Integration of magnetic residuals,derivates and located euler deconvolution for structural and geologic mapping of parts of the precambrian gneisses of Ago-Iwoye, Southwestern Nigeria

Ground based magnetic survey conducted between longitude 06O 55I 51IIN –06O 55I 54IIN and latitude 03O 52I 06IIE –03O 52I 4.8IIE (Olabisi Onabanjo University) remarkably revealed a consistent subsurface NW -SE structural azimuth of localized discontinuities within the shallowly buried heterogeneous basement rocks, which at exposed locations are composed of strongly foliated granite gneiss and migmatite-gneiss with veins and veinlets principally orientated in NNW –SSE direction.Magnetic survey of the area was preceded by site inspection to avoid metallic objects interferences. Field procedure in the area involved Cartesian gridding, base station establishment, data acquisition at gridded points, and repeated bihourly diurnal checksat the base station. At the processing stage, diurnal variation effect was aptly removed before subjection to Kriging (gridding). The gridded data was then prepared as input for Forward Fourier Filter Transform (FFT), which upon definition and implementation enabled Butterworth filtering of isolated ringing effects, reduction to the equator (RTE) for geomagnetic correction, and the use of Gaussian and Upward Continuation filtering for regional magnetic intensity trend determination. Removal of the regional magnetic intensity (RMI) from the total magnetic intensity (TMI) resulted in the derivation of the residual anomaly. Enhancement filters adopted for better resolution of the residual magnetic gradient include analytical signal (AS), tilt-angle derivative (TDR), vertical derivative deconvolution (VDD), and the first vertical derivatives (FVD).TMI and RMI values range between 32925nT –33050nT and 32935nT –333050nT respectively, while the residual gradient ranges between 15nT/m and10nT/m; AS ranges between 0.28nT/m and4.1nT/m; and TDR ranges from-1.4nT/m to 1.4nT/m. Source depth calculation estimated from power spectrum analysis and Euler deconvolution ranges between 1m and15m. Composite overlay of magnetic maps revealed jointed and faulted zones within the area; exhibiting a NW-SE principal azimuth of Liberian orogenic impress, which are in consistence with the foliation direction of the jagged foliated bedrock with an estimated maximum overburden of about 15m.The structural significance of this area as a prospective hydro-geological centre, and as an undesirable spot for high-rise building has been accurately evaluated from research findings. Application of integrated geophysical approach, complemented by detailed geological studies may furnish greater information about the subsurface structural architecture.Keywords:Gneisses; Ground Magnetic Surveying;RTE;Structural discontinuities;TDR.1INTRODUCTIONStructuralmapping is an integral part of geologic surveys. It involves measurements, analyses, interpretation and recognition of geometrical features (structures) generated by rock deformations [1]. These structures often serve as fountains of environmental challenges or unparalleled opportunities depending on their modesof occurrences, which in most cases are imminently controlled by the dynamic interplay of differential stress distributions within the earth interior. In line with the principle of uniformitarianism, a broad understanding about Earth’s paleo processes and internal workingsare deductible from the various deformation types for diverse applications. Deductible inferences from brittle deformationsinclude the kinematics of crustal blocks, orientation of principal axes of regional and local stresses, and geometry. Deeper insights indeep seated stresses, regional movements and block motions are obtainable from ductile deformations

Aeromagnetic Interpretation of Basement Structures and Geometry in Parts of the Middle Benue Trough, North Central, Nigeria

The research of an analysis of aeromagnetic data collected in the middle Benue Trough in north-central Nigeria is presented. A detailed analysis of basement structures is conducted in order to identify regions with high hydrocarbon potential that is different from those discovered by earlier researchers. Aeromagnetic data were filtered by using the Butterworth and Gaussian filters, transformed by engaging the reduction to the equator technique, and subsequently enhanced. To estimate magnetic basement depths at various places throughout the basin, the Euler deconvolution depth weighting approach was used. Eleven (11) sub-basins with depths ranging from –2000 m to –8000 m were also identified by Euler’s findings. The sub-basins trend in the NE-SW direction while the average sediment thickness is found to be more than 3 km. The extracted structural features indicate areas like Kadi Blam and Kado areas in the southeastern part and Ogoja and Obudu in the southern part of the study area as regions with high structural densities. These areas coincide with the areas delineated as the sub-basins. The cross-sections generated reveal depressions caused by the action of some tectonic activities in the area. This study identified undulating basement topography believed to be due to tectonic activities as well as five areas that are possible targets for hydrocarbon exploration

Multicriteria-based methodology for the design of rural electrification systems. A case study in Nigeria

Electrification with micro-grids is receiving increasing attention to electrify rural areas in developing countries. However, determining the best local supply solution is a complex problem that requires considering different generation technologies (i.e. solar PV, wind or diesel) and different system configurations (off-grid or on-grid). Most existing decision aid tools to assess this design only consider economical and technical issues in a single optimization process. However, social and environmental considerations have been proven key issues to ensure long-term sustainability of the projects. In this context, the objective of this work is to develop a multicriteria procedure to allow comparing electrification designs with on-grid or isolated micro-grids and different tech-nologies considering multiple aspects. This multicriteria procedure is integrated in a two-phased methodology to assist the design of the system to electrification promoters in a structured process. First, different electrification alternatives are generated with an open-source techno-economic optimization model; next, these alternatives are evaluated and ranked with the multicriteria procedure, which considers 12 criteria representing economic, technical, socio-institutional and environmental aspects. The whole design methodology is validated with a real case study of 26 population settlements in Plateau State, Nigeria. Experts in rural electrification within the Nigerian context have been consulted to weight the criteria and particularize their evaluation for the specific case study. Results show that solar PV technology based systems are the most suitable electrification designs for communities in Nigeria, while grid connection feasibility depends on the size of the community and the distance to the closest national grid consumption point.Peer ReviewedPostprint (author's final draft

Analysis of energy revenue and electrical power losses in distribution line

This study presents the analysis of energy revenue and electrical power losses in distribution network, aimed to determine the energy losses on power distribution system. The 11kV power transmission line at Ujokuen community feeding to Benson Idahosa University was investigated. The following data were obtained as follow: energy delivered, energy billing, total cash amount, billed collected and correspond percentage. From the research work various technical power losses associated with power distribution network were determined and their effect on energy delivered and energy billing and corresponding difference under the area of investigation. It was observed that energy delivered is not constant or linear for the year 2013. The comparison of energy delivered and energy billed for various years were determined. It was observed that there is decreased in energy delivered and energy billed from 2013 to 2015 and the system witnessed a slightly increase of energy delivered and energy billed from 2016 to 2018. The energy level differentials are due to copper losses, energy theft and core loss

Integrated design of photovoltaic power generation plant with pumped hydro storage system and agricultural facilities in Uhuelem-Amoncha African community

Seasonal and location dependence of renewable energy resources have limited their applications in power generation. Energy storage systems are promising solutions to the intermittence of renewable energy resources. Rural electricity grids are faced with economic sustainability challenges due to low power demand and poverty. As countries hopefully pass through various stages of development, their needs change. The electricity needs of developing countries surely differ from those of developed economies. Most of the global population without access to electricity, and all the consequences of it, is found in developing countries. Energy access is undoubtedly a significant catalyst for development. Developed countries mainly require technologies to ensure energy security, resilience, and occasionally emission control. Therefore, microgrids are emerging technologies capable of supporting the diverse needs of various stages of development. For example, a rural grid design around economic drivers like agriculture and micro industries can mitigate poverty and improve economic sustainability of rural grids. This study presents an Integrated Design of Photovoltaic Power Generation Plant with Pumped Hydro Storage System and Agricultural Facilities in Uhuelem-Amoncha African Community. The design explored the natural availability of water body in an elevated settlement area that offers a natural storage height for hydro energy storage. HOMER (Hybrid Optimization of Multiple Energy Resources) software was deployed to optimize the design. The designed photovoltaic power generation plant has a nominal capacity of 221 kW. The simulated results show the power supply probability of the plant as 99.9%. The cost of energy (COE) offered by the design is 0.456 [US$/kWh] which is 82% lower than the current cost of energy in the project community based on generation through petrol generators. The System has 100% renewable energy penetration. The plant is designed to power 50 households with a daily domestic energy consumption of 4.46 [kWh] each. The plant capacity also covers the irrigation water requirement of 50 acres of corn farms. A total of 100 units of designed intelligent pest control system will also be powered by the plant. A community refrigeration scheme of 27 [m3] equivalent volume is part of the plant design load. The benefits from the irrigation, water supply, pest control and refrigeration scheme will enhance the community’s socio-economic development and sustain the investment. Quantifying the integral socio-economic and environmental benefits is a subject of a future research

Depth to magnetic sources determination using Source Parameter Imaging (SPI) of aeromagnetic data of parts of Central and North-Eastern Nigeria: a reconnaissance tool for geothermal exploration in the area

Source Parameter Imaging (SPI) of aeromagnetic data covering an area located approximately between latitude 7.5o N and 11.5o N and longitude 7.5o E and 10.5o E, which corresponds to parts of the Benue trough (lower part of the Upper Benue trough, the entire middle Benue trough, and upper part of the Lower Benue trough), lower part of the Gongola and Yola Basins, the Precambrian Basement, the Jurassic Younger Granites and two prominent hot Springs, Wiki hot spring in Bauchi state (in the north-eastern part) and Akiri hot spring in Nasarawa state (in the south-western part) of central and north-eastern Nigeria, was carried out for the purpose of estimating the depth to magnetic basement of the area. The estimated depths to magnetic sources from Source parameter imaging (SPI), range from 0.12 to 12.26 km. The highest depth can be found at the south-western part of the study area. The depth to magnetic basement is shallower mainly in the north and extreme north-eastern parts of the study area with magnetic high flanking areas of magnetic low. The above characteristics of these areas and the location of warm springs at the north-eastern and south-western parts of the study area (Wikki and Akiri hot springs respectively). Which suggests the occurrence of tectonic activities in the area, hence is an indication that, there might probably be good sources for geothermal and thereby recommended for both geothermal exploration and exploitation

ANALYSIS OF THE TRANSIENT STABILITY LIMIT OF NIGERIA’S 330kV TRANSMISSION SUB-NETWORK

The poor investment in the network expansion programme has led to high level of grid fragility experienced in the power transmission system in Nigeria. Thus, any little disturbance often results in cascaded outage which is very hazardous to the power system equipment and operation. In order to overcome or ameliorate the influence of this challenge, the network engineers have to devise methodologies based on the dynamic stability analysis. This motivates the development of power system transient stability model presented herein. The developed model is thus applied to a specimen of the Nigeria’s transmission power system, i.e. the Ikeja-West Sub-network. This choice is influenced by the fact that the Ikeja-West sub-network is the hub of power transmission arteries in Nigeria. Thus the Electrical Transient and Analysis Program (ETAP) software is deployed to operate on the ensuing model. This then leads to generating a series of results that demonstrates the different scenarios in respect of the system stability studies. The method adopted is quite appealing and promising as a tool in sustaining system stability and security during slight disturbance to the network during operation.http://dx.doi.org/10.4314/njt.v36i1.2

Performance evaluation of 2.4kVA grid-tie inverter

This paper is focused on experimenting the overall performance of a 2.4kVA direct solar power supply system. The overall aim is to implement a solar power supply system without a battery back-up in order to minimize cost. The objectives include measuring the performance of grid-tie inverter, determine its period of operation under load conditions, to make the use of batteries optional in solar power supply system and minimize initial cost of installation. Various tests (variable load, fixed load and no-load) were carried out for the purpose of analysis. A dual trace digital storage oscilloscope was used to monitor the output waveform of the inverter to observe possible harmonic distortion on the waveform. The inverter takes its input power directly from the solar modules (panels) through the maximum power point tracker (MPPT) charge controller. Each category of test was conducted for at least three days of different weather conditions, to determine how variation in the sun’s intensity (irradiance) affects the operation of the inverter and its output power. Test results show that the inverter performs its function during the day apart from the early hours in the morning and later in the evening of each day, and the loads were powered successfully during the period of test.  The output waveform as observed from the oscilloscope is not purely sinusoidal; it is rather a modified sine wave

Towards achieving energy for sustainable development in Nigeria

The importance of energy availability in the economic growth, social and political development of every nation cannot be overemphasized. Affordable and reliable energy availability is the precondition for sustainable development. Sustainable development calls for an efficient, reliable and decentralized energy economy, based on local and clean energy sources, in which the price paid by the consumer will reflect the real cost of energy products to the economy. There is clear evidence that Nigeria is blessed with abundant resources of fossil fuels as well as renewable energy resources. The major challenge is inefficient utilization of energy in the country. There is no doubt that the present power crisis afflicting Nigeria will persist unless the government diversifies her energy sources and adopt new available technologies to reduce energy wastages and save cost. This study examines the perspective of energy efficiency and renewable energy in the making of strategies for a sustainable development in Nigeria. Such strategies involve energy savings on the demand side, efficiency improvements in the energy production, and replacement of fossil fuels by various sources of renewable energy. Factors that need to be considered in the shift to its sustainable energy future are examined in this article