenges, from poor performing networks, a shortage of generation capacity to significant infrastructure backlog and an ageing work force. According to the Development Bank of South Africa (DBSA), the key challenge facing the industry is ageing infrastructure. Smart grid technologies are a class of technologies that are being developed and used by utilities to deliver electrical systems into the 21st century using computer-based remote control and automation. The main motive towards smart grid technologies is to improve reliability, flexibility, accessibility and profitability; as well as to support trends towards a more sustainable energy supply. This study identifies a number of smart grid technologies and examines the impact they may have on the distribution reliability of a test system. The components on the selected test system are the same as those found on a South African feeder. The bulk of the load in test system was modelled using load data collected in South Africa. This study will consider a number of different cases, with the base case incorporating the impact of aged infrastructure on the reliability of the system. The smart grid technologies were then introduced into the system and their impact on distribution reliability was determined. These different cases were also compared to the alternative of replacing the aged and worn out infrastructure with new infrastructure. The findings of this study indicate that the identified smart grid technologies improve the reliability of the system, mainly by decreasing the outage duration experienced by customers on the network. An even better performance was achieved when the ageing infrastructure was replaced with new infrastructure.
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G. A, Adepoju, Oshin Ola Austin, Kabir A. Lasisi, Ajayi Joseph Adeniyi, and Oluwasanmi Alonge. "Development of a Model for the Establishment of a Hydro Electric Power Generating Plant." Journal La Multiapp 1, no. 3 (December 2, 2020): 27–42. http://dx.doi.org/10.37899/journallamultiapp.v1i3.207.
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Nigeria as a nation has suffered a lot when it comes to the availability of electricity. A clear comparison between this nation’s electric power supply and other countries revealed the present incessant electric power supply in the country. The average power per capital (watts per person) in the United States is 1,377 Watts. In Canada, it is as high as 1,704 Watts per person and in South Africa; it is 445 Watts per person. The average power per capital in Australia is 1,112 Watts and in New Zealand it is 1,020 W per person. Whereas, the average power per capital (watts per person) in Nigeria is 14 W person. The power system structure is characterized with a lot of faults and outages. These electric power problem has destroyed the industrial processes in the country. As a result, unemployment has increased in the country. As at February, 2020, according to the Federal Government of Nigeria, the number of unemployed youths in the country is 23 million. Data from the International Transparency in the United State stated that there are 40 million unemployed youths in the country. This has increased crime rates among the youths. The country experience a high level of hardship, insecurity and socio-economic disorder as results. Therefore, there is an urgent need to solve this incessant supply of electric power in the country. Hence, a detail study of Akure132/33kV substation Network of the Benin Electricity Distribution Company under which there are 84,264 customers was carried out.
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Gutschow, D., and M. O. Kachieng'a. "Making Business Sense of Distribution Automation Systems: The Case of Eskom, South Africa." IEEE Transactions on Power Systems 20, no. 1 (February 2005): 272–78. http://dx.doi.org/10.1109/tpwrs.2004.841215.
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Mzini, Loraine, and Tshombe Lukamba-Muhiya. "An assessment of electricity supply and demand at Emfuleni Local Municipality." Journal of Energy in Southern Africa 25, no. 3 (September 23, 2014): 20–26. http://dx.doi.org/10.17159/2413-3051/2014/v25i3a2654.
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Globally, electricity has become a modern tool to supply energy to households. This study investigates the supply and demand of household electricity and sustainability of distribution centres at Emfuleni Local Municipality (ELM). South Africa follows a vigorous programme of electrification, spearheaded by Eskom. Eskom is a South African state-owned power company which strives to meet the country’s increasing demand for energy. Resi-dential energy demand is growing as population levels rise and the number of households in ELM increases. Recently (2008–2010) in South Africa there have been unprecedented levels of load shedding nationally and there is a shortage of centres to purchase electricity. Furthermore, households do not receive uninterrupted electricity on a daily basis, largely because of stolen electrical cables and illegal connections. Low-income residents of Evaton, ELM, were interviewed. Empirical surveys were conducted and a theoretical exposition drawn up to meet the objectives of the study. It was found that electricity supply and demand in ELM is adequate but there is a shortage of selling points in Evaton and there are barriers towards the effectiveness of electricity consumption. In addition, public awareness programmes must continue to educate the communities to avoid stealing the electrical cables. Illegal connection must be reported to the local councillors for them to make sure that this activity is stopped in Evaton.
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Raji, Atanda, and Mohamed Tariq Kahn. "Analysis of distributed energy resources for domestic electricity users." Journal of Energy in Southern Africa 23, no. 2 (May 1, 2012): 50–55. http://dx.doi.org/10.17159/2413-3051/2012/v23i2a3163.
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After over a century with utilization of the benefits of economics of scale, power systems planning and development gets bigger and transmission grids have needed to transmit wide bringing the concept of onsite or close-to-load generation back. The turnaround strategy is prompted by market liberalization, transmission expansion constraints, related technology advancements, environmental pollution, health hazards, fossil fuel depletion, and climate change concerns. In the last decade, many countries have started the process of liberalisation of the electric systems, opening access to transmission and distribution grids.Technical feasibility analysis of a hybrid energy system for two types of geographical regions in South Africa using Homer is performed in this paper. Wind-PV hybrid systems are modelled as a micro-power system using Homer. The simulation results analyses conducted for a typical middle income earner electricity load profile for both a coaster and inlander domestic users of electricity showed that Wind-PV hybrid system is technically feasible and economical.
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Ockwell, David, Robert Byrne, Joanes Atela, Victoria Chengo, Elsie Onsongo, Jacob Fodio Todd, Victoria Kasprowicz, and Adrian Ely. "Transforming Access to Clean Energy Technologies in the Global South: Learning from Lighting Africa in Kenya." Energies 14, no. 14 (July 20, 2021): 4362. http://dx.doi.org/10.3390/en14144362.
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As SDG7-related interventions seek to transform access to clean energy, this paper presents an analysis of both a previous transformative intervention (Lighting Africa) and a theoretical approach to understanding how such transformations can be achieved in the Global South (socio-technical innovation system, STIS, building). The paper makes four contributions. First, it tests the extent to which the STIS-building concept is useful in understanding and conceptualising how Lighting Africa transformed the market for solar lanterns in Kenya from an estimated market size of 29,000 lamps in 2009 to one where 680,000 Lighting Africa certified lamps were sold in Kenya by the end of the Programme in 2013. Second, it presents the most in-depth analysis of Lighting Africa that we are aware of to date. Third, it presents a conceptual framework that illustrates the Lighting Africa approach, providing a framework for future policy interventions aiming to transform access to clean energy technologies in the Global South. Fourth, it reflects on weaknesses in the STIS approach. In particular, these include a need to better attend to: the gendered implications of interventions (and social justice more broadly); implications of different scales of technologies; value accumulation and the extent to which interventions benefit indigenous actors and local economies; and the political and economic implications of any intervention and its distribution of benefits.
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Dijk, Marco van, Giovanna Cavazzini, Gideon Bonthuys, Alberto Santolin, and Jacques van Delft. "Integration of Water Supply, Conduit Hydropower Generation and Electricity Demand." Proceedings 2, no. 11 (August 1, 2018): 689. http://dx.doi.org/10.3390/proceedings2110689.
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South Africa is acknowledged to be not particularly endowed with the best hydropower conditions as it might be elsewhere in Africa and the rest of the world, however, large quantities of raw and potable water are conveyed daily under either pressurized or gravity conditions over large distances and elevations. There exists conduit hydropower generation potential in the water supply and distribution systems belonging to municipalities, water supply utilities and mines. Bloemwater, a water utility, constructed a stand-alone turbine, based on the available pressure and flow which generates a constant output ranging between 55 and 96 kW and when sufficient, supplies the head-office. Initially a manual changeover was utilized to switch between the hydropower and the local electricity supplier when the hydropower was insufficient to meet the demand i.e. switching of the full load from the one source to the other. To maximize the utilization of the hydropower, an automatic change over panel was developed to deal with the variable electricity demand from the office. The office building’s electrical distribution was divided into different distribution boards to allow each sector to be supplied and switched individually with 6, PLC controlled, motorized change-over switches. The PLC constantly evaluates and subsequently executes switching actions so that Bloemwater can utilize the maximum renewable hydropower, but also limits power interruptions to a minimum because of these switching actions. This technical paper describes the development of this conduit hydropower plant by evaluating the interrelationship of water supply, electricity demand and operating cycles, providing Bloemwater with the optimum solution with increased resiliency and sustainability.
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Nasir, Mashood, Hassan Abbas Khan, Irfan Khan, Naveed ul Hassan, Nauman Ahmad Zaffar, Aneeq Mehmood, Thilo Sauter, and S. M. Muyeen. "Grid Load Reduction through Optimized PV Power Utilization in Intermittent Grids Using a Low-Cost Hardware Platform." Energies 12, no. 9 (May 9, 2019): 1764. http://dx.doi.org/10.3390/en12091764.
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Renewable energy incorporation in many countries takes different forms. In many developed countries, grid-tied solar photovoltaic (PV) installations are widely coupled with lucrative Feed-in-Tariffs (FiT). However, conventional grid-tied solutions are not readily viable in many developing countries mainly due to intermittent grids with load shedding and, in some cases, lack of net-metering or FiT. Load shedding refers to an intentional electrical power shutdown by the utility company where electricity delivery is stopped for non-overlapping periods of time over different parts of the distribution region. This results in a non-continuous availability of the utility grid for many consumers over the course of a day. In this work, the key challenges in the integration of solar energy explicitly in residential power back-up units are reviewed and system hardware level requirements to allow optimized solar PV utilization in such intermittent grid environments are analyzed. Further, based upon the low-cost sensing and real-time monitoring scheme, an online optimization framework enabling efficient solar incorporation in existing systems to achieve minimum grid dependence in intermittent grid environments is also provided. This work is particularly targeted for over 1.5 billion residents of semi-electrified regions in South Asia and Africa with the weak and intermittent grid.
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Mosetlhe, Thapelo Cornelius, Adedayo Ademola Yusuff, and Yskandar Hamam. "Investigating seasonal wind energy potential in Vredendal, South Africa." Journal of Energy in Southern Africa 29, no. 2 (June 22, 2018): 77–83. http://dx.doi.org/10.17159/2413-3051/2018/v29i2a2746.
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Global warming and the energy crisis have necessitated an urgent exploitation and utilisation of renewable energy. Wind energy has gained popularity over the years because of vast availability of its resource. A study was carried out to investigate the stochastic characteristics of the available wind energy at installation sites. Data for a ten-minute interval wind speed collected over a period of five years and measured at a height of 10, 40 and 62 m in Vredendal was considered. Wind speed data was arranged in seasonal format and its statistical distribution investigated based on Weibull, lognormal and gamma distributions. The Anderson-Darling test and Akaike information criterion were used to evaluate the goodness of fit. The results showed that wind power at different heights and time stamps exhibited different statistical distribution. It was found that wind turbines in Vredendal must be installed as high as possible to harness wind power effectively. During summer and spring, there was a high potential for wind power availability compared with that of winter.
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Schenoni, Luis Leandro. "Subsystemic Unipolarities? Power Distribution and State Behaviour in South America and Southern Africa." Strategic Analysis 41, no. 1 (December 5, 2016): 74–86. http://dx.doi.org/10.1080/09700161.2016.1249179.
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Jay, Mary. "Co-publishing with Africa North–South–North." Logos 31, no. 2 (September 4, 2020): 19–27. http://dx.doi.org/10.1163/18784712-03102003.
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The decolonization of African studies extends beyond content to ethical partnerships between the North and the African continent. One key component of realizing partnership is through publishing. African studies research published by Northern publishers is not often even minimally available in Africa; and this is despite scholars on the continent often being partners or facilitators in research undertaken by Northern scholars. Northern publishers have perceived no commercial gain, given small African markets, lack of purchasing power, and lack of distribution systems. Conversely, African publishers have efficient distribution into the North through African Books Collective, owned and governed by them. But in suitable rare cases the African publisher can broker co-publications with Northern publishers who want the originating rights. In the light of these issues, African Books Collective launched an initiative to seek to break the deadlock. In partnership with the International African Institute, and with the active support of the African Studies Associations of the UK and the US, work is proceeding with publishers in the North and the South to broker co-publishing or co-editions to address this historic marginalization of Africa.
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Ballance, A., D. Stephenson, R. A. Chapman, and J. Muller. "A geographic information systems analysis of hydro power potential in South Africa." Journal of Hydroinformatics 2, no. 4 (October 1, 2000): 247–54. http://dx.doi.org/10.2166/hydro.2000.0022.
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Electrification can reduce the dependence on combustible fuels and therefore also reduce the concomitant health risks. Hydro power is one possible method of generating electric power close to the potential consumers, thereby cutting out expensive reticulation costs in widely spread rural areas. For sustainable electricity generation there must be stream flows of sufficient flow rates down significant slopes. A preliminary assessment of hydro power potential in South Africa was undertaken by estimating actual energy potential calculated from digital maps of slope and runoff. Coefficients of variation and low flow indices proved good potential measures of flow variability and risk. The methodology allowed rapid identification of micro- and macro-hydro power potential. Micro-hydro power potential identification was calculated from run of river and local flow, while macro-hydro power generation needs storage and thus cumulative river flows were used. The steeper and more humid slopes of the eastern escarpment, and parts of the southern escarpment near Cape Town, showed the best potential for both micro- and macro-hydro power (with annual energy potential values in excess of 107 kWh yr−1 and 109 kWh yr−1, respectively). This preliminary assessment was intended to lead to further more detailed and in-field assessments of hydro power generating capacity.
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Singh, A., and A. G. Swanson. "Development of a Plant Health and Risk Index for Distribution Power Transformers in South Africa." SAIEE Africa Research Journal 109, no. 3 (September 2018): 159–70. http://dx.doi.org/10.23919/saiee.2018.8532192.
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Agyei-Sakyi, Mark, Yunfei Shao, Oppong Amos, and Armah Marymargaret. "Determinants of Electricity Consumption and Volatility-Driven Innovative Roadmaps to One Hundred Percent Renewables for Top Consuming Nations in Africa." Sustainability 13, no. 11 (June 1, 2021): 6239. http://dx.doi.org/10.3390/su13116239.
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The determinants of providing affordable electricity for all in top energy-consuming African countries vary and are in line with the percentage of the current population with access to electricity and volatility in a country’s electric power system, but there is rare evidence of such research. This study categorizes Egypt–Algeria as a panel of countries with 100% access to electricity, and Nigeria–South Africa as otherwise, to investigate the causal relationship between domestic electricity demand, renewable electricity generation, population, and GDP. The study proposed and implemented a novel machine learning model for viable and volatility-driven pathways for renewable electric power transition up to 2030. Results from Pedroni cointegration analysis suggest no evidence of long-run relationships among the variables. Nonetheless, there exists a short-run unidirectional causal relationship from GDP to electricity consumption for Nigeria–South Africa; all except Egypt can achieve 100% access to green electricity. The implication is that, through radical renewable electricity generation innovations, countries can achieve renewable-dominated electric power systems despite expected disruptions from the coronavirus pandemic. For sustainable energy planning, countries aiming to achieve 100% renewables is possible due to the radical transition pathways since it takes into account the volatility.
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Bokanga, Gilbert M., Atanda Raji, and Mohammed T. E. Kahn. "Design of a low voltage DC microgrid system for rural electrification in South Africa." Journal of Energy in Southern Africa 25, no. 2 (June 23, 2014): 9–14. http://dx.doi.org/10.17159/2413-3051/2014/v25i2a2664.
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This project entails the design of a low voltage DC microgrid system for rural electrification in South Africa. Solar energy is freely available, environmental friendly and it is considered as a promising power generating source due to its availability and topological advantages for local power generation. Off-grid solar systems are perceived to be a viable means of power delivery to households in rural outlying areas in South Africa as solar panels can be used almost anywhere in the country. The design presented in this paper is based on the power demand estimation, photovoltaic panel selection, battery sizing and wire selection for the distribution system.
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Vladisavljevic, Nebojsa, and Katrin Voltmer. "Media framing of democratisation conflicts in Egypt, Kenya, Serbia and South Africa." Sociologija 59, no. 4 (2017): 518–37. http://dx.doi.org/10.2298/soc1704518v.
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This paper presents an overview of the main findings from a quantitative content analysis covering different types of democratisation conflicts (i.e., conflicts over citizenship, elections, transitional justice and distribution of power) in Egypt, Kenya, Serbia and South Africa. The key findings from the content analysis are organised around several themes: causes of democratisation conflicts, portrayal of conflict parties, preferred solutions to conflicts, perceptions of democracy, role of the media, authoritarian past, and tone of reporting and polarisation. The main finding is that cross-national variations depend on several factors: specific country contexts (and contexts of broader regions from which they come from, including the Arab Middle East, sub-Saharan Africa and post-communist Europe); regime type and the stage of democratisation; and type of democratisation conflict (which reflects the main arenas of political contestation). Across all countries, the quality of media coverage is limited by bias, emotionalisation and - most importantly - polarisation. In particular, conflicts over the distribution of power trigger sharp polarisation, whereas elections - contrary to existing literature - seem to force media towards a more restrained style of reporting. The sample involves 5162 newspaper articles and news stories from the four countries.
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Olosunde, Akinlolu, and Rowland Benjamin Ekpo. "HALF EXPONENTIAL POWER MODEL FOR THE FIRST TIME FAILURE OF POWER DISTRIBUTION TRANSFORMERS IN NIGERIA." Indonesian Journal of Statistics and Its Applications 4, no. 2 (July 31, 2020): 321–26. http://dx.doi.org/10.29244/ijsa.v4i2.640.
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Transformer failure is a major problem confronting the Nigerian power sector, hindering the transmission and distribution of electric power to various households, institutions, and industries. Many of these transformer developed problem due to the old age of the transformers, overloading, in-availability of technical expertise, poor maintenance culture, manufacturer's faults, just to mention few. The present research focuses on providing half exponential power model for the failure of already installed transformers, with respect to years of installation up to the time of the first failure, using secondary data from the south western part of Nigeria as a case study. The results obtained showed that half exponential power performed better in modeling the first time failure of power transformers. This was possible because of the present of shape parameter which gives flexibility to half exponential power when compared with a half normal distribution.
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Adefarati, Temitope, and G. D. Obikoya. "Evaluation of Wind Resources Potential and Economic Analysis of Wind Power Generation in South Africa." International Journal of Engineering Research in Africa 44 (August 2019): 150–81. http://dx.doi.org/10.4028/www.scientific.net/jera.44.150.
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The presence of adequate renewable energy resources and the rapid development of wind projects in South Africa have led to mapping out of the country’s wind capability. In view of this, the economic prospects of utilizing wind energy as a potential energy alternative in South Africa are examined and discussed from the perspectives of green energy strategies for sustainable energy development. This research work is designed to investigate the economic effects of using the wind turbine (WT) in ten locations in South Africa based on the grid planning and power sector reform. The HOMER application software is utilized in this study to assess the wind resources on provincial and national scales, along with estimating the annual energy generation of the selected locations. The wind energy potential of South Africa is analysed by utilizing the capacity factor (CF), wind penetration and mean output of the WT for various locations in South Africa. The results obtained from the study indicate that the selected sites fall within the range of Class 1V of IEC wind classifications with the annual average wind speed of 4.04 m/s for Pretoria and 6.39 m/s for Cape Town at 50m hub heights. The economic assessment of the WT for electric power generation is carried out by using some key performance indicators (KPIs) such as net energy purchased, energy sold, revenue, grid energy purchased, annual utility bill savings, net present cost (NPC) and cost of energy (COE). It is established from the study that Cape Town is the most suitable location for installation of the WT by utilizing the same load profile and system configuration. The output of this research work can be used by the renewable energy development agencies as inputs to harness the potential of wind resources for strategic planning of the power sector reform and industrial development.
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Ayodele, T. R., A. A. Jimoh, J. L. Munda, and J. T. Agee. "A Statistical Analysis of Wind Distribution and Wind Power Potential in the Coastal Region of South Africa." International Journal of Green Energy 10, no. 8 (September 14, 2013): 814–34. http://dx.doi.org/10.1080/15435075.2012.727112.
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Saponara, Sergio, and Lucian Mihet-Popa. "Energy Storage Systems and Power Conversion Electronics for E-Transportation and Smart Grid." Energies 12, no. 4 (February 19, 2019): 663. http://dx.doi.org/10.3390/en12040663.
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The special issue “Energy Storage Systems and Power Conversion Electronics for E-Transportation and Smart Grid” on MDPI Energies presents 20 accepted papers, with authors from North and South America, Asia, Europe and Africa, related to the emerging trends in energy storage and power conversion electronic circuits and systems, with a specific focus on transportation electrification and on the evolution of the electric grid to a smart grid. An extensive exploitation of renewable energy sources is foreseen for smart grid as well as a close integration with the energy storage and recharging systems of the electrified transportation era. Innovations at both algorithmic and hardware (i.e., power converters, electric drives, electronic control units (ECU), energy storage modules and charging stations) levels are proposed.
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Essiet, Ima O., and Yanxia Sun. "Maximizing Demand Response Aggregator Compensation through Optimal RES Utilization: Aggregation in Johannesburg, South Africa." Applied Sciences 10, no. 2 (January 14, 2020): 594. http://dx.doi.org/10.3390/app10020594.
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This paper examines the role of demand response aggregators in minimizing the cost of electricity generation by distribution utilities in a day-ahead electricity market. In this paper, 2500 standard South African homes are considered as end users. Five clusters (and aggregators) are considered with 500 homes in each cluster. Two cases are analysed: (1) Utilization of renewable energy sources (RES) is implemented by the distribution supply operator (DSO), where it meets excess demand for end users during peak hours by purchasing electricity from the renewable sources of the energy market, and (2) Utilization of RES is implemented by end users alone, and it is assumed that every household has one plug-in electric vehicle (PEV). The aggregators then compete with each other for the most cost-effective energy usage profile; the aggregator with the least energy demand wins the bid. In both cases, energy pricing is estimated according to the day-ahead energy market. A typical day during winter in Johannesburg is considered for the simulation using a genetic algorithm (GA). Results obtained demonstrate the effectiveness of demand response aggregators in maximizing the benefits on both sides of the electricity supply chain.
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Okedeyi, Olumuyiwa O., Mathew M. Nindi, Simiso Dube, and O. R. Awofolu. "Distribution and potential sources of polycyclic aromatic hydrocarbons in soils around coal-fired power plants in South Africa." Environmental Monitoring and Assessment 185, no. 3 (June 4, 2012): 2073–82. http://dx.doi.org/10.1007/s10661-012-2689-7.
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Abdallah, Lamiaa, and Tarek El-Shennawy. "Reducing Carbon Dioxide Emissions from Electricity Sector Using Smart Electric Grid Applications." Journal of Engineering 2013 (2013): 1–8. http://dx.doi.org/10.1155/2013/845051.
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Approximately 40% of global CO2emissions are emitted from electricity generation through the combustion of fossil fuels to generate heat needed to power steam turbines. Burning these fuels results in the production of carbon dioxide (CO2)—the primary heat-trapping, “greenhouse gas” responsible for global warming. Applying smart electric grid technologies can potentially reduce CO2emissions. Electric grid comprises three major sectors: generation, transmission and distribution grid, and consumption. Smart generation includes the use of renewable energy sources (wind, solar, or hydropower). Smart transmission and distribution relies on optimizing the existing assets of overhead transmission lines, underground cables, transformers, and substations such that minimum generating capacities are required in the future. Smart consumption will depend on the use of more efficient equipment like energy-saving lighting lamps, enabling smart homes and hybrid plug-in electric vehicles technologies. A special interest is given to the Egyptian case study. Main opportunities for Egypt include generating electricity from wind and solar energy sources and its geographical location that makes it a perfect center for interconnecting electrical systems from the Nile basin, North Africa, Gulf, and Europe. Challenges include shortage of investments, absence of political will, aging of transmission and distribution infrastructure, and lack of consumer awareness for power utilization.
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Ayeleso, Ayokunle Oluwaseun. "EXPERIMENTAL CHARACTERIZATION OF A MAGNETOHYDRODYNAMIC POWER GENERATOR UNDER DC ARC PLASMA." Acta Polytechnica 58, no. 1 (February 28, 2018): 1. http://dx.doi.org/10.14311/ap.2018.58.0001.
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The generation of electric power through the conventional systems (thermal and hydroelectric) is no longer sufficient to meet the increasing industrial and commercial usage. Therefore, an alternative energy conversion system is currently being sought. The aim of the presented study is to develop a direct energy conversion system (Magnetohydrodynamics, MHD generator) to generate electric power using plasma. Additionally, the generator electric response is investigated based on the Faraday’s principle of electromagnetism and fluid dynamics. For this purpose, a rectangular MHD generator prototype with segmented electrodes was constructed and subjected to continuous plasma from a DC arc source at test facilities available in the Western Cape region (South Africa). Subsequently, the terminal voltages at the middle-electrodes were measured one after another across 1, 100 and 470 Ω load resistors. In all experiments, the absolute time-averages of the measured terminal voltage across each load resistor were similar, which indicates a generation of power. The maximum power of the order 0.203mW was obtained when 1 Ω resistor was connected to the middle-electrodes. Conclusively, these results validate the measurement approach of the MHD generator with segmented electrodes and could be used to design a large MHD unit that can be incorporated to the existing conventional thermal plant to improve their cyclic thermal efficiency.
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Ijumba, Pamela, and Adoniya Ben Sebitosi. "Evaluating the impact of consumer behaviour on the performance of domestic solar water heating systems in South Africa." Journal of Energy in Southern Africa 21, no. 1 (February 1, 2010): 25–34. http://dx.doi.org/10.17159/2413-3051/2010/v21i1a3247.
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South Africa experienced a rapid expansion in the electric power consumer base after 1994 that was not matched by corresponding investment in the country’s generation capacity. By the dawn of 2008, the situation had reached a critical point, with regular countrywide blackouts and load shedding and is expected to persist for several years, before the proposed new base stations can come online. Currently, 92% of the country’s electricity is generated in coal-based power stations and are responsible for the country’s heavy carbon footprint. Additionally this power must crisscross the country to distant load centres via an aging transmission infrastructure and in the process massive amounts of energy are lost particularly during peak power demand. Electricity consumption in South African households accounts for approximately 35% of peak demand, with water heating constituting 40% of that. The country has abundant sunshine and solar water heating technology and offers one of the most viable compiementary solutions to the country’s energy and environmental crises. Moreover the location of the systems at the consumer end means that the need to upgrade the transmission infrastructure can also be differed.Application of technology alone however, may not necessarily result in the required energy savings particularly in cases of uninformed consumer usage. In this paper the authors evaluate the impact of consumer behaviour on the performance of domestic solar water heaters in South Africa and suggest measures that could be taken to optimize this performance.
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Legesse, Ayele Nigussie, Akshay Kumar Saha, and Ridiren Pillay Carpanen. "Characterisation of wind speed series and power in Durban." Journal of Energy in Southern Africa 28, no. 3 (September 22, 2017): 66. http://dx.doi.org/10.17159/2413-3051/2017/v28i3a1683.
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Both the planning and operating of a wind farm demand an appropriate wind speed model of its location. The model also helps predict the dynamic behaviour of wind turbines and wind power potential in the location. This study characterises the wind speed series and power in Durban (29.9560°S, 30.9730°E), South Africa, using Markov chain and Weibull distribution. Comparison of statistical quantities of measured and Markov model-generated wind speed series revealed that the model accurately represented the measured wind speed series. The Markov model and Weibull distribution were also compared through their corresponding probability density functions. The root mean square error of the Markov model against the measured wind speed series was nearly one-tenth that of the Weibull distribution, indicating the effectiveness of the former. Finally, the analysis of wind power density showed that Durban and its environs need large wind turbines with hub heights greater than 85 m for efficient utilisation of the available wind energy.
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Gudo, Adam Juma Abdallah, Jinsong Deng, Marye Belete, and Ghali Abdullahi Abubakar. "Estimation of Small Onshore Wind Power Development for Poverty Reduction in Jubek State, South Sudan, Africa." Sustainability 12, no. 4 (February 17, 2020): 1483. http://dx.doi.org/10.3390/su12041483.
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Energy security is one of the challenging issues hindering developmental progress in developing countries. Wind power as a renewable energy source can play a significant role in poverty reduction if adequate information is provided. In this study, multi-approach technics were applied for a better understanding of the wind energy potential in Jubek State, South Sudan. Geographic Information System (GIS), remote sensing, and mathematical equations were applied in identifying suitable locations, potential power per unit area, wind farm layout, design of appropriate turbine size, and utilization of wind energy in both agricultural and domestic sectors. Wind speed, land use land cover, and digital elevation maps of the study area were processed in ArcGIS, MATLAB (Weibull distribution), and Minitab software. The results show that 17,331.4 km2 (94.64%) of the study area is appropriate for wind power generation, with wind density of about 3.65 W/m2 and installation capacity about 19,757.79 MW, resulting in an annual energy production of about 7269.29 GWh. With the proposed wind turbine, one ton of various crops and animal products require 1–4 and 2–20 turbines, respectively. Therefore, the step-by-step procedures followed in this study will contribute to poverty reduction through improving agricultural productivity and food quality.
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Girmay, Maseapei Elizabeth, and Delson Chikobvu. "Quantifying South Africa’s sulphur dioxide emission efficiency in coal-powered electricity generation by fitting the three-parameter log-logistic distribution." Journal of Energy in Southern Africa 28, no. 1 (March 23, 2017): 91. http://dx.doi.org/10.17159/2413-3051/2017/v28i1a1530.
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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. Keywords: emission, Eskom, log logistic distribution, goodness of fit, sulphur dioxide, Burr-type distributionHighlightsQuantification of SO2 emissions in terms of a statistical distributionCalculating the probability of SO2 emissions exceeding certain specified limitsRanking power stations in terms of SO2 emissions efficiency
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Inglesi-Lotz, Roula, and James Blignaut. "Estimating the opportunity cost of water for the Kusile and Medupi coal-fired electricity power plants in South Africa." Journal of Energy in Southern Africa 23, no. 4 (November 1, 2012): 76–84. http://dx.doi.org/10.17159/2413-3051/2012/v23i4a3180.
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In South Africa, water is considered a limited source, not only because of the country’s arid nature, but also because of the relatively skew distribution of the resource and the fact that 98% of the resource is already allocated. Eskom, the South African electricity supplier, commenced with the construction of two new coal-fired power stations namely Kusile and Medupi. The question is: what is the opportunity cost of investing in these power stations from a water perspective? We do not argue here against the need for power plants and additional electricity generation capacity per se, but consider the opportunity cost of using this specific technology. We estimate the shadow price of water for different power generation technologies as an indicator of the opportunity cost of water. We apply a production function approach for a baseline case (coal-fired power generation using the Medupi and Kusile parameters), and four alternative technologies. The only alternative that performs worse than the baseline case is the traditional wet-cooling coal-fired power process. The baseline case, however, does show a high opportunity cost when compared to renewable alternatives (solar, wind and biomass) ranging from R0.66/kWh (biomass) to R0.83/kWh (solar) to R1.31/kWh (wind).
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Pitcher, M. Anne. "What Has Happened to Organized Labor in Southern Africa?" International Labor and Working-Class History 72, no. 1 (2007): 134–60. http://dx.doi.org/10.1017/s0147547907000579.
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AbstractWhy have labor movements in Mozambique, Zambia, and South Africa increasingly been marginalized from the economic debates that are taking place in their countries, even though they have supported ruling parties? Policy reforms such as trade liberalization, privatization, and revisions to labor legislation in all three countries partially account for the loss of power by organized labor as many scholars have claimed. Yet, these policy “adjustments” have also interacted with long-run, structural changes in production, distribution, and trade of goods as well as with processes of democratization to undermine the position of trade unions across much of southern Africa. The article explores this puzzle by first examining the different historical trajectories of organized labor in Mozambique, Zambia, and South Africa. It then analyzes how policy reforms, global restructuring, and democracy had similar consequences across all three cases; collectively, they produced declines in trade-union membership and weakened the influence of organized labor. Although trade unions face a number of daunting challenges, the conclusion traces emerging opportunities for labor to recover from its current malaise.
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Luiz, John M., and Grant Visser. "Strategic and architectural dimensions of the decision-making processes in South African multinational corporations." Journal of Management & Organization 20, no. 6 (November 2014): 832–50. http://dx.doi.org/10.1017/jmo.2014.56.
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AbstractWe examine the manner in which South African-owned multinationals devolve power to their international subsidiaries in Africa, and the resulting effects of the interaction between strategy and structure. The research suggests that a dynamic process of power distribution may develop, in terms of the following: (1) the performance of the subsidiary, its expertise and experience to adapt to local market demands; and (2) the multinational’s need to manage the risks propagated by the African operating environment in which it operates. There is a dual facet to power devolvement, one in which South African multinationals opt for risk mitigation through long-standing control, often at the expense of operational adaptation. In contrast with the literature, which sees multinational corporations as differentiated networks, in the South African case we find a more traditional approach with clear headquarters and ‘miniature replica’ subsidiaries. This suggests that South African multinational corporations are still emerging and that it will take time to develop differentiated networks.
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Saini, Makmur, A. M. Shiddiq Yunus, and Firdaus Firdaus. "Studi Estimasi Beban Puncak Hari Libur Nasional Sistem Interkoneksi Sulselbar Menggunakan Jaringan Syaraf Tiruan Propagasi Balik." Jurnal Teknik Mesin Sinergi 18, no. 2 (December 9, 2020): 170. http://dx.doi.org/10.31963/sinergi.v18i2.2627.
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The development of population from time to time is increased and the need for electricity consumption is also increased. Simultaneously increasing the need for electric power requires the provider of electricity supply in this case PT. PLN (Persero) should deliver power effectively to consumers. To maximize the distribution of electricity to the consumer, a load planning is required. This load planning is conducted to find out how much amount of power is required by consumer. The purpose of this research is to investigate the need of power load of interconnection system of South Sulawesi and to investigate the accuracy of load planning using Artificial Neural Network (ANN) backpropagation.
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Austin, Oshin Ola. "Advanced Control And Development of Hydro and Diesel Generator Hybrid Power System Models for Renewable Energy Microgrids." Journal La Multiapp 2, no. 3 (August 11, 2021): 16–32. http://dx.doi.org/10.37899/journallamultiapp.v2i3.383.
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The Nigerian power problem resulted to incessant and erratic supply of electricity and this has destroyed many industrial processes in the country. It has reduced productivity and has increased unemployment rate in the country to over 50million (this figure is over 70% of Nigerian youths). This has led many of the youths in the country to crime. It has led to the deaths of many innocent people in the country. As of 2016, the electricity energy consumption in the world from the world fact book revealed that the average power per capita (watts per person) in the United States is 1,377 Watts. In Canada, it is 1704 Watts per person and in South Africa; it is 445 Watts per person and in Australia, average power per capita (watts per person) is as high as 1,112 Watts. Whereas, the average electricity consumed in watts per person in Nigeria is just 14 Watts. Unfortunately, this has put the country in a rank of 189 out of 219 countries estimated. In this research work, a Hybrid Electric Power System (HEPS) which comprises Hydro Electric Power Plant (HEPP) and Diesel Generator (DG) was modelled and a control algorithm was established to improve the performance of the system. Hybrid power system mathematical and Simulink models were developed. The output power of the developed Simulink model was be optimized using optimum power point optimization techniques and control algorithms. Simulink models of the two components of the Hybrid Electric Power System were produced using MATLAB/Simulink software. The develop Simulink models was interconnected and final model was developed. The results obtained revealed that the problems associated with conventional methods of power generation was overcomed by the development of this renewable and non-renewable energy resources Hybrid Electric Power System (HEPS) models.
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Preston, I. M. H. "Availability of electrical power." Proceedings of the Royal Society of Edinburgh. Section B. Biological Sciences 92, no. 1-2 (1987): 91–106. http://dx.doi.org/10.1017/s0269727000009556.
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SynopsisThe organisation of the generation and supply of electricity in Scotland by the South of Scotland Electricity Board and the North of Scotland Hydro Electric Board is detailed and differences from the other nationalised energy industries in Scotland and from the arrangements for the supply of electricity in England and Wales noted. The present plant position is described and the flexibility in the fuels used underlined. The experiences of the last thirty years are analysed and an account given of the response of the Boards to the crises of dramatic oil price increases and the 1984/85 dispute in the coal industry. Attention is given to the forward planning problems arising from the long construction time of a new station and the delays that may be involved with public inquiries. The opportunities for exporting power to England after the modest anticipated rises in Scottish demands are met are cited as a factor in the budgetting. The difficulties the Combined Heat and Power projects, being studied for a number of major cities including Edinburgh, present to the Boards are listed. Finally the implications for suppliers and contractors of the necessary replacement before the end of the century of equipment associated with the distribution system are noted.
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Zhang, Yechi, Jianzhou Wang, and Haiyan Lu. "Research and Application of a Novel Combined Model Based on Multiobjective Optimization for Multistep-Ahead Electric Load Forecasting." Energies 12, no. 10 (May 20, 2019): 1931. http://dx.doi.org/10.3390/en12101931.
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Accurate forecasting of electric loads has a great impact on actual power generation, power distribution, and tariff pricing. Therefore, in recent years, scholars all over the world have been proposing more forecasting models aimed at improving forecasting performance; however, many of them are conventional forecasting models which do not take the limitations of individual predicting models or data preprocessing into account, leading to poor forecasting accuracy. In this study, to overcome these drawbacks, a novel model combining a data preprocessing technique, forecasting algorithms and an advanced optimization algorithm is developed. Thirty-minute electrical load data from power stations in New South Wales and Queensland, Australia, are used as the testing data to estimate our proposed model’s effectiveness. From experimental results, our proposed combined model shows absolute superiority in both forecasting accuracy and forecasting stability compared with other conventional forecasting models.
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Gore, B. J., G. Gericke, and W. Delport. "PISCES: power industry integrated systems, chemical emissions study." Water Science and Technology 39, no. 10-11 (May 1, 1999): 361–66. http://dx.doi.org/10.2166/wst.1999.0683.
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Power industry chemical emissions study (PISCES) is a broad based study conducted by EPRI in the USA with input from utilities in the USA and other parts of the world. It aims to define the source, distribution, composition and fate of toxics in power plant process and waste streams. Eskom is partaking in this project to develop knowledge of trace element emissions from the power stations which will provide Eskom with sufficient information to determine the concentration levels of toxic trace element emissions from the power stations. From this, the fate of these emissions and their impacts on the environment can be determined. This paper is a report on the first sampling project conducted in South Africa at one of Eskom's power stations. The total study will involve sampling at other power stations and a risk analysis of the fate of the toxic elements emitted. This total study will be completed in 1999.
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Oseni, A. E., and A. S. Durowoju. "Application of GIS in Electricity Distribution: A Case Study of part of Ashamu Layout Kosobo, Oyo East Local Government Area, Oyo State Nigeria." Nigerian Journal of Environmental Sciences and Technology 4, no. 2 (October 2020): 370–81. http://dx.doi.org/10.36263/nijest.2020.02.0106.
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Due to the natural limitations faced by the old system of keeping, planning and managing the distribution of electricity, a computerized system is developed for Power Holding Company of Nigeria (PHCN), on Ashamu Layout of Kosobo Area, Oyo State, Nigeria. Data was acquired using south total station (NTS) and the data was downloaded using NTS.comp and project boundary was plotted with AutoCAD civil 3D, 1m Ikonos resolution satellite imagery was downloaded and geo-referenced with Arcgis10.1. Spatial features such as roads and buildings were vectorized. Electricity distribution and management was designed and created using relational database management system (rdbms) approach. The raster image was added as layer to ArcGIS 10.1 environments for geo-referencing and vectorization. The roads, buildings, electric poles were vectorized and a south total station was used to acquire co-ordinates of the electric poles and transformers to their position on the imagery, creating spatial database for the study area. The developed system was tested by carrying out spatial analysis and spatial search using ArcGIS 10.1. The results obtained were displayed in graphics and tables. It was established from the result that Geographic Information System (GIS) has the capacity as an effective tool for management of electricity distribution system.
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Jamil Ddamulira Mujuzi. "Electricity Theft in South Africa: Examining the Need to Clarify the Offence and Pursue Private Prosecution?" Obiter 41, no. 1 (April 1, 2020): 78–87. http://dx.doi.org/10.17159/obiter.v41i1.10549.
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Electricity theft is one of the challenges with which South African government-owned power-distribution company Eskom is grappling. Eskom has lost billions of rands in annual revenue owing to electricity theft. Different strategies are in place to combat electricity theft. However, in South Africa, electricity theft is not a statutory offence. This contrasts with the approach adopted in countries such as China, Canada, India, Australia and New Zealand, where legislation provides for such an offence. Although electricity theft is not a statutory offence, prosecutors would like electricity thieves to be punished. In this context, there are conflicting High Court decisions on whether electricity theft is a common-law offence or indeed an offence at all. The purposes of this article are: to highlight the problem of electricity theft in South Africa and the conflicting jurisprudence from the High Court on whether electricity theft is an offence; to recommend that Parliament amend legislation to criminalise electricity theft specifically; and also to empower Eskom to institute prosecutions against those who are alleged to have stolen electricity.
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Wintoft, Peter, Ari Viljanen, and Magnus Wik. "Extreme value analysis of the time derivative of the horizontal magnetic field and computed electric field." Annales Geophysicae 34, no. 4 (May 2, 2016): 485–91. http://dx.doi.org/10.5194/angeo-34-485-2016.
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Abstract. High-frequency ( ≈ minutes) variability of ground magnetic fields is caused by ionospheric and magnetospheric processes driven by the changing solar wind. The varying magnetic fields induce electrical fields that cause currents to flow in man-made conductors like power grids and pipelines. Under extreme conditions the geomagnetically induced currents (GIC) may be harmful to the power grids. Increasing our understanding of the extreme events is thus important for solar-terrestrial science and space weather. In this work 1-min resolution of the time derivative of measured local magnetic fields (|dBh∕dt|) and computed electrical fields (Eh), for locations in Europe, have been analysed with extreme value analysis (EVA). The EVA results in an estimate of the generalized extreme value probability distribution that is described by three parameters: location, width, and shape. The shape parameter controls the extreme behaviour. The stations cover geomagnetic latitudes from 40 to 70° N. All stations included in the study have contiguous coverage of 18 years or more with 1-min resolution data. As expected, the EVA shows that the higher latitude stations have higher probability of large |dBh∕dt| and |Eh| compared to stations further south. However, the EVA also shows that the shape of the distribution changes with magnetic latitude. The high latitudes have distributions that fall off faster to zero than the low latitudes, and upward bounded distributions can not be ruled out. The transition occurs around 59–61° N magnetic latitudes. Thus, the EVA shows that the observed series north of ≈ 60° N have already measured values that are close to the expected maxima values, while stations south of ≈ ° N will measure larger values in the future.
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Clark, S., J. L. Van Niekerk, J. Petrie, and S. Fakir. "South African shale gas economics: Analysis of the breakeven shale gas price required to develop the industry." Journal of Energy in Southern Africa 32, no. 1 (February 22, 2021): 83–96. http://dx.doi.org/10.17159/2413-3051/2021/v32i1a8938.
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Is Karoo shale gas an economically viable option for providing the gas needed for the South African power grid? Dispatchable power generation is essential for the implementation of a renewable based electric grid system. Natural gas-fuelled generation is proposed to meet this need, with the gas being sourced from the Karoo. However, no exploration has been conducted on this resource and it is not known if it can be produced economically. Based on information from shale developments in other parts of the world and using publicly available information, this analysis calculates the likely price that this gas would require to be economically viable. The likely steps in the process to get to commercial development would be a baseline survey period, a period of exploration and appraisal drilling, followed by a pilot development. The extensive exploration programme would take about four years and likely cost over USD 450 million. This would be followed by a pilot production programme costing approximately USD 180 million. Once commercial development is achieved, a price for the gas of USD 13.67 per GJ would be required. There are a number of factors, including well recovery, well costs, royalties and operating costs that could add to this price and make this gas development less attractive.
Highlights
South Africa has significant shale gas potential in the Karoo.
Internationally, LNG delivered prices are currently below USD 10 per GJ.
South Africa shale gas breakeven price would be over USD 13.7 per GJ.
An extensive and expensive exploration programme is required prior to development.
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Mabaso, R. G., and A. O. Oduntan. "Refractive status primary school school children in Mopani district, Limpopo Province, South Africa." African Vision and Eye Health 65, no. 4 (December 19, 2006): 125–33. http://dx.doi.org/10.4102/aveh.v65i4.263.
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This article reports part of the findings of a study carried out to determine the causes, prevalence, and distribution of ocular dis-orders among rural primary school children in Mopani district of Limpopo Province, South Africa. Three hundred and eighty eight children aged 8 to 15 years were randomly selected from five randomly selected schools. Non-cycloplegic retinoscopy and auto-refrac-tion were performed on each child. The preva-lence of hyperopia, myopia, and astigmatism was 73.1%, 2.5% and 31.3% respectively. Hyperopia (Nearest spherical equivalent power (FNSE) ranged from +0.75 to +3.50 D for the right and left eyes with means of +1.05 ± 0.35 D and +1.08 ± 0.34 D respectively.Myopia (FNSE) ranged from –0.50 to –1.75 D for the right eye and –0.50 to –2.25 D for the left eye with means of –0.75 ± 0.55 D and –0.93 ± 0.55 D respectively. Regression model for myopia, shows that age had an odds ratio of 1.94 (1.15 to 3.26), indicating a significant increased risk of myopia with increasing age. Correcting cylinders for the right eyes ranged from –0.25 to –4.50 D (mean = −0.67 ± 0.47 D) and for the left eyes from –0.25 to –2.50 D (mean = −0.60 ± 0.30 D). With-the-rule (WTR) astigmatism (66.5%) was more common, followed by against-the-rule (ATR)astigmatism (28.1%) and oblique (OBL) astigmatism (5.4%). With-the-rule astigmatism was more common in females than males; ATR astigmatism and OBL astigmatism werecommon in males. Regular vision screening programmes, appropriate referral and vision correction in primary schools in Mopani district are recommended in order to eliminate refractive errors among the children.
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Amrita, A. A. N., W. G. Ariastina, and I. B. G. Manuaba. "Study of Transformer Lifetime Due to Loading Process on 20 KV Distribution Line." Journal of Electrical, Electronics and Informatics 2, no. 2 (August 31, 2018): 25. http://dx.doi.org/10.24843/jeei.2018.v02.i02.p01.
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Power transformer is very important in electric power system due to its function to raise or lower the voltage according to its designation. On the power side, the power transformer serves to raise voltage to be transmitted to the transmission line. On the transmission side, the power transformer serves to distribute the voltage between the main substations or down to the distribution voltage. On the distribution side, the stresses are channeled to large customers or lowered to serve small and medium customers. As the power transformer is so importance, it is necessary to protect against disturbance, as well as routine and periodic maintenance, so that the power transformer can operate in accordance with the planned time. Some factors that affect the duration of the power transformer is the ambient temperature, transformer oil temperature, and the pattern of load. Load that exceeds the maximum efficiency of the transformer which is 80% of its capacity will cause an increase in transformer oil temperature. Transformer oil, other than as a cooling medium also serves as an insulator. Increasing the temperature of transformer oil will affect its ability as an isolator that is to isolate the parts that are held in the transformer, such as iron core and the coils. If this is prolonged and not handled properly, it will lead to failure / breakdown of insulation resulting in short circuit between parts so that the power transformer will be damaged. PLN data indicates that the power transformer is still burdened exceeding maximum efficiency especially operating in the work area of PLN South Bali Area. The results of this study, on distribution transformers with different loads, in DS 137, DS 263 and DS 363, show that DS 363 transformer with loading above 80% has the shortest residual life time compared to DS 263 and DS 137 which loading less than 80%.
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Kang, SeokJu, Jaewoo Kim, Jung-Wook Park, and Seung-Mook Baek. "Reactive Power Management Based on Voltage Sensitivity Analysis of Distribution System with High Penetration of Renewable Energies." Energies 12, no. 8 (April 19, 2019): 1493. http://dx.doi.org/10.3390/en12081493.
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The high penetration of distributed energy resources (DERs) in the distribution system brings new challenges related to voltage variations and reverse power flow. The sudden changes in electric power generation from the DERs due to climate conditions or their internal malfunction might cause high fluctuations in system voltage. To enhance the voltage stability when a disturbance occurs, this paper proposes a new reactive power management method to control each DER based on voltage sensitivity analysis. The voltage variation has the different features in both steady-state and transient conditions. In particular, its transient behavior depends on the type of DERs. Therefore, the particular optimal control for improving the dynamic response of voltage is difficult to apply for all types of DERs. In contrast, the voltage variation in steady-state can be controlled with the reactive power management by the sensitivity analysis between reactive power generation and system voltage. Even though this paper focuses on the reduction of voltage variation in steady-state, the relationship between the voltage variations in steady-state and transient conditions is also analyzed. The effectiveness of the proposed method is verified with several case studies on the practical distribution system in South Korea by using the time-domain simulation based on the PSCAD/EMTDC software. The results show that the proposed reactive power management method can improve the dynamic voltage responses in both steady-state and transient conditions when the distribution system has the high penetration of renewables.
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Madolo, S. D., A. Telukdarie, and A. Kumar. "Energy–water and GHG nexus: A South African water industry case." Water Practice and Technology 13, no. 3 (September 1, 2018): 673–91. http://dx.doi.org/10.2166/wpt.2018.073.
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Abstract Water and energy are resources that are dependent on each other. Water is needed for the production of energy for fuel extraction, cooling power plants, and processing of fossil fuels. In water cycles, energy is needed for pumping, treatment and distribution of water and wastewater to and from customers. In South Africa (SA), the energy used in the water industry is generated mostly from fossil fuels, which has a significant negative impact on the environment. This research reviews a representative subset of the SA water industry to evaluate energy efficiency and harmful gas emissions optimisation potential. The first component of this study involves a review of the current energy efficiency potential in water distribution systems in SA. On the basis of a literature review, three technologies/practices were identified as being imperative in optimising water utilities in SA. The second part of this study involves the implementation of some performance indicators that illustrate the interdependence of water loss, energy consumption and CO2, NOX and SOX emissions. These indicators are used to compare a few possible mitigation scenarios involving water loss reduction and increasing the system's energy efficiency. The third component of research is developing a novel multi-layered structural water distribution system model by incorporating 29 metrics extracted from the literature reviewed. Analysis of this model is then conducted using a MULTI-MOORA (Multi-Objective Optimization by Ratio Analysis) technique accompanied by a Triangular Fuzzy Number set. The aim of this was to assist water utility managers to identify the most influential performance indicators for attaining the nexus objectives.
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Apeh, Oliver O., Ochuko K. Overen, and Edson L. Meyer. "Monthly, Seasonal and Yearly Assessments of Global Solar Radiation, Clearness Index and Diffuse Fractions in Alice, South Africa." Sustainability 13, no. 4 (February 17, 2021): 2135. http://dx.doi.org/10.3390/su13042135.
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The constant scheduled load shedding in South Africa has commonly been executed in an attempt to maintain the long aging coal power plants in the country. With the rise in the reduction of fossil fuels, efforts to eradicate environmental hazards of carbon through solar photovoltaic (PV) resources to their complete prospect are in progress. South Africa, and in particular the town Alice, acquires sunshine annually, making it appropriate to harvest solar energy. This work aims to characterize solar radiation, clearness index (Kt), and diffuse fraction (Kd) in Alice, South Africa. Hourly global and diffuse solar irradiance were estimated into monthly, seasonal, and yearly variations of Kt and Kd for the years 2017–2020. The range of values for describing the daily classification of sky condition was centered on earlier studies. The cumulative frequency and frequency distribution of daily Kt was analyzed statistically in an individual month. The analyses show that the average percentage frequency of Kt within the period is 11.72% of the cloudy days, 57% of partially cloudy days, and 31.28% of clear sky days. The findings of this research show that Alice remains a key contender for solar energy conversion location, owing to its reasonably high frequency (Kt > 0.40) of clear and partially cloudy skies. Hence, it is essential to establish energy-efficiency for energy consumption and also for daily performances.
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Ogunbanjo, Gboyega A. "Social determinants of health: time for action." South African Family Practice 59, no. 4 (August 28, 2017): 4. http://dx.doi.org/10.4102/safp.v59i4.4732.
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By the time, you receive this issue of the journal, the joint 5th WONCA Africa and 20th South African Academy of Family Physicians conference would have ended in Pretoria South Africa on 20 August 2017. The theme of the joint conference forms the basis of this editorial. So what is “Social Determinants of Health (SDH)”? The World Health Organization (WHO) defines it as the conditions in which people are born, grow, live, work and age. These circumstances are shaped by the distribution of money, power and resources at global, national and local levels. The SDH are mostly responsible for health inequities – the unfair and avoidable differences in health status seen within and between countries. It is acknowledged that “health equity and social determinants” are critical components of the post-2015 sustainable development goals (SDG) global agenda and of the push towards progressive achievement of universal health coverage (UHC). If we have to reduce health inequities, the approach will be to address both SDH and UHC in an integrated and systematic manner.1
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Agung Budhi Udiana, I. Dewa Gde, I. G. Dyana Arjana, and Tjok Gede Indra Partha. "STUDI ANALISIS KOORDINASI OVER CURRENT RELAY (OCR) DAN GROUND FAULT RELAY (GFR) PADA RECLOSER DI SALURAN PENYULANG PENEBEL." Majalah Ilmiah Teknologi Elektro 16, no. 2 (August 31, 2017): 37. http://dx.doi.org/10.24843/mite.2017.v16i02p07.
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Short circuit causing over current problem and can might causing interference of the equipment performance such as distribution transformers also causing widespread disruption occurred. In resolving such interference is required as protection system on the distribution system. Seeing all above is needed coordination between the supporting component of the protection system which is consisted of Over Current Relay (OCR) and Ground Fault Relay (GFR). The research was conducted at PT. PLN (Persero) South Bali Area Network, INDONESIA on recloser in the feeder line of Penebel. OCR setting between the Relay feeder of Penebel, Recloser Celagi, Recloser Bakisan, and Recloser Benana still less selective, with time value coordination between average security was still less than 0,2 second. Then OCR setting and GFR relay feeder of Penebel, Recloser Celagi, Recloser Bakisan, and Recloser Benana was recommended for re-setting in order to minimize disruption and electric power distribution system to be reliable.
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Bradlow, Benjamin H. "Weapons of the Strong: Elite Resistance and the Neo-Apartheid City." City & Community 20, no. 3 (February 24, 2021): 191–211. http://dx.doi.org/10.1177/1535684121994522.
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Transitions to democracy promise equal political power. But political ruptures carry no guarantee that democracy can overcome the accumulated inequalities of history. In South Africa, the transition to democracy shifted power from a racial minority in ways that suggested an unusually high probability of material change. This article analyzes the limits of public power after democratic transitions. Why has the post-Apartheid local state in Johannesburg been unable to achieve a spatially inclusive distribution of public goods despite a political imperative for both spatial and fiscal redistribution? I rely on interviews and archival research, conducted in Johannesburg between 2015 and 2018. Because the color line created a sharp distinction between political and economic power, traditional white urban elites required non-majoritarian and hidden strategies that translated their structural power into effective power. The cumulative effect of these “weapons of the strong” has been to disable the capacity of the local state to countervail the power of wealthy residents’ associations and property developers. Through these strategies, elites repurposed institutional reforms for redistribution to instead reproduce the city’s inequalities.
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Boudia, Sidi Mohammed, Abdelhalim Benmansour, and Mohamed Abdellatif Tabet Hellal. "Wind Energy Resource Assessment at Tindouf Region, Extreme Southwest of Algeria." Applied Mechanics and Materials 541-542 (March 2014): 972–76. http://dx.doi.org/10.4028/www.scientific.net/amm.541-542.972.
Full textAbstract:
In this paper, with the help of two-parameter Weibull distribution, the monthly, seasonal and annual assessment of wind energy potentiality was made using the wind speed data collected in the last decade, from 2001 to 2010 for the meteorological station of Tindouf region. The vertical extrapolation of Weibull parameters and mean wind speed at a height of 50m and the analysis of temporal energy efficiency using a wind turbine of 600kW rated power from Fuhrländer manufacturer was made. The results show that Tindouf situated in extreme Algerian southwest, in the natural region of the Sahara, on the border with Morocco (west), the non-autonomous territory of Western Sahara (south-west) and Mauritania (south), is one of windiest region in the country, swept by local winds with a good annual mean wind speed =5.67m/s and an annual mean wind power density equal to 200W/m2at 10m, while the highest monthly wind energy produced may be reached in May, the seasonal in Spring and the annual gross electric energy produced is equal to 1.85GWh/year.