ANALYSIS OF TECHNICAL AND NON-TECHNICAL LOSSES IN AN ELECTRICITY DISTRIBUTION SYSTEM

Abstract

ABSTRACT The quality of service delivery from electricity distribution networks (EDNs) despite the huge post-privatization intervention fund provided by the Federal Government of Nigeria is still far from being satisfactory due to aggregate technical, commercial and collection (ATC&C) losses. This study evaluated ATC&C losses in an EDN using FUNAAB 33kV and Obantoko 11kV distribution network feeders as case studies. The weekly data of injected power, energy consumed and energy billed on both feeders were collected from Ibadan Electricity Distribution Company (IBEDC) for a period of six years (2018-2023). The power losses and voltage drops on the feeders were calculated using the formulated power equations comprising the parameters load factor, conductor length, conductor cross-sectional area, conductor resistivity,maximum feeder loading, line voltage and power factor. The billing data were analysed to determine the commercial and collection losses. Physical assessment of the feeders as built was also carried out. The obtained results revealed that the highest power losses of 11.74 and 6.682 MW, respectively, were observed on FUNAAB 33 kV and Obantoko 11 kV feeders. These losses which occurred in the year 2022 corresponded to 5.86 and 10.85% losses in power, of 200.4 and 61.56 MW, respectively, injected into both feeders. The voltage drop on FUNAAB 33 kV feeder over the study period ranged between 11.21 to 12.14% while it ranged between 17.96 to 18.45% on Obantoko 11 kV feeder. These values were found to exceed the permissible 10% limit of the operating voltage. The highest voltage drop of 12.14 and 18.45%, respectively observed on FUNAAB 33 kV and Obantoko 11 kV feeders occurred in the year 2022. Further observations revealed that 68% of the 20.26 km length of Obantoko 11 kV feeder involved the use of under-rated 70 mm2aluminium conductor (AlC), leading to high power loss and voltage drop unlike FUNAAB 33 kV feeder where 63% of the 57.4 km length of the line was constructed with the standard 150 mm2AlC. Analysis of commercial and collection losses on both feeders revealed a remarkable energy accountability challenges throughout the study period, a continual gap in energy received and billed was evident.The highest commercial loss of ₦3,683,071 on FUNAAB 33 kV feeder occurred in the year 2022 while the collection loss was highest in the year 2020 at a worth of ₦328,752,293. Similarly, the highest commercial loss of ₦4,202,467experienced on Obantoko 11 kV feeder occurred in the year 2023 while the highest collection loss of ₦149,056,487 was experienced in the year 2021.These results were indication that feeder characteristics, billing and consumer enumeration systems were key factors that appreciably influenced ATC&C losseson the case feeders. The aggregate technical, commercial and collection losses analysed in the study revealed the operational inefficiencies of the considered electricity distribution network feeders.