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With increasing energy costs and a renewed focus on using energy in ways that support the environment, a structured approach is required to ensure that energy is used efficiently. Knowing the efficiency of installed motors is essential for effective motor energy management. The efficiency data can be used in the identification of opportunities for improving energy efficiency by replacing inefficient...
A slight variance in dataset quality or baseline model accuracy can affect the level of confidence at which DSM project results are calculated. General measurement and verification (M&V) guidelines mitigate this inherent variance by reporting a conservative result. However, it remains important to quantify the magnitude of variance to ensure that the conservative approach does not adversely affect...
The ever-growing human population, limited energy resources and the effect of greenhouse gas emissions have become major global concerns for the energy sector. This includes the electricity generation sector. This dilemma has caused electricity providers to revise their generation methods and created a major need for consumers to utilise electricity more efficiently. Demand Side Management (DSM) is...
Mine-cooling and ventilation energy cost saving projects are implemented ad hoc and scattered throughout the system. Therefore, an overhead view and strategy is needed to help realise the total savings available on the entire mine-cooling and ventilation system. An overview and foundation is given of all the systems forming part of the mine ventilation and cooling system as well as the available energy...
In today's energy crisis, the mining industry has been identified as a promising area for application of energy efficiency techniques. This paper investigates potential for energy/cost saving, by implementation of variable speed drives (VSDs) on ventilation fans underground. In particular, ventilation on demand is considered in the study i.e. in cases when a mine's ventilation demand may vary throughout...
Mine cooling system components are an integral part of a mine's ventilation system. A mine's reliance on these capital intensive components are set to increase as mines deepen. Mine cooling systems consume up to a quarter of the electricity used on mines. Component efficiency should thus be monitored to ensure optimum utilisation. The performance of mine cooling system components is investigated in...
Large energy consumers face mounting pressure due to recent energy cost increases, as well as regulatory requirements and limitations. Therefore, energy performance monitoring is an essential component of many modern businesses. Consumers must manage energy resources sparingly. However, managing the large datasets associated with large-scale operations can often become overwhelming. This creates the...
This research paper looks at developing a new formula and method for investigating and analyzing overall efficiency of a power system containing multiple harmonic sources. Traditionally, the power generated and consumed due to harmonics is ignored in overall efficiency studies. However, in the modern world, power systems contain levels of harmonics which can no longer be ignored. In this paper, five...
This paper presents a study on energy losses in the industrial sector caused by low actual efficiency of induction motors (IMs). The main reasons are discussed and an efficiency analysis of a 3-phase induction motor, commonly used in industry, presented to compare such motors' nominal and actual efficiencies. Based on the difference between nominal and actual efficiency, energy loss is calculated...
This paper presents a model predictive strategy for a three-phase, two-level Voltage Source Inverter (VSI) and three-level Diode-Clamped Converters (DCCs) with AC filter for Renewable Energy Systems (RES) applications. The renewable energy systems model is used in this paper to investigate the system performance when power is supplied to Resistive-Inductive load (RL-load). This strategy allows for...
The increasing interest in space exploration, satellite activities, structural health monitoring and terrestrial monitoring in harsh and inaccessible environments place a high demand for energy sources for autonomous systems. The existing battery technologies that can be utilized for autonomous systems are plagued by short-life, low energy storage density, associated unwanted maintenance burdens of...
The Industrial and Commercial sectors in South Africa consume more than 80% of the electricity generated by Eskom. The generation of electricity to meet the demand in these sectors is primarily derived from the coal thermal power plant. The goal of Eskom is to sustain the demand and equally reduce environmental pollution. Eskom has embarked on energy efficiency initiatives on their coal boiler plant...
The electrical networks are becoming more complex with the introduction of distributed generators; power electronics based control devices and various types of loads. The electrical networks are no longer passive meshed systems, as they were a couple decades ago. Rather the generation, transmission and consumption co-exist almost at all levels of the electrical networks. With the increasing number...
This paper presents preliminary results that were obtained while monitoring the thermal performance of a solar water desalination system. The system consists of a solar collector equipped with evacuated heat pipes which supply the heat from the sun to a circulating fluid in a collective manifold. Data was obtained indoors by the use of a solar simulator during experiments conducted in the Department...
As part of the Demand Side Management (DSM) initiative, Eskom partially funds load management and energy efficiency projects. Large industries are therefore willing participants in the Eskom funded electricity savings programme that hold benefits for all parties. One such industry is the mining sector. The refrigeration and pumping systems used in these sectors are two of the major electricity consumers...
Access to reliable and adequate energy is a compulsory step to industrialization, improving the living standards of the people, enhancing safety and security, and preserving a healthy environment. Energy plays a fundamental role in shaping and reshaping of the human condition and is therefore essential for human survival and a major factor for economic growth. There is a strong correlation between...
In South Africa, more than 40 % of the electricity generated by Eskom is used by the commercial sector. The universities constitute the primary consumers of electrical energy through the utilization of hot water. The research focused on the construction of a data acquisition system that monitored the demand and hot water profiles of a 12.0 kW Calorifier. The DAS comprised of 1 current transducer that...
Compressed air supply and demand strategies have received significant attention since integrated demand management was initiated by Eskom. Due to the expensive nature of this vastly utilised energy carrier, every increase in the efficiency of a system is needed. Usually controlling the compressed air demand resulted in a reduced need for supply, ultimately leading to energy savings. The majority of...
Energy costs are increasing rapidly. Energy efficiency strategies are required to reduce electricity consumption for energy intensive operations. Cooling systems of deep level mines consume approximately 25% of their total electricity consumption. Cold water supplied by these systems is reticulated throughout the mine. Water reticulation can account for a further 42% of the total electricity consumption...
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