Ovis Daniel Irefu

Dr. Ovis Daniel Irefu

orcid

Research Focus & Metrics

Academic Career Length

3Years (2024-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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3 April 2024 in Journal of Energy and Power Technology
Verified
Journal Article
Open access
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JZJesse Tanko Zarmai
Jesse Tanko Zarmai
IAIsaac Ibitoye Alabi
Isaac Ibitoye Alabi
EEEbimene Ezekiel Ebisine
Ebimene Ezekiel Ebisine
MZMusa Tanko Zarmai
Musa Tanko Zarmai
Ovis Daniel IrefuOvis Daniel Irefu
Ovis Daniel Irefu
Inadequate electricity supply is a global challenge that needs solutions. This situation has compelled the purchasing of fossil fuel-generating units for use in residential, commercial, and industrial sectors to generate electricity. However, using fossil fuel generating units cause greenhouse gas emissions, bringing about environmental pollution and ultimately resulting in climate change. In particular, educational institutions require adequate and reliable power supply to ensure proper learning and teaching, which is lacking in developing countries like Nigeria. Fortunately, Nigeria has enormous renewable energy sources such as solar energy, which can be utilized through photovoltaic (PV) modules to generate clean energy fed into a mini-grid. This novel approach focused on an educational institution that will enable adequate electricity from the mini-grid for proper learning and teaching, reduced negative environmental impacts, and lower energy costs. Therefore, this research is focused on developing an effective hybrid utility grid-diesel generator-solar PV mini-grid system for the Faculty of Engineering and Technology of the Nigerian Defence Academy, Kaduna. Design analysis and techno-economic evaluation of the mini-grid were carried out using the HOMER Pro software tool, which was also used to simulate and optimize the mini-grid. The results revealed that the hybrid system comprising the grid, diesel generator, PV, and converter was technically and economically viable. The net present cost (NPC) of $182,065.20, producing a total energy of 836,430 kWh/year, was obtained and gave 0.00198 $/kWh as a levelized cost of energy (LCOE). Correspondingly, a renewable fraction (RF) of 98.3% was attained, thus meeting the Faculty's daily load demand of 575.64 kWh/day, thereby providing a reliable and improved energy supply at the best cost. Therefore, a hybrid system such as this one is proposed for tertiary institutions to ensure greater electric power supply availability.

1 March 2024 in International Journal of Power Electronics and Drive Systems (IJPEDS)
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Journal Article
Open access
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OTOmokhafe James Tola
Omokhafe James Tola
Ovis Daniel IrefuOvis Daniel Irefu
Ovis Daniel Irefu
James Garba AmbafiJames Garba Ambafi
James Garba Ambafi
This paper presents a modified fractional-order proportional-integral-differential (MFOPID) controller for load frequency control in an Island microgrid based on an electric vehicle (EV) and renewable energy source. It tackles the intermittent energy sources and the dynamic of the load change with reduced speed and the quality of response generated on the microgrid. The MFOPID controller gains are well turned using a metaheuristic grasshopper optimization algorithm (GOA) technique to determine its robustness and optimal system performance. The controller gains are evaluated with three different searching agent populations. The proposed MFOPID with GOA improved system performance frequency by 19.485 Hz compared to 14.1151 Hz of the benchmark model. It takes 6.9068 s of the proposed model to settle compared to 16.6796 s of FOPID.

6 March 2024
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Book Chapter
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EEEmmanuel Epelle
Emmanuel Epelle
WOWinifred Obande
Winifred Obande
Ovis Daniel IrefuOvis Daniel Irefu
Ovis Daniel Irefu
AMAlivia Mukherjee
Alivia Mukherjee
Thermochemical processes utilize heat and chemical reactions for the release of hydrogen (H2) from organic materials, including fossil fuels and biomass. In some thermochemical processes, the combination of heat with closed-chemical cycles generates H2 from feedstock such as lignocellulosic biomass, plastics, and aquatic plants. Some of the major challenges facing renewable H2 production include the high-temperature requirements for biomass decomposition and water splitting as well as the correspondingly expensive thermal-resistant materials needed for these processes. An overview of the role of nanomaterials in mitigating these challenges is presented in this chapter, with emphasis placed on thermochemical water splitting, given its considerable promise. Generally, the application of nanomaterials (as catalysts) improves the overall thermochemical process efficiency. The specific improvement routes include a reduction of the high-temperature requirements, reduced tar formation, improved reactant conversion, and an increase in the H2 yield and stability over several cycles. This chapter further discusses some of the recent advancements in renewable nanomaterial-based thermochemical water splitting and highlights crucial challenges to be addressed for the large-scale uptake and commercial implementation of this H2 production route. <!----> <!----> <!----> <!---->

1 June 2024 in International Journal of Power Electronics and Drive Systems (IJPEDS)
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Journal Article
Open access
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GEGodslove Isenyo Ebiega
Godslove Isenyo Ebiega
TDTerdoo M. Dugeri
Terdoo M. Dugeri
Ovis Daniel IrefuOvis Daniel Irefu
Ovis Daniel Irefu
The energy crisis in Nigeria has continued to impede the rapid expansion of the telecommunication industry, whose operating expenditure is galloping due to over-dependence on diesel generators as an alternative source of power to its base transceiver station (BTS). This fossil-fuel power source has also increased the industry’s carbon footprint. As a solution to these problems, the objective of this work is to provide a sustainable and quality hybrid DC power supply system for BTS that would increase access to information and communication technology or ICT infrastructure. This involves the integration of solar & wind energy with the grid. The sizing of the hybrid sub-systems was designed & simulated using MATLAB Simulink to test for functionality. A prototype of the design system was then implemented with the results showing an average power output that guarantees 21 hours/day of supply. By installing this hybrid system of 1.3 kW, approximately 2.55 kg of diesel (C10H20) would be un-utilized by one BTS, thereby preventing 3.6 kg of CO2 from been emitted to the atmosphere daily. Extrapolating these values shows 930.75 kg of diesel can be saved and reduce 1314 kg of CO2 emission within a year. Hence eliminating the need for diesel-backup generator for a grid connected or non-grid BTS sited in rural areas.

29 October 2026 in Preprints.org
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Ovis Daniel IrefuOvis Daniel Irefu
Ovis Daniel Irefu
GEGodslove Isenyo Ebiega
Godslove Isenyo Ebiega
BSBreana Smithers
Breana Smithers
MAMiguel F. Acevedo
Miguel F. Acevedo
Field evidence for hybrid renewable microgrids remains scarce, and reliability indices measured on operating systems are rarely qualified by their operating conditions. This paper reports on the design and field evaluation of a 24 V direct-current microgrid that combines photovoltaic (PV) and wind generation with lead-acid storage and a parabolic-dish thermoelectric branch on a shared bus. Reliability was assessed from metered field campaigns (696,595 records) and a design-basis suite using Loss of Power Supply Probability (LPSP), Loss of Load Expectation (LOLE), and two storage-independent indices. At the metered load, wind reduced battery-supplied energy by 17.9% (13.5% at night) and generation adequacy LPSP from 47.9% to 39.4% by generating at night and under low irradiance. Under a 140 W design-basis load, wind reduced LPSP from 4.18% to 0.93%, but the same load over a different resource window (calendar period of measured weather) yielded 24.1%, showing that reliability indices depend jointly on load, storage, and resource window. For the thermoelectric branch, diagnostic elimination showed that manual-tracking dwell time and optical-interface coupling govern output; repositioning the modules raised delivered power from 13.11 W to 50.96 W.

26 August 2026 in Journal of Energy and Power Technology
Verified
Journal Article
Open access
PDF file
Ovis Daniel IrefuOvis Daniel Irefu
Ovis Daniel Irefu
GEGodslove Isenyo Ebiega
Godslove Isenyo Ebiega
TDTerdoo M. Dugeri
Terdoo M. Dugeri
SFSeyi J. Fanifosi
Seyi J. Fanifosi
Renewable energy systems play a critical role in reducing carbon emissions and promoting energy sustainability. Conventional battery storage remains the dominant but problematic solution for intermittency management in off-grid renewable energy systems (RES), imposing high capital costs ($150-400/kWh for lithium-ion), short replacement cycles of 3-15 years, and significant environmental burdens from toxic material disposal barriers that are particularly acute in the remote and resource-limited communities that most need reliable clean energy. This paper presents a systematic review of battery-less off-grid RES, synthesizing evidence across six alternative energy storage and dispatch technologies: supercapacitors, mechanical flywheels, compressed air energy storage (CAES), pumped hydroelectric storage (PHS), hydrogen storage via PEM electrolysis, and molten salt thermal energy storage (TES). The review spans single-source, dual-source, and multi-source configurations, with documented applications in seawater reverse osmosis desalination, agricultural water pumping, rural electrification, and small-scale industrial processes. A comparative performance analysis reveals that no single battery-less technology is universally optimal; rather, hybrid approaches particularly molten salt TES paired with hydrogen storage offer the most robust solution for continuous, dispatchable off-grid power. Building on this synthesis, the paper proposes and characterizes a novel integrated battery-less microgrid combining solar photovoltaic (PV), wind turbine (WT), and concentrated solar power (CSP) with molten salt thermal storage and PEM-based green hydrogen production. The system’s defining innovation is the dual-pathway utilization of stored hydrogen: as a long-duration electricity backup via fuel cells and as a direct fuel for agricultural vehicles and equipment, eliminating diesel dependence in off-grid farming contexts. Key findings indicate that such integrated systems can reduce curtailed renewable energy by up to 79%, eliminate battery replacement costs over a 20-year operational lifespan, and provide multi-day energy autonomy without chemical battery storage. Critical challenges including electrolyzer cost reduction, small-scale CSP adaptation, and energy management system design are identified as priority directions for future research to enable widespread deployment. HOMER Pro-based techno-economic validation is identified as the immediate next step in this research work.