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The world depends upon coal for much of its energy, yet coal had developed a reputation for being “dirty” and polluting. The reputation seems undeserved; coal can be, and often is, burned cleanly. There are concerns about various emissions, particularly sulphur and nitrogen oxides and mercury, but the impact of these emissions seems overstated, so that statutory control levels are set to unnecessarily...
Deforestation has significantly affected availability of reliable low cost energy resources in low income rural households. As a result, off grid communities are becoming less and less reliant on round wood for energy. However, large amounts of agricultural and forestry residues that are produced annually are destroyed in perennial veld fires and some are deliberately destroyed to prepare for new...
There is a genuine opportunity for the developing world and vulnerable and low-income communities to leapfrog the conventional paradigm of power. Where conventional electricity is reliant on expensive, polluting and centrally controlled generation (with its spider web of infrastructure and dependence on decades-old technologies), the developing world can harness modern, low carbon, renewable, agile,...
This paper gives preliminary results on the energy audit being conducted on Mangosuthu University of Technology (MUT) building facilities, by the Centre for the Development of Green Technologies. The aim of the project is to identify possible areas of energy wastage on campus in order to reduce cost associated with electrical energy consumption. To achieve this, A PEL 103 Power & Energy data logger...
The platinum price has decreased nearly 42% since 2010, forcing platinum mines to reduce expenses in order to remain profitable. Electricity consumption is a large capital expenditure for the mining sector and efforts should thus be made to reduce energy consumption while maintaining production. Compressed air networks were identified as a large energy consuming section in the mining industry. Inefficiencies...
Manually controlled compressed air networks are operated inefficiently. A need exists to reduce the electricity cost of a mining complex by optimising the control of the compressed air network. One way to achieve this is by controlling the compressed air supply to accurately match the demand. A locally developed Dynamic Compressor Selector (DCS) controller was improved to better control complex compressed...
With the decline in productivity in the mining industry it is crucial to reduce operational costs while still maintaining safe underground working conditions. A load shifting project was implemented on the refrigeration system of Mineshaft A as part of a demand side management (DSM) initiative. The DSM project over-performed by 0.5 MW, but an increase in service water temperature was measured over...
Mine cooling and ventilation systems ensure favourable working conditions underground. Mines are hesitant to reduce the Bulk Air Cooler (BAC) water flow as doing so raises safety concerns. Previous studies on this topic compared the measured wet-bulb temperatures to the maximum allowable wet-bulb temperature of 27.5°C. This paper investigates how the temperature of the underground network is affected...
Milk cooling is one of the energy intensive processes in the dairy farm and dairy processing. In a dairy farm, the bulk milk cooler (BMC) should cool milk from a temperature of 35°C to a storage temperature of 4°C. Since the BMC is the major equipment used to extract heat from the milk, it is important to understand the efficiency of the system in a bid to reduce demand in dairy farms. This study...
Cool roofs are beneficial for most buildings almost everywhere in the world. They are described as an inexpensive method in order to improve the comfort level in buildings in mild and hot climate and to save energy. However, their cost-effectiveness can vary significantly, depending on climate and local factors. Therefore, the use of simulations with local conditions can provide the clarity required...
Mining is done at great depths in South Africa and the high virgin rock temperatures at these depths result in refrigeration systems being one of the largest electricity consumers on mines. The general operation, control and equipment stance of the refrigeration systems are, however, inefficient and overdesigned and, as a result, several demand-side management (DSM) initiatives have previously been...
Distributed renewable energy competitiveness is becoming a reality in most countries resulting in an increase of installed capacity in both developed and developing countries. Mexico, India, Germany, Zambia and South Africa have experienced the lowest average tariffs for solar photovoltaic (PV) through their competitive bidding processes between 2015 and 2017. In South Africa, the latest competitive...
South Africa plans to implement a carbon tax as a greenhouse gas mitigation measure. Companies therefore need to prepare for the consequences which the proposed tax will have on their operations. At present, the landscape is overburdened by a large quantity of information intended to support the carbon tax, yet specific guidance is limited. This creates uncertainty for stakeholders. In this paper,...
The production of greenhouse gases (GHG) has led to the Earth's surface temperature increasing by an average of 0.6°C in the 20th century. This is partly due to over reliance on fossil fuels. Human activities are estimated to account for about 69% of GHG emissions. There is now an urgent need for alternative fuels, especially renewables such as biomass, to mitigate this. In most of Sub-Saharan Africa,...
The South African industrial sector is under significant financial pressure and need to reduce production costs to remain competitive in the global and local market. Some steel plants use reheating furnaces to reheat materials before hot rolling. These furnaces use industrial fuel gases as an energy source. Process by-product and purchased gases can be used as fuel. Inefficiencies in gas distribution...
Improved efficiency is the task of the hour. Environmental challenges, which include climate change, global warming and greenhouse gas emission have been fuelling the need to increase energy efficiency in electrical rotating machinery. Furthermore, there is a need to establish a level platform for motor manufacturers globally where they can produce electric machines according harmonized standards...
The changes made to Eskom's IDM ESCo model in 2015 forces energy services companies to sustain industrial DSM project performance for thirty-six months. Historically, typical industrial DSM performance declines shortly after the performance assessment period. To help ESCos adapt to the new program, processes were developed to manage the sustainability of industrial DSM project performance. Three separate...
This paper proposes an optimal energy management model for a grid-connected micro-hydrokinetic pumped hydro storage (MHK-PHS) hybrid system supplying the commercial load. The aim of the model is to minimize the energy costs through power-flow control variables and time-of-use (TOU) tariff scheme. The optimization problem will be solved through the use of the linprog solver in the MATLAB's optimization...
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