Search

Current management of solid waste from pulp and paper activities represents an environmental and economic burden worldwide due to pollution emissions. This study investigates the potential of hydrothermal carbonisation (HTC) treatment as a sustainable alternative for producing cleaner and energy-dense solid fuel from paper mill sludge. The effect of process parameters (temperature, reaction time and solid load) on hydrochar fuel formation from paper sludge was evaluated and, for the first time, the paper sludge-derived hydrochar was optimised to maximise the mass yield and calorific value using response surface methodology (RSM). The physicochemical characteristics, thermal fuel behaviour, energy recycling efficiency and electricity generation potential were assessed by proximate and ultimate analysis, thermogravimetry, bomb calorimeter, scanning electron microscopy and process energy assessment. Results showed that hydrochar fuel formation and properties were mainly influenced by the process temperature and residence time, and governed by dehydration and decarboxylation reactions which reduced the atomic H/C and O/C ratios by 35.5% and 64%, respectively. The produced hydrochars presented low sulphur, nitrogen and ash content with a maximum calorific value (HHV) of 22.9 MJ/kg, equivalent to the HHV of coal for commercial utility in South Africa. The HHV of the hydrochar corresponded to a 49.80% increase over the HHV of the initial feedstock. The optimum operating conditions were 231 ± 1 °C and 1.99 h for a hydrochar yield of 74.4% and calorific value of 18.5 MJ/kg. The energy assessment showed that up to 58.34% of the energy produced by hydrochar fuel combustion may be recycled as heat or power, while the remaining 41.66% of the combustion energy could be utilised to sustain the HTC treatment of paper sludge. The substantial water demand was concluded to be a drawback. Thus, water recirculation and the potential to catalyse the HTC reactions to increase overall process efficiency will constitute a future study to make the process more environmentally friendly for industrial-scale application. [Display omitted] • Dehydration and decarboxylation were predominant. • Optimum energy yield of 18.5 MJ/kg and 74.4% hydrochar was achieved under 231 ± 1 °C and 1.99 h. • Higher HTC reaction severity enhanced the physicochemical properties of the hydrochar. • Hydrochars produced have low nitrogen and sulphur (<1%) content. [ABSTRACT FROM AUTHOR]

Renewable energy has emerged as a promising solution to address the challenges of climate change, energy security, and socio-economic development. South Africa, with its abundant renewable energy resources, has made significant strides in the utilization of renewable energy over the past decade. This paper provides a comprehensive review of the progress of renewable energy advancement in South Africa, examining the policies, initiatives, and achievements in various renewable energy sectors. This study explores the country's transition from a heavily coal-dependent energy system to a diversified and sustainable energy mix. It analyses the growth of renewable energy technologies, such as wind power and solar photovoltaic (PV), highlighting the key milestones, challenges, and opportunities. Furthermore, this paper discusses the role of government support, regulatory frameworks, and private sector investments in driving renewable energy deployment in South Africa. Finally, it identifies the prospects and potential areas for further advancement in the renewable energy sector. This review aims to contribute to the understanding of South Africa's renewable energy journey and provides valuable insights for policy-makers, researchers, and stakeholders involved in the sustainable energy transition. [ABSTRACT FROM AUTHOR]

In South Africa, there has been a rapid adoption of solar power, particularly inverter-based solar sources, in low-voltage (LV) networks due to factors such as load shedding, rising electricity costs and greenhouse gas emissions reduction. In residential LV networks, the alignment between solar supply and energy demand is less precise, necessitating larger battery storage systems to effectively utilize solar energy. Residential areas experience peak energy demand in the morning and evening when solar irradiance is limited. As a result, substantial energy storage is important to fully utilize the potential of solar energy. However, increasing inverter-based, customer-generated power creates an imbalance in the utility supply. This is because utility LV supply transformers have three phases, while individual customers have single-phase connections and no load balancing control mechanism. This supply imbalance adversely affects the overall power quality, causing energy losses, damage to devices and other issues. To address these problems, the paper proposes a smart control approach to minimize power imbalances within utility LV supply transformers. The controller uses customer battery storage in residential areas to balance the utility transformer phases. A laboratory model was built to simulate a three-phase low-voltage network with single-phase customers, both with and without a smart controller. The results show that closely monitoring and controlling individual inverters through a central controller can significantly improve the balance of the supply network. [ABSTRACT FROM AUTHOR]

The ageing of coal-fired power stations in South Africa has led to regular power outages. Therefore, the country will need to urgently increase its electricity capacity to meet further energy demand from growing urbanization and population growth. This challenge has increased interest in alternative energy sources, such as renewable energy (RE). South Africa is gradually implementing appropriate renewable energy practices, reducing carbon emissions, cleansing the air, and assuring a more sustainable future. This paper summarizes the availability, current state, and future potential of renewable energy choices in South Africa. This paper also evaluates specific policy measures and government actions aimed at eliminating barriers and increasing renewable energy deployment in the future. It also considers the South African network's specialized techno-economic analysis. The findings show that South Africa is still heavily reliant on coal, with 78% of the current installed capacity coming from coal power in 2022, compared to 9.3% for solar and wind energy. [ABSTRACT FROM AUTHOR]

South Africa possesses extremely rich renewable energy resources, including solar energy and wind energy, in spite of this, South Africa traditionally relies on coal as its primary energy source. Recently, South Africa confronted with severe electricity shortage. With pressure of power shortage and the transition to low- carbon energy, South Africa has been actively promoting the development of renewable energy, aiming to diversify its energy structure. China, as the world's leading country in the development and utilization of renewable energy, has long been committed to helping South Africa achieve renewable energy development. This article reviews the cooperation progress between China and South Africa in renewable energy, and provides an in-depth analysis of the challenges currently faced by both sides. To address such challenges, it is suggested to strengthen the design of top-level cooperation mechanisms, create diverse collaboration platforms, prioritize the exchange and collaboration of scientific talents. This paper aims to provide a typical reference for deepening renewable energy cooperation between China and South Africa. [ABSTRACT FROM AUTHOR]

Since 2008, the South African economy has experienced several power cuts (unplanned or as part of a load-shedding schedule), presumably because of the inability of the electricity supply to cover the demand. This paper examines the impact of such a demand-supply mismatch on the country's economic growth within a production function framework. To do so, we use an Autoregressive Distributed Lag Model (ARDL) for the period 1985 to 2019. The paper finds that a positive mismatch (or surplus) of electricity (supply>demand) boosts economic growth in the long run. This finding provides evidence that supports the necessity of electricity supply expansion and the promotion of energy efficiency measures that both will create a mismatch (surplus) conducive to economic growth. [ABSTRACT FROM AUTHOR]

The relationship between trade and climate change is not a simple linear relationship. In this paper, using the threshold regression model, we estimated the effect of trade on climate change in South Africa. The paper applied the LM test to examine the nonlinear inference approach to test whether nonlinearity existed and if the threshold model was relevant to the study. The results show that when energy use is set as the threshold variable, the relationship between trade and climate change measured as methane is U-shaped. Also, in other models of GHG as climate change indicators, the results show that the effect of trade on climate change is not dynamic. This result supports the idea that high and low trade effects may have different impacts on climate change indicators. It is, therefore, recommended that all exporters in South Africa resort to more innovative environmental mechanisms to reduce the contribution to climate. The suggestion for future studies is to consider exports of different sectors to climate change. This approach will avoid the generalization of exporting firms as the worst emitters. [ABSTRACT FROM AUTHOR]

Stochastic programming has become increasingly vital in energy applications, especially in the context of the growing need for renewable energy solutions. This paper presents a significant advancement in this field by introducing an efficient and robust algorithm for optimally sizing hybrid renewable energy systems. Utilizing a two-stage stochastic programming approach, the proposed algorithm addresses the challenges posed by the unpredictability of renewable energy sources. The proposed solution leverages the three-block alternating direction method of multipliers (ADMM), a cutting-edge technique that facilitates parallel computation and enhances computational efficiency. The distinctiveness of this method lies in its ability to solve complex stochastic optimization problems without compromising the mathematical integrity of the model. This is achieved by applying first-order optimality conditions, ensuring both robustness and efficacy. To demonstrate the practical applicability and superiority of the algorithm, a case study was conducted in a rural area of South Africa. The proposed algorithm was applied to design an optimal hybrid renewable energy system, and its performance was compared against traditional methods such as progressive hedging and Monte Carlo techniques. Results affirm the superiority of the approach, saving approximately 8.16% capital cost when compared to progressive hedging. In addition, the proposed algorithm outperforms the Monte Carlo method both in terms of CPU time and the number of cost function evaluations. [ABSTRACT FROM AUTHOR]

In this paper, we deviate from the existing literature by disentangling the independent variables into their positive and negative changes to capture asymmetric and dynamic multiplier effects of renewable energy and globalization on carbon neutrality targets within the framework of the autoregressive distributed lag (ARDL) model. In doing this, the paper uses South African data for the period 1990 to 2018 and the results show that CO2 emissions respond differently to the positive and negative shocks in renewable energy, globalization, and economic growth. The effect of a positive shock in economic growth is inelastic and positively related to CO2 emissions while a negative shock in economic growth has an elastic and negative effect on CO2 emissions. These results hold for both long-run and short-run periods. In the case of globalization, the positive shock increases CO2 emissions while the negative shock decreases CO2 emissions; although the long-run effect of a negative shock is elastic and insignificant while the short-run negative shock exerts an inelastic and significant effect on CO2 emissions. Furthermore, both the upward and downward shocks in renewable energy consumption transmit a negative effect on CO2 emissions in the long-run and short-run periods. Therefore, the paper suggests among others that to effectively decarbonize the South African economy, the use of subsidies, tax credits, tax holidays, and a host of others on green energy activities need to be enhanced as incentives for promoting cleaner energy production and consumption. [ABSTRACT FROM AUTHOR]

Background: The urgency to pursue sustainable consumption or use energy in a manner that does not negatively impact the environment has become an important theme in recent times. As a major fluctuation in the atmosphere, climate change will be one of the major challenges faced by youth. As a result, there have been a growing number of young South Africans advocating for environmental justice. Surprisingly, their effort has not yielded the expected result as the country continues to emit a high amount of greenhouse gases. The notion of youth may be construed as those between the ages of 15 and 24. The age bracket suggests that the adult lives of this population will be shaped by environmental crises such as famines, vector-borne diseases, and hikes in commodity prices which may impinge on their basic rights to life, health, and property. This development triggers an ancient discourse, what role can youth play towards decarbonization? In other words, which effective avenue could be used by young people for capping emissions? Methods: An analysis of South Africa's energy policy documents relevant to sustainability was conducted through the application of desktop research. We use (inter)national instruments and jurisprudence to understand how a state structure, like the judiciary, could nudge the executive to cap rising green gas emissions. South Africa is used as a case study because of its over-reliance on coal for electricity, and how young people could use the existing legal framework to cap rising emissions. Drawing from existing literature, the paper interrogates the lack of activism around climate litigation and under what conditions this pattern could be reversed in South Africa. Results: The paper found that while litigation has an important role to play in mitigating climate change, it ought to be complemented with other forms of advocacy. Conclusions: The study concludes that given the government's perceived slow steps towards shifting from coal to renewables, youth (who will bear the brunt of high emissions) ought to use both courtrooms and advocacy to trigger political action. [ABSTRACT FROM AUTHOR]

The increase in population and urbanization have resulted in an increase in the number of wastewater treatment plants in South Africa. Although wastewater treatment plants serve a great purpose in the reduction of environmentally threatening contaminants from wastewater, the increase in energy consumption by these plants raises concerns about climate change. Thus, there has been a rise in literature attempting to map the energy consumption of wastewater treatment plants to help decision-making in the search for alternative energy sources to promote self-sufficient wastewater treatment plants. There has been a proposition of capturing energy from sewers to mitigate the greenhouse gas emanating from energy consumption by wastewater treatment plants. Literature has proven that sewers can produce 10 times the energy required to operate wastewater treatment plants with the correct factors considered including the characteristics of the wastewater being treated, the technology used, and the management practices employed. This has resulted in a rise in the number of studies investigating biogas production from wastewater treatment plants. Although sewage has been proven to be able to produce sufficient biogas to support the energy requirements of wastewater treatment plants to go off-grid. There are still challenges in the implementation of self-sufficient wastewater treatment plants especially in developing countries such as technological barriers and capital investments. Therefore, this paper will investigate possible ways of making wastewater treatment plants more energy sustainable. Out of many approaches of making WWTP sustainable (resource recovery and energy efficiency improvements); energy generation is the main focus of this mini review. [ABSTRACT FROM AUTHOR]

Conventional power systems have been heavily dependent on fossil fuel to meet the increasing energy demand due to exponential population growth and diverse technological advancements. This paper presents an optimal energy model and power management of an off-grid distributed energy system (DES) capable of providing sustainable and economic power supply to electrical loads. The paper models and co-optimizes multi-energy generations as a central objective for reliable and economic power supply to electrical loads while simultaneously satisfying a set of system and operational parameters. In addition, mixed integer nonlinear programing (MINLP) optimization technique is exploited to maximize power system generation between interconnected energy sources and dynamic electrical load with highest reliability and minimum operational and emission costs. Due to frequent battery cycling operation in the DES, rainflow algorithm is applied to the optimization result to estimate the depth of discharge (DOD) and subsequently count the number of cycles. The validity and performance of the power management strategy is evaluated with an aggregate load demand scenario of sixty households as a benchmark in a MATLAB program. The simulation results indicate the capability and effectiveness of optimal DES model through an enhanced MINLP optimization program in terms of significant operational costs and emission reduction of the diesel generator (DG). Specifically, the deployment of DES minimizes the daily operational cost by 71.53%. The results further indicate a drastic reduction in CO2 emissions, with 22.76% reduction for the residential community load scenario in contrast to the exclusive DG system. This study provides a framework on the economic feasibility and effective planning of green energy systems (GESs) with efficient optimization techniques with capability for further development. [ABSTRACT FROM AUTHOR]

Climate change is progressing faster than previously envisioned. Efforts to mitigate the challenges of greenhouse gas emissions by countries through the establishment of the Intergovernmental Panel on Climate Change has resulted in continuous environmental improvements in the energy efficiency and carbon emission signatures of products. In this paper, an energy–carbon emissions nexus causal model was applied using the Leontief Input–Output mathematical model for low-carbon products in future transport-manufacturing industries., The relationship between energy savings, energy efficiency, and the carbon intensity of products for the carbon emissions signature of the future transport manufacturing in South Africa was established. The interrelationship between the variables resulted in a 29% improvement in the total energy intensity of the vehicle body part products, 7.22% in the cumulative energy savings, and 16.25% in the energy efficiency. The scope that has been examined in this paper will be interesting to agencies of government, researchers, policymakers, business owners, and practicing engineers in future transport manufacturing and could serve as a fundamental guideline for future studies in these areas. [ABSTRACT FROM AUTHOR]

In this paper, the BASIC (Brazil, South Africa, India, and China) countries, which play an increasingly significant role in combating climate change, are selected as the research objects. First, we investigate the driving factors of the evolution of carbon emissions in the BASIC group from 2000 to 2016. Second, we use the Monte Carlo simulation to analyze the potential evolution trend of carbon emissions in the benchmark scenario, optimization scenario, and enhanced scenario in the BASIC group from 2017 to 2030 to judge whether the countries can achieve their own autonomous contribution goals. Third, we evaluate whether the BASIC INDC can provide practical support for making the global temperature control goals described in the Paris Agreement. The results show that first, the contribution rate of the energy consumption structure and population size to the carbon emissions of the BASIC are low, and the contributions of R&D efficiency, R&D intensity, and investment intensity to the carbon emission change in the BASIC group are more prominent. Second, under the benchmark scenario, Brazil, South Africa, India, and China from the difference between the complete INDC targets respectively is 265.50 Mt, 207.86 Mt, 1034.70 Mt, and 4660.82 Mt. Under the optimization scenario, China could meet the INDC goals. The gap between Brazil, South Africa, and India is 60.06 Mt, 9.50 Mt, and 413.74 Mt, respectively. Under the enhanced scenario, China and South Africa could meet the INDC target, while Brazil and India are 15.69 Mt and 228.28 Mt away from the INDC target, respectively. Third, although the INDC goals of Brazil and India can achieve the carbon reduction allocated under the 2 °C targets, the INDC targets submitted by the BASIC are not enough to reach the carbon reduction allocated under the global 1.5 °C destination; Brazil, South Africa, India, and China's gap is 64.14 Mt, 246.15 Mt, 236.84 Mt, 3399.64 Mt, respectively. Fourth, Brazil, South Africa, and China should increase its R&D on energy-saving and emission reduction technologies, and India should develop reasonable population policies and green economic development policies. [ABSTRACT FROM AUTHOR]

Mitigation of post-occupancy building energy consumption has resulted in the change of building design to utilise ambient weather factors for indoor thermal conditioning and lighting. This has increased the construction of new buildings with large glazing façades and reduced adaptive use of heritage buildings as they are considered not designed to meet modern energy use requirements. This paper evaluates the daylighting performance of a heritage place of instruction and office building. A quantitative research approach based on building information simulation tools was adopted. Autodesk Revit 2021 and Integrated Environmental Solutions Virtual Environment (IESVE) 2021 were used in modelling and simulating the building daylighting performances. The building's annual daylight performance analysed with climate-based daylight modelling shows that points in the analysed spaces were within the UDI300-2000 for more than 50% of the occupied period (07h00 to 17h00) in a year. The sDA300,50% was found to be 100% in most spaces, which is considered a favourable daylit space according to the Illuminance Engineering Society of North America (IESNA). Further, discomfort glare analysis revealed that the building daylight glare is imperceptible, with an average daylight glare probability of 21.2%. The 1:14 window–wall ratio contributes to the building daylighting relative to orientation without constituting visual discomfort. Overall, climate-based daylight modelling revealed that the building's annual daylight level meets the IESNA requirements with an imperceptible daylight glare. [ABSTRACT FROM AUTHOR]

Renewable energy is an important alternative energy source in terms of both sustainable growth and climate change. In this paper, the causality nexus between renewable energy consumption and economic growth is analyzed in 15 emerging countries covering the period from 1990 to 2015. The paper adopts the bootstrap panel causality test which is developed by (Kónya, Econ Model 23:978–992, 2006) to consider the cross-sectional dependence. The results of (Kónya, Econ Model 23:978–992, 2006) prove the validity of the neutrality hypothesis in all countries. Then, we analyze asymmetric causality among the variables. Asymmetric test denotes a causality from negative shocks of economic growth to negative shocks of renewable energy consumption in South Africa, Thailand, and Turkey. Thus, a negative shock in economic growth hampers renewable energy consumption in these countries. Our results demonstrate the consequences of the application of disaggregated data in the analyses. [ABSTRACT FROM AUTHOR]

Labor force participation rate is a strong issue that affect the performance of any economy including South Africa. Sequel to this, this paper accesses the link amid access to electricity consumption and labor force participation rate of male (LFPRM) in South Africa. Using yearly data from 1991-2020. The study employed ARDL technique to evaluate the data. The findings of the study shows that access to electricity consumption (AEC) positively stimulate labor force participation rate of male in the long run while gross domestic product per capita growth impacted negatively on LFPRM in the short-run. The paper recommends that government should ensure that access to electricity consumption is improved and efficient in South Africa in order to boost LFPRM. [ABSTRACT FROM AUTHOR]

This paper empirically investigates the causal relationship between energy prices and economic performance in South Africa by employing the auto-regressive distributed lag (ARDL) bounds test technique for the period 1994 to 2019. The empirical evidence that was reviewed used a different methodology and covered different periods, particularly in the South African context. While previous studies investigated energy prices by examining oil or electricity prices separately, this study combined these prices in the regression model. The ARDL model is capable of detecting hidden cointegration relationships and works even in series that are integrated of different orders. The study established a long-run relationship between the variables. The findings revealed that electricity prices have a significant negative impact on economic growth in the long and short run, while crude oil prices show a significant positive linkage with economic growth in the long and short run. The Granger causality analysis did not establish a causal relationship between energy prices and economic growth in South Africa. However, it pointed to unidirectional causality from both labour productivity and gross fixed capital formation to economic growth. It is thus recommended that the government should take steps to mitigate the effects of high electricity prices on economic growth in South Africa. [ABSTRACT FROM AUTHOR]

Globally energy management has become a challenge and concern due to rapid increase in energy demand and energy security. In South Africa, electricity supply problems has resulted in load shedding and steep increase in electricity cost. The objective of this paper is to optimise the residential electricity consumption by scheduling the household appliances in line with the time of use (TOU) tariffs. This was done through a fuzzy logic electrical energy controller. The optimisation was achieved by varying load consumption per hour. The fuzzy rules were designed to make intelligent decisions considering the time of use tariff, the remaining daily limit and load consumption. The preferred number of days were set by the consumer and the system calculated the daily limit considering the available amount of electricity in smart meter. The findings showed that the fuzzy logic optimised the residential electricity consumption by scheduling the household appliances in line with the time of use (TOU) tariffs. The fuzzy logic may provide a way in which the smart meter could optimise and enhance the electricity user consumption. [ABSTRACT FROM AUTHOR]

There has been a plethora of debate on the link between fiscal decentralization and a drop in carbon dioxide (CO2) emissions, even though the evidence supporting this assertion is relatively sparse. Although the precise nature of this relationship is still up for discussion, economic hypothesis postulates that fiscal decentralization has an impact on environmental sustainability. Some researchers claim that fiscal decentralization could potentially result in a race to the top, while some believe it would lead to a race to the bottom. This analysis intends to shed light on the precise processes by which this connection may work in South Africa between 1960 and 2020 in light of current discussions in environmental and development economics. In contrary to previous studies, this paper employs a cutting-edge dynamic autoregressive distributed lag simulations methodology to evaluate the positive and negative variations in fiscal decentralization on CO2 emissions. Our findings demonstrate the prevalence of the race to the top strategy by illustrating how fiscal decentralization has a bearing on CO2 emissions reduction in the short and long terms. In accordance with the findings, greater fiscal decentralization should be implemented through the transfer of more powers to regional authorities, especially in the realm of environmental legislation considerations, in a bid to preserve South Africa's environmental integrity. By establishing a lower tier of government and defining roles at the federal and provincial divisions, South Africa could adopt strategies to improve green environment in an effort to fulfill the energy-saving tasks of fiscal expenditures. [ABSTRACT FROM AUTHOR]

The Integrated Energy Plan (IEP) was designed to consider South Africa's energy needs from 2015 to 2050, as a guide for energy structural savings and the development of energy policy. The main aim of the Department of Energy is to ensure the security of energy supply. The current energy situation in the country has its gains and challenges. With the growing population and infrastructural development, the country requires prudent measures to meet the country's energy needs for 2020-2050. The country's energy is currently dominated by coal-fired plants, which represent about 70% of the total installed capacity, crude oil contributes about 21%, with only 9% from all other energy sources, including renewables. This paper examines the scope of the IEP framework, key objectives of the IEP, the methodology applied to achieve those objectives, and the projections made for attaining the framework target. The paper further reviews the energy requirements for the key sectors of the economy and analyses the effects of CO2 emissions and the benefits of job creation for the entire period. Despite substantial renewable potential in South Africa, at present it contributes as little as 2% of the energy mix. The global renewable energy policy on CO2 emissions reduction, improvement of energy efficiency and deployment of renewable development are not met in the IEP framework. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic created large disruptions in the energy industry as governments all around the world responded by enforcing lockdowns on 54% of the global population to slow down the spread of the virus. This impacts the energy consumption of the residential sector as policies prevented residents from leaving their homes and accelerated the transition towards remote work environments. The impact of lockdown on South Africa's energy sector is unique to other countries due to its extreme inequalities across the affluence divide and ongoing blackouts that affect the entire country. A case study is performed in George, a region in South Africa with a distribution of wealth and energy inequality typical for South Africa. In this paper, the following questions are answered: (i) How has the lockdown period influenced the total energy consumption of a household? and (ii) To what extent has the lockdown affected energy consumption of households based on wealth and demographics? The results of this study showed that implementing the highest stage of lockdown resulted in wealthy communities increasing their overall energy consumption by 5 percentage points and poor communities by 2.5 percentage points. The findings of this study support the use of local data and insight for the unique difference in behavioural change across different communities for optimal decision making in future pandemics or natural disasters. [ABSTRACT FROM AUTHOR]

As a developing country, South Africa relies on electricity as the most critical amenity needed for development. KwaZulu-Natal (KZN) is one of the nine provinces in South Africa that faces an energy supply challenge. KZN is also the warmest province among them all due to its location. As one of the warmest provinces, solar power could be utilised to assist in dealing with the energy crisis. This paper focuses on the cost uncertainties attributed to the implementation of solar power which will assist in meeting the demand of energy in the region. The unsustainability of energy has led to a near collapse of the region's economy. This study also contributes to improving the scientific implementation of solar power in the region to deal with the unsustainability criteria observed. The employment of Cost Benefit Analysis (CBA) revealed solar power as one of the most reliable renewable energies for planned implementation bases. With the development of the Economical, Methodological and Environmental (EME) strategic framework which addresses all social cohesion of solar power, the early turn around has been seen through the use of cost-benefit analysis (CBA) in the region of KZN. [ABSTRACT FROM AUTHOR]

The paper utilized a panel dataset to investigate the effects of the impact factors, namely, economic growth, energy intensity, energy consumption, urbanisation, passenger vehicles and transport infrastructure investments on carbon emissions (CO2-eq). The transport sector of the main buoyant economic provinces of South Africa for a consecutive period of five years was investigated using STIRPAT models. Carbon emissions coefficient method, (CECM) is made applicable to determine the quantification of the forms of fossil fuels utilized in the transportation sector. The characterized parametric panel dataset for Gauteng, KwaZulu-Natal and Western Cape were assessed from 2016 to 2020 to make objective function determinations. The results indicate that GDP and passenger vehicles contributed largely to CO2-eq emissions, however, the impact varies across the three provinces. Energy intensity and the approach to energy consumption are significant in mitigating carbon emissions, which is due to the possibilities of high fuel efficiency and pollution decrease. The outcome of the research advances climate change mitigation strategy and proffers the required attention to policy makers in South Africa and Africa as a continent. [ABSTRACT FROM AUTHOR]

In this paper, the characteristics of the Excellence in Design for Greater Efficiencies (EDGE) green building certification system in terms of the scope of certification, and environmental and social strategies focused on 6024 units in the 17 EDGE-certified residential buildings in South Africa was investigated. This research analyzed the efficiency of energy, water, embodied energy in materials, and annual CO2 emissions and their contribution to solving housing issues in the given context. This research revealed that the design of EDGE-certified buildings focuses on the "efficiency first" approach and reduced energy and water demand more than on-site energy production. In energy-saving strategies, energy-saving solutions are three times (69.2%) higher than energy-generating solutions (23.1%). The results on resource savings showed that, on average, embodied energy in materials (54%) is the most reduced resource, followed by water (31%) and energy (29.7%). The statistical analysis indicated that there is no statistically significant correlation between energy, water, embodied energy in materials, and CO2 savings with floor areas of the buildings. In addition, this research highlighted how EDGE certification has positively contributed to solving South Africa's resource shortage and affordable housing scarcity problems. [ABSTRACT FROM AUTHOR]

In this paper, an optimal hybrid (wind and grid)-hydrogen energy system (H-HES) is proposed using multi-objective non-dominated sorting algorithm (NSGA-II) optimization. The H-HES consists of the main energy system; wind-energy system (W-ES), which supplies a proton exchange membrane (PEM) electrolyzer via an energy management system (EMS) and a rectifier. In addition, the grid-energy system (G-ES) is available to support the W-ES to meet the PEM electrolyzer's energy demand, and the EMS facilitates control between the W-ES and G-ES. The W-ES is modelled using wind data from Wind Atlas South Africa (WASA) for six Renewable Energy Development Zones (REDZs) in South Africa and their appropriate wind turbine models. The selection of appropriate wind turbine models is guided by the optimal wind turbine variables obtained from NSGA-II corresponding to the optimal H-HES model. The optimal H-HES model is developed using two objective functions: cost of electricity and efficiency, which are minimized and maximized respectively and evaluated using NSGA-II available in Pymoo framework. NSGA-II successfully converges to a Pareto front, and the best solution for the H-HES cost of electricity and efficiency for each wind REDZ is determined by compromise programming; a multi-criteria decision-making technique available in Pymoo. From the optimal cost of electricity and efficiency solutions, optimal variables are successfully obtained for optimal modelling of the H-HES for each wind REDZ. [ABSTRACT FROM AUTHOR]

Previous studies have widely used the aggregate energy consumption in the energy–growth–CO2 emissions nexus, which may not show the relative strength or explanatory power of several energy sources on CO2 emissions. However, less explored in empirical literature are the effects of disaggregated levels of renewable and non-renewable energy sources on environmental quality. This study therefore contributes to fill this important gap for South Africa over the period 1960–2019. Our strategy is distinctively different from previous works in the following dimensions: we employ the recently developed novel dynamic autoregressive distributed lag (ARDL) simulations framework proposed by Jordan and Philips (Stand Genomic Sci 18(4):902–923, 2018) to examine the negative and positive changes in the disaggregated levels of renewable and non-renewable energy sources, trade openness, technique effect, and scale effect on CO2 emissions. Second, we use an innovative measure of trade openness developed by Squalli and Wilson (World Econ 34(10):1745–770, 2011) to capture trade share in GDP as well as the size of trade relative to world trade for South Africa. Third, we use the frequency-domain causality (FDC) approach, the robust testing strategy suggested by Breitung and Candelon (J Econ 132(2):363–378, 2006) which enables us to explore permanent causality for medium-, short-, and long-term relationships among variables under review. Fourth, we employ the second-generation econometric procedures accounting robustly the multiple structural breaks which have been considerably ignored in earlier studies. For South Africa, the key findings are as follows: (i) hydroelectricity and nuclear energy consumptions contribute to lower CO2 emissions in the long run; (ii) the scale effect increases CO2 emissions whereas the technique effect improves it, validating the presence of an environmental Kuznets curve (EKC) hypothesis; and (iii) oil, coal, and natural gas consumptions deteriorate environmental quality. In the light of our empirical evidence, this paper suggests that South Africa's government and policymakers should effectively study the optimal mix of all available energy resources to meet the increasing energy demands while improving the country's environmental quality. [ABSTRACT FROM AUTHOR]

South Africa is one of the most carbon-intensive economies in the world, but it is presently experiencing an energy crisis, as its utility company cannot meet the country's energy demands. The use of renewable energy sources and retiring of coal-fired power stations are two important ways of alleviating this problem, as well as decarbonizing the grid. Repurposing retiring coal-fired power stations for renewable energy generation (RCP-RES) while maintaining energy sustainability and reliability has rarely been researched. This paper proposes macro- and microelements for repurposing retiring coal-fired power stations for renewable energy generation in Camden with the aim of improving power generation through a low-carbon system. In this model, concentrated solar power (CSP) and solar photovoltaics (SPV), in combination with storage technologies (STs), were employed for RCP-RES, owing to their excellent levels of availability in the retiring fleet regions. The simulation results show that the power densities of CSP and SPV are significantly lower compared with retiring a coal-fired power plant (CFPP). Both are only able to generate 8.4% and 3.84% rated capacity of the retired CFPP, respectively. From an economic perspective, the levelized cost of electricity (LCOE) analysis indicates that CSP is significantly cheaper than coal technology, and even cheaper when considering SPV with a storage system. [ABSTRACT FROM AUTHOR]

This paper presents an efficiency analysis of an induction motor with direct torque and flux control at a hot rolling mill in South Africa. Two scenarios were evaluated: 1) where the induction motor was controlled at a constant speed with a variable thickness slab; and 2) where the speed of the induction motor was controlled according to the thickness of the slab. Both scenarios used the speed as reference to control the torque and flux of the induction motor. A comparison on the energy consumption of the induction motor for both scenarios was done by means of a detailed simulation model. The simulation model for this specific case study is explained in detail. The results obtained showed an increase in the efficiency of the induction motor from the original system (scenario 1) to the improved system (scenario 2). Part of this paper provides an overview on hot rolling mills. [ABSTRACT FROM AUTHOR]

In this paper, we argue using smart technologies beyond the grid disrupts the access and use of existing energy sources, with profound impacts on everyday social life. We show how off‐grid smart energy solutions constitute their own politics when considering existing conceptualisations of urban infrastructures in geography and the social sciences. To expose its politics, or "micropolitics", we consider how tensions occur at the interface between infrastructures, where there are additions and modifications. We draw on an empirical example of Qandu‐Qandu, an informal settlement in South Africa, to highlight how the placement, technical capabilities, and flexible financing options associated with off‐grid solar energy create micropolitics with profound implications for everyday life. To conclude, we reflect on the value of using disruptions for understanding and enhancing equity in off‐grid settings, contributing to the broader sustainability transitions narrative, and its "liveliness". [ABSTRACT FROM AUTHOR]

Many countries have submitted long-term strategies to meet the emission goals stated in the Paris Agreement, but few have introduced specific measures or policies to achieve those goals and there is a need to implement specific policies to build a net-zero-emission society. This research quantitatively examines whether it is possible to achieve virtually zero emissions by 2050 in South Africa, Tunisia, and Egypt. Specifically, the study examines what measures could be taken to realize zero emissions from energy sources to implement long-term emission-reduction strategies by using decarbonization scenarios coupled with an accounting-type static simulation model. The model calculates future energy consumption and greenhouse gas (GHG) emissions for various future scenarios and analyses potential GHG emission reductions. The results show the possibility of achieving zero emissions of energy-related CO2 in South Africa, Tunisia, and Egypt in 2050, mainly by introducing renewable energy and carbon capture and storage; they also indicate that maximising the amount of renewable energy installation is the key to achieving zero emissions in all three countries. This analysis demonstrates that this relatively simple model can contribute to quantitative considerations in emissions pathways and projections when countries develop national long-term strategies. [ABSTRACT FROM AUTHOR]

In this study, the nexus between carbon emissions, financial development and energy consumption is investigated for South Africa using annual time series data from 1990 to 2021. The mounting pressure on nations to reduce their carbon footprint has motivated this study. The findings of this study will contribute to establishing economic variables that South Africa can take advantage of in the journey to reducing carbon emissions. Two energy consumption proxies were used, namely, total energy consumption and electricity. Employing autoregressive distributed lag approach to cointegration and error correction (ECM)-based Granger causality test, the study found a unidirectional causal flow from carbon emissions to total energy consumption in the short run and the long run, and no causality was found when energy consumption was measured by electricity. The study also found a unidirectional causal flow from carbon emissions to energy consumption and from energy consumption to financial development in the long run and in the short run. The findings of the study reveal conscious decisions South Africans are making to reduce the carbon footprint coupled with the financial sector ability to design instruments that suit the customer requirements. Policy implications are also discussed. [ABSTRACT FROM AUTHOR]

The debate over the role international trade plays in determining environmental outcomes has considerably generated more heat than light. Theoretical work has been successful in identifying a series of hypotheses linking openness to trade and environmental quality, but the empirical verification of these hypotheses has seriously lagged. This study revisits the dynamic relationship between trade openness and environmental quality in South Africa using time series data over the period 1960–2020. The recently developed novel dynamic autoregressive distributed lag (ARDL) simulation framework has been used. The outcomes of the analysis indicate that (i) trade openness deteriorates environmental quality in the long run, although it is environmentally friendly in the short run; (ii) the scale effect increases CO2 emissions, whereas the technique effect contributes to lower it, thus validating the presence of an environmental Kuznets curve (EKC) hypothesis; (iii) energy consumption, foreign direct investment, and industrial value-added contribute to environmental deterioration; (iv) technological innovation improves environmental quality; (v) the pollution haven hypothesis (PHH) exists; and (vi) InSE, InTE, InOPEN, InEC, InFDI, InTECH, and InIGDP Granger-cause InCO2 in the medium, long, and short run suggesting that these variables are important to influence CO2 emissions. In light of our empirical evidence, this paper suggests that the international teamwork to lessen carbon emissions is immensely critical to solve the growing trans-boundary environmental decay and other associated spillover consequences. [ABSTRACT FROM AUTHOR]

There are many studies on the relationship between energy consumption and various environmental indicators in Africa, and SANE countries in particular. However, there is a dearth of studies that relate external debt to CO2 emissions, and even the ecological footprint, which is a more comprehensive environmental indicator. As such, this paper applies advanced estimation techniques to explore the role of external debt in the famous energy-growth-environmental nexus in SANE countries from 1970 to 2018. The findings from the Augmented Mean Group estimator indicate that economic growth and energy consumption increase environmental pressure in the SANE countries. On country-level results, the environmental Kuznets curve (EKC) hypothesis, monotonic increase, and monotonic decrease for ecological footprint holds in South Africa, Algeria, and Nigeria, respectively. Also, the results reveal that external debt increases the ecological footprint in South Africa and Algeria. Furthermore, the Kónya (2006) bootstrap country-level Granger causality test shows that ecological footprint is sensitive to economic growth and energy consumption in South Africa and Nigeria, while economic growth is sensitive to the ecological footprint in both Algeria and Nigeria. This study argues that stringent policy suggestions should be centred on reducing the overdependence on non-renewable energy sources since it underscores the major deteriorating state of environmental quality across SANE countries. [ABSTRACT FROM AUTHOR]

The energy sector in South Africa is highly driven by coal, making the country one of the highest greenhouse gas (GHG) emitters in the world. As one of the signatories to the UN Framework Convention on Climate Change, the country is determined to reduce its carbon footprint. In this paper, the role of green hydrogen produced from renewable energy sources to the South African energy sector is presented with the objective of increasing the share of renewable energy in the country's energy mix. First, an overview of the South African energy sector is presented with the aim of pointing out the energy inputs and the usage patterns. Thereafter, the potential of renewable energy resources that could support green hydrogen production is highlighted. Some of the key findings show that 67% of total primary energy sources in South Africa is coal. Industrial and residential sectors account for the bulk of energy usage with 53% and 19%, respectively. It is also revealed that industrial and transportation sectors account for 51% and 38%, respectively, of GHG emission with the residential sector contributing only 2%. The renewable energy resources in South Africa are encouraging for green hydrogen production. Solar has an average 2500 h of sunshine per year with daily total solar irradiation between 4 and 6.5 kWh/m2 day. The annual average wind speed ranges from 5.6 to 8.7 m/s with power density between 218 and 693 W/m2 at 10 m anemometer height in the coastal region of the country. The biomass potential is estimated as 83.91 Teragram per annum with hydropotential of 4.851 GW. This paper is important as it will serve as a firsthand scientific information for optimal development and investment in green hydrogen production in South Africa. [ABSTRACT FROM AUTHOR]

This research investigates the asymmetric impact of renewable electricity energy usage and industrialization on the environmental sustainability of South Africa. The load capacity factor (LF) is a more extensive measure of environmental deterioration when compared to carbon emissions and the ecological footprint, which cover a range of both the demand on and supply of nature. The series dataset used for the empirical analysis spans between 1990 and 2019. The study also investigates the effect of human capital, industrialization, and economic growth on load capacity factor. The result of the NARDL estimator reveals that the increase in renewable electricity energy usage increases LF in the long and short term. However, the decline in renewable electricity energy usage has a neutral impact on LF. Furthermore, the results indicate that industrialization and economic growth impact LF negatively. Lastly, human capital improves environmental quality due to the increasing effect on LF. The spectral Granger causality approach outcomes show that all the parameters can forecast load capacity factors in the long term. Some policy implications, restrictions, and potential future study pathways have been explored in light of this paper's results. • The nonlinear autoregressive distributive lag is employed. • Asymmetric impact of renewable electricity consumption on environmental sustainability. • A broad environmental indicator is used, load capacity factor. • The positive change in renewable electricity consumption promotes environmental sustainability. [ABSTRACT FROM AUTHOR]

This paper examines whether technology and energy have a role to play in agriculture value addition in nine sub-Saharan African countries for a sample period between 1981 and 2015. We employ the Autoregressive Distributed Lag modelling technique to examine the relationship among the variables. Models with technology, energy use, and a combination of technology and energy were considered, respectively. Only Nigeria recorded a positive and significant impact of technology on its agricultural value addition in both the short run and long run in the first model. In the second model, energy use positively and significantly influenced agricultural value addition in two countries (Botswana and South Africa) in the short run. However, the long-run coefficients of energy use were found to be positive and significant for Benin and South Africa. In the third model, short-run coefficients of technology were largely positive but statistically insignificant across the countries, while its long-run coefficient was largely positive but only statistically significant for Nigeria. Also, the short-run effect of energy use remained positively significant for Botswana and South Africa as observed in the earlier model. However, its long-run effect was only positive and statistically significant in three countries (Benin, South Africa, and Togo). Thus, the study recommends the need for huge investment in technology and energy use as well as the sensitisation of local farmers in adopting technology to further enhance the quality of their output. [ABSTRACT FROM AUTHOR]

The theme of this paper is to explore the interconnection between financial development, real growth, and urbanization and CO2 emissions using South Africa. The study used a recent econometric technique to investigate this relationship. The data used in this study cover period between 1971 and 2016. No previous research has utilized the wavelet coherence method to collect information on the correlation and causal interaction between these economic indicators at various frequencies and timeframes in the case of South Africa. The research objectives were to fix the questions: (i) if there is a stable long-run relationship among the indicators under consideration? (ii) Does financial development, economic growth, and urbanization affect CO2 emissions? (iii) How are the indicators related, at different frequencies and various periods? The outcomes affirm that (i) financial development impacts CO2 emissions positively. (ii) The linkage between urbanization and CO2 emissions is negative. (iii) Positive interaction between real growth and CO2. The results of the wavelet coherence approach support the ARDL long-term estimate. Based on these results, recommendations have been made. [ABSTRACT FROM AUTHOR]

Concerns over climate change are increasingly reaching an urgent level. Many countries have begun focusing their efforts on mitigating its devastating impact. At the same time countries need to ensure their economic growth and development, thus calling for greater energy usage leading to increased greenhouse gas emissions. As the environment struggles to adapt to the rapid changes brought about by climate change, the effects are felt by the most vulnerable of the world's population. Reports from the Intergovernmental Panel on Climate Change have outlined the reasons and the effects of climate change providing actions required to mitigate these effects. Unfortunately developing countries, including South Africa, are the most affected. The current energy system in the country is primarily based on fossil fuels, which emit the greatest amount of greenhouse gases. To ensure that South Africa mitigates the impact, government needs to safeguard and promote sustainable development. To do this South Africa should weigh its energy mix in relation to the environment and the wellbeing of its citizens. A comprehensive and robust regulatory framework on climate change is required thus ensuring the achievement of South Africa's developmental goals well into the future and ensuring participation in the global effort against climate change. Earthlife Africa Johannesburg v Minister of Environmental Affairs 2017 2 All SA 519 (GP) signifies a good start towards the effective regulation of climate change in South Africa. [ABSTRACT FROM AUTHOR]

South Africa faces several development challenges including those linked to climate change. Energy usage in South Africa, for example, is already constrained because of a range of development challenges (the dependence on cheap coal as a heating source; energy availability; access; affordability of alternative energy sources; and a range of health impacts, including air pollution). Notwithstanding calls for a transition to a low carbon economy, there have been few, recent assessments in South Africa of the costs associated with such a transition, particularly the social and economic costs for the poor who use energy in a variety of ways. In this paper we focus on trying to unravel some of the complex energy-use behaviour including understanding what drives consumers in resourcepoor areas to choose and use persistently risky energy options. Analysis of qualitative data in two township areas, Doornkop and Kwaguqa, shows that township households, whether electrified or not, continue to burn coal. In both study areas, an estimated 80% of electrified households burn coal for space heating and cooking and also make use of multiple fuel sources for a range of activities. Although the major obstacles preventing people from discontinuing domestic coal combustion are poverty, the ready availability and social acceptability of coal together with other social customs cannot be underrated. This paper therefore highlights some of the persistent challenges associated with sustainable energy transitions in South Africa including implications for improved mitigation and adaptation for the energy sector in wider climate change efforts. [ABSTRACT FROM AUTHOR]

Climate change is one of the most significant challenges of the 21st century. To combat climate change the international community has agreed to keep the average temperature increase well below 2°C above pre-industrial levels. Despite this consideration, the latest scientific evidence suggests that the planet has already warmed by 1.1°C above pre-industrial levels. The slow reaction by national governments to reducing greenhouse gas emissions has prompted cities to take ownership of climate change mitigation action and drive global intervention from the sub-national level. These urban areas are home to more than half of the world's population and have immense energy requirements, and typically rely heavily on fossil fuels to meet this demand. Therefore, a shift to city level climate governance is significant as cities are both the victims and the culprits of climate change. Should cities supplant fossil fuels with renewable energy initiatives in meeting their energy demands, this would provide a significant boost to climate change mitigation efforts. Bioenergy as a form of renewable energy can potentially contribute to the energy mix in cities through biomass exploitation while simultaneously addressing climate change mitigation efforts. This article focusses on the role of bioenergy in the energy discourse in cities and the potential of law and policy to contribute to developing these biomass-based systems. The article provides insight into the South African bioenergy regulatory framework from an energy and climate change perspective and offers an account of what bioenergy can contribute to cities when considering the transition to a low-carbon economy. [ABSTRACT FROM AUTHOR]

In this paper, the impact of renewable energy consumption on economic growth in South Africa has been examined during the period from 1990 to 2019. The study aims to establish whether or not renewable energy consumption matters in the economic growth process of South Africa. Empirical evidence to date on the renewable energy consumption and economic growth nexus is not only scanty but also inconclusive, calling for a study of this nature. Using the ARDL-bounds testing approach, the study failed to find any significant impact of renewable energy consumption on economic growth in South Africa, irrespective of whether the regression analysis is conducted in the short run or in the long run. The findings of this study, therefore, lend more support to the neutrality hypothesis, where renewable energy consumption has no significant impact on economic growth. Based on these empirical results, we can conclude that energy conservation can be pursued in South Africa without jeopardizing the economic growth efforts of the country. [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO2), whose atmospheric volume has been increasing, is the principal greenhouse gas (GHG) that causes global warming and climate change. Climate change from increasing greenhouse gases (GHGs) has broad health and environmental influences. Human-emitted GHGs constitute a significant cause of global warming. The main objective of this article is to assess the influence of technological innovation, economic growth, fossil energy use, renewable energy consumption, and globalisation on CO2 emissions (CO2Es) in South Africa over the observation period 1990–2020. The Dynamic Ordinary Least Squares (DOLS) estimator was implemented to examine the relationship between the constituents. The study results indicate that economic growth, fossil energy use, technological innovation, and globalisation boost CO2Es, whereas renewable energy consumption reduces CO2Es. The output of the canonical cointegrating regression and fully modified least squares estimators also supports the output of the DOLS estimator. We concluded that, in South Africa, a rise in economic growth, fossil energy use, technological innovation, and globalisation results in an upsurge in CO2Es. In contrast, an increase in renewable energy consumption leads to a reduction in CO2Es. This research work contributes to the discourse on CO2Es in the South African context. The study recommends that policymakers in South Africa should design policies that foster the formation of a low-carbon country, the consumption of renewable energy, and the implementation of environment-friendly technological innovations that reduce the use of fossil energy. Highlights: • This study assessed the impact of economic growth, technological innovation, fossil energy use, renewable energy consumption, and globalisation on CO2Es in South Africa. • The analysis revealed that economic growth, fossil energy use, technological innovation, and globalisation boost CO2Es, whereas renewable energy consumption reduces CO2Es. • There is a need to incorporate policies that promote the development of a low-carbon economy. [ABSTRACT FROM AUTHOR]

Abstract Given the significance of the residential sector in terms of energy consumption, a comprehensive understanding of households’ energy consumption patterns and choices is imperative. This paper focuses on analysing and understanding the South African residential sector's energy characteristics considering their energy-use profile, and other characteristics such as their geographical distribution and demographic characteristics. The findings show that despite poorer households who are connected to the national grid receiving 50 kW/h of free electricity per month to help them cover their basis energy needs, South African households – particularly low-income households – still use various sources of energy including wood and paraffin to satisfy their basic energy requirements. Solid fuels are predominantly used in rural areas where around 75% of non-electrified households rely on solid fuels for cooking, heating and lighting. Low-income South African households consume between 5% and 10% of their total energy in lighting; space heating and cooking account for the remainder 85–90% of their total energy consumption. After evaluating the relevant data regarding households’ access to electricity, the type of energy used by households and households’ expenditure on electricity and energy in South Africa from the NIDS dataset; it was concluded, that electricity access is reasonably high across South African households. Additionally, an increasing trend can be observed in their total expenditure on electricity. However, approximately 70% of households still spend on other energy sources. Highlights • This paper evaluates the evolution and characteristics of energy consumption in the South African residential sector. • Emphasis was given to the behaviour of households in using energy for cooking, lighting and heating. • Around 70% of low-income households rely on sources of energy other than electricity to satisfy their basic energy needs. • Around 10% of low-income households are energy poor and cannot afford using electricity to cover their basic energy needs. • Results from the NIDS dataset indicated that electricity access is reasonably high across South Africa. [ABSTRACT FROM AUTHOR]

This paper presents an assessment of energy performance in South Africa from 1965 to 2014 using the technique for order of preference by similarity to ideal solution (TOPSIS). In this research, TOPSIS is used first in a two-stage approach to assess how energy in South Africa has performed using the most frequent indicators adopted by the literature. Afterwards, in the second stage, neural networks are combined with TOPSIS results as part of an attempt to produce a model for energy performance with good predictive ability. The results reveal different impacts of contextual variables such as the rise of China in foreign trade, the Apartheid Regime, and oil shocks on energy performance in South Africa. [ABSTRACT FROM AUTHOR]

Understanding the connection between water supply and energy consumption in a circular economy is crucial for managing the demands of these resources. Sankey diagrams have the potential to enhance the visualisation of resource flows. However, there is a knowledge gap regarding the effective use of Sankey diagrams to capture the water-energy nexus and circularity of water. This study focused on effectively utilizing Sankey diagrams to model the nexus of water and energy flows and to assess the circularity of water. A comprehensive literature review was conducted on major studies on water material flows and modelling. This was supported by a review of approaches for modelling circularity, which have evolved from the material circularity index. The newly developed framework in this paper models water resource flows at all stages of the water supply chain, embedding the nexus as an interaction and considering resource intensity and material circularity index at each node. A city-level case study in South Africa was then used to apply the recommendations, model circularity, and the water-energy nexus using Sankey diagrams. In terms of circularity, the results indicate that water loss in the study area was very high, accounting for up to 40% of the total water supply and the water recycle rate was still very low, ranging from 3% to 7%. In terms of the nexus, the residential sector was found to have the highest energy intensity for water supply, primarily due to energy demand for water heating. Exploring the use of renewable or solar energy for water heating will be of interest and value. The new approach presented in this study allows for the simultaneous consideration of objectives, enabling a more robust analysis of energy-effective water use and water circularity along the water supply chain. [Display omitted] • A new framework for modelling the water energy nexus enriched by circularity options, energy intensity factors and confidence modelling. • Options for embedded circularity through the water supply chain. • The urgent challenge to address massive water loses in water supply systems for water scarce regions. • New Sankey diagrams showcasing how to model nexus and circularity. [ABSTRACT FROM AUTHOR]

This paper addresses the critical challenge of sizing hybrid renewable energy systems over their lifespan while accounting for uncertainties in energy sources and load demands. By leveraging stochastic programming, we introduce a novel modeling technique that ensures robust optimization without compromising numerical tractability. Unlike conventional methods, which determine system parameters for the entire project duration upfront, our approach enables annual adjustments to the renewable components' sizing. This dynamic strategy alleviates early-stage under-utilization, aligning system capacity with evolving demand patterns. Central to our approach is the reformulation of the two-stage stochastic program as a quasi-optimal control. This reduces the number of optimization variables significantly, simplifying the solution process. Moreover, thousands of constraints are replaced with a system of differential equations, enhancing computational efficiency. By minimizing capital costs and dynamic operating expenses, we achieve an optimal system size. Through a real-world application in a rural area of South Africa, we demonstrate the effectiveness of our approach. The results showed a remarkable improvement in problem-solving efficiency, reduced under-utilization, and heightened adaptability to unpredictable weather conditions. This innovative framework represents a substantial leap forward in hybrid renewable energy systems design, offering a more agile and efficient solution for sustainable energy generation. [ABSTRACT FROM AUTHOR]

Institutions of higher learning in South Africa are grappling with occasional power outages in lecture halls, leading to disruptions in academic activities and occasional loss of lecture hours. Therefore, this study presents a comprehensive evaluation of a grid-connected solar PV/Li-ion battery microgrid (μG) system aimed at maintaining a constant power supply to selected lecture halls at a university in the Western Cape, South Africa. The microgrid design, modelling, and simulations, conducted in the MATLAB/Simulink environment, include the solar PV, Li-ion battery, energy consumption of the lecture halls (load profile), boost converter, bidirectional converter, and grid. Using the detailed design, modelling, and simulation, the study evaluates the economic and environmental impacts of integrating μGs, focusing on enhancing energy reliability, reducing operational costs, and mitigating CO2 emissions. The results indicate that integrating the microgrid resulted in a significant 51% reduction in energy cost and a decrease in greenhouse gas emissions by 530 kgCO2e per hour. In Cases 2 and 4, where the battery supplied power, the annual battery degradation costs are 6.08% and 14.9% of the initial cost, respectively. The μG ensures an uninterrupted power supply and improves the overall reliability of the university's energy infrastructure. It promotes environmental sustainability goals of zero emissions and maintains continuous academic activities during grid outages. Furthermore, it fosters a conducive learning environment, supports innovation and creativity in sustainable energy technologies, and sets a standard for other higher education institutions to integrate renewable energy-powered μGs. [ABSTRACT FROM AUTHOR]

The long-term impact of high-energy consumption in the manufacturing sector results in adverse environmental effects. Energy consumption and carbon emission prediction in the production environment is an essential requirement to mitigate climate change. The aim of this paper is to evaluate, model, construct, and validate the electricity generated data errors of an automotive component manufacturing company in South Africa for prediction of future transport manufacturing energy consumption and carbon emissions. The energy consumption and carbon emission data of an automotive component manufacturing company were explored for decision making, using data from 2016 to 2018 for prediction of future transport manufacturing energy consumption. The result is an ARIMA model with regression-correlated error fittings in the generalized least squares estimation of future forecast values for five years. The result is validated with RSS, showing an improvement of 89.61% in AR and 99.1% in MA when combined and an RMSE value of 449.8932 at a confidence level of 95%. This paper proposes a model for efficient prediction of energy consumption and carbon emissions for better decision making and utilize appropriate precautions to improve eco-friendly operation. [ABSTRACT FROM AUTHOR]

This paper examines the nexus between financial development and energy consumption in South Africa. To determine the long run and short run relationship between financial development and energy consumption in South Africa, the paper uses an Auto Regressive Distributed Lag bounds test (ARDL) and Granger causality test to establish the type of correlation between 1980 and 2018. ARDL bounds testing method offers concrete long-run estimates and t-statistics as it is flexible whether the adopted variables are I(0) or I(1). The study used per capita (kilogram, kg of oil equivalent) to measure total energy consumption, domestic credit to the private sector (percentage of gross domestic product, GDP) to measure financial development, real GDP growth (to capture economic growth), industrial value added (percentage of GDP) to measure industrialization, and urban population (percentage of total population) to capture urbanization. Results from ARDL showed that the relationship between financial development and energy consumption is positive in nature both in short-run and long-run. Granger causality test results revealed unidirectional causality from financial development to energy consumption. Policymakers need to formulate policy reforms that channels more credit to private sector development in order to bolster more energy use in South Africa. There ought to be proper balance between financial development and energy consumption to avoid electricity crisis. [ABSTRACT FROM AUTHOR]