Managing System Losses to Improve Energy Efficiency within the Electricity Company of Ghana (ECG) Limited

The inability to achieve the target of universal access to electricity is influenced by several factors including funding limitations, the use of obsolete equipment, power theft, and system losses confronting the electricity distribution services of the Electricity Company of Ghana Limited (ECG). The study assessed the components of system losses within the ECG by determining and computing the percentage of system losses within ECG, examining the causes of both commercial and technical losses in ECG, and determining ways to improve energy efficiency by reducing system losses in the most cost-efficient manner. The study adopted deductive reasoning and a quantitative approach to guide data collection and analysis of the research output. A sample of 345 technical and non-technical staff of ECG in the Greater Accra Metropolis was selected from a population of 2500. Purposive, simple random, and cluster sampling techniques were used in identifying and accessing respondents for the study. Descriptive statistics were applied to measure central tendency and degrees of dispersion and the Relative Importance Index (RII) to predict criterion and predictor variables. The impact of low voltage network losses can adversely contribute to technical losses (20%) and reduce energy efficiency in power or electricity distribution companies. Non-technical losses are mainly caused by illegal connections, meter problems, and billing problems. Each of the non-technical losses contributes a maximum of 10% to system losses. Contributors to system losses at ECG are ranked first for power theft and least for lack of incentives. System losses at ECG include metering inaccuracies, bad workmanship, unmetered supply, and lengthy distribution lines, each recording a mean value of above 3.5. Measures to improve monitoring of the networks and systems at ECG and discourage power theft should include an extensive quantification, patrolling, and inspection of the entire network to assess the extent of the network and conditions relevant for the placement of systematically planned maintenance programmes.

The Correlation between the Power Quality Indicators and Entropy Production Characteristics of Wind Power+Energy Storage Systems

Power quality improvements help guide and solve the problems of inefficient energy production and unstable power output in wind power systems.The purpose of this paper is mainly to explore the influence of different energy storage batteries on various power quality indicators by adding different energy storage devices to the simulated wind power system,and to explore the correlation between systementropy generation and various indicators,so as to provide a theoretical basis for directly improving power quality by reducing loss.A steady-state experiment was performed by replacing the wind wheel with an electric motor,and the output power qualities of the wind power systemwith andwithout energy storagewere compared and analyzed.Moreover,the improvement effect of different energy storage devices on various indicatorswas obtained.Then,based on the entropy theory,the loss of the internal components of the wind power system generator is simulated and explored by Ansys software.Through the analysis of power quality evaluation indicators,such as current harmonic distortion rate,frequency deviation rate,and voltage fluctuation,the correlation between entropy production and each evaluation indicator was explored to investigate effective methods to improve power quality by reducing entropy production.The results showed that the current harmonic distortion rate,voltage fluctuation,voltage deviation,and system entropy production are positively correlated in the tests and that the power factor is negatively correlated with system entropy production.In the frequency range,the frequency deviationwas not significantly correlated with the systementropy production.

A Review of the Characteristics and Challenges of Electricity Distribution in Ghana: Case Study of the Northern Electricity Distribution Company

This paper presents a review of the characteristics and challenges of electricity distribution in Ghana with an emphasis on the Northern Electricity Distribution Company (NEDCo) in the northern half of Ghana. NEDCo is used as a case study due to the peculiarity of its geographical area of operation and customer characteristics which better highlights the challenges of electricity distribution in Ghana. NEDCo’s electricity distribution operations cover approximately 64% of the total landmass of Ghana and contain the most deprived communities and consumers, who are extensively dispersed. In addition to the scattered settlements, NEDCo has a predominantly lifeline customer base that pay tariffs below the average cost of service. These peculiarities, together with regulatory complexities, have contributed to many challenges, such as high system losses, high cost of service and poor network reliability, in the electricity distribution sector in Ghana.

Investigating the Effects of Slack Bus Selection in Load Flow Studies: A Comparative Analysis of Robust and Weak Grids

Load flow studies play a critical role in the analysis of power systems. They enable the computation of voltage, current, and power flows in a power system. They provide valuable insights into the steady-state performance of the power system under different operating conditions. Choosing a slack bus is a vital step in conducting load flow simulations. A slack bus is a PV bus that includes a generator and is used to balance real and reactive power during load flow studies. Many studies have been conducted on the selection of slack buses in load flow analysis. However, varied conclusions regarding the impact on system losses and power flows were obtained during these studies. Therefore, using the IEEE-14 bus test system, this study investigated the effects of slack bus selection in strong and weak grids by alternating slack buses among PV buses and observing the effects on bus voltage magnitude, bus voltage phase angle, total power flows, and active and reactive power losses. The study noted that the effect of slack bus selection on these system quantities is contingent upon the voltage stability of the grid. Whereas in a robust grid, system losses and power flows remained constant irrespective of the choice of slack bus, a weak grid experienced some variations in these system quantities under similar circumstances. The simulation results led to the conclusion that, to a large extent, the voltage stability of the grid plays a significant role in determining the degree to which slack bus selection affects system losses and other quantities in load flow studies.

A model to determine soiling,shading and thermal losses from PV yield data

Apart from being a clean source of energy,photovoltaic(PV)power plants are also a source of income generation for its investors and lenders.Therefore,mitigation of system losses is crucial for economic operation of PV plants.Combined losses due to soiling,shading and temperature in PV plants go as high as 50%.Much of these losses are unaccounted initially,which can jeopardize the economic viability of PV projects.This paper aims to provide a model to determine losses due to soiling,shading and temperature using quantities like irradiance,cell temperature,DC power and current,which are readily available in PV yield data captured by the remote monitoring system,without involving any additional sensors or equipment.In this study,soiling,shading and thermal losses were calculated using PV yield data obtained from a 30-kWp PV plant located in Kharagpur,India.The results showed soiling and shading losses as high as 25.7%and 9.7%,respectively,in the month of December.Soiling loss was verified by measuring transmittance loss of coupon glasses installed in the vicinity of the plant.Shading loss was verified by shadow simulation using an architectural tool(SketchUp).Array thermal loss obtained using the proposed methodology was found to be in line with the estimated value obtained from PVsyst simulation.Additionally,using time-series data,the energy losses corresponding to soiling,shading and temperature effects were calculated by a numerical-integration technique.The monetary loss due to these energy losses thus obtained provides criteria for deciding when to mitigate the sources of these losses.