Browsing by Author "Ibrahim, Khalifa Aliyu"
Now showing 1 - 5 of 5
Results Per Page
Sort Options
Item Open Access Advancing hydrogen: a closer look at implementation factors, current status and future potential(MDPI, 2023-12-08) Kaheel, Sultan; Ibrahim, Khalifa Aliyu; Fallatah, Gasem; Lakshminarayanan, Venkatasubramanian; Luk, Patrick; Luo, ZhenhuaThis review article provides a comprehensive analysis of the hydrogen landscape, outlining the imperative for enhanced hydrogen production, implementation, and utilisation. It places the question of how to accelerate hydrogen adoption within the broader context of sustainable energy transitions and international commitments to reduce carbon emissions. It discusses influencing factors and policies for best practices in hydrogen energy application. Through an in-depth exploration of key factors affecting hydrogen implementation, this study provides insights into the complex interplay of both technical and logistical factors. It also discusses the challenges of planning, constructing infrastructure, and overcoming geographical constraints in the transition to hydrogen-based energy systems. The drive to achieve net-zero carbon emissions is contingent on accelerating clean hydrogen development, with blue and green hydrogen poised to complement traditional fuels. Public–private partnerships are emerging as catalysts for the commercialisation of hydrogen and fuel-cell technologies, fostering hydrogen demonstration projects worldwide. The anticipated integration of clean hydrogen into various sectors in the coming years signifies its importance as a complementary energy source, although specific applications across industries remain undefined. The paper provides a good reference on the gradual integration of hydrogen into the energy landscape, marking a significant step forward toward a cleaner, greener future.Item Open Access Cooling of concentrated photovoltaic cells - a review and the perspective of pulsating flow cooling(MDPI, 2023-03-18) Ibrahim, Khalifa Aliyu; Luk, Patrick Chi-Kwong; Luo, ZhenhuaThis article presents a review to provide up-to-date research findings on concentrated photovoltaic (CPV) cooling, explore the key challenges and opportunities, and discuss the limitations. In addition, it provides a vision of a possible future trend and a glimpse of a promising novel approach to CPV cooling based on pulsating flow, in contrast to existing cooling methods. Non-concentrated photovoltaics (PV) have modest efficiency of up to around 20% because they utilise only a narrow spectrum of solar irradiation for electricity conversion. Therefore, recent advances employed multi-junction PV or CPV to widen the irradiation spectrum for conversion. CPV systems concentrate solar irradiation on the cell’s surface, producing high solar flux and temperature. The efficient cooling of CPV cells is critical to avoid thermal degradation and ensure optimal performance. Studies have shown that pulsating flow can enhance heat transfer in various engineering applications. The advantage of pulsating flow over steady flow is that it can create additional turbulence and mixing in the fluid, resulting in a higher heat transfer coefficient. Simulation results with experimental validation demonstrate the enhancement of this new cooling approach for future CPV systems. The use of pulsating flow in CPV cooling has shown promising results in improving heat transfer and reducing temperature gradients.Item Open Access Design and performance analysis of concentrated photovoltaic cooling.(Cranfield University, 2023-01) Ibrahim, Khalifa Aliyu; Luk, Patrick Chi-Kwong; Kahagala Gamage, UpulThe use of solar energy as a global energy source has increased over the past two decades. Photovoltaic cells, which utilise the sun to generate electricity, are a promising alternative to fossil fuels that contribute to climate change. However, the high intensity of concentrated solar radiation can cause overheating in photovoltaic cells, reducing their efficiency and power output. Researchers worldwide are improving cooling in concentrated photovoltaic cells (CPV) to enhance temperature uniformity and improve power output. Previous studies have demonstrated that pulsating flow can effectively enhance heat transfer in various fields, including electronics, mechanical engineering, and medicine. In this research, three flow patterns (continuous flow, uniform pulsating flow, and bio-inspired pulsating flow) were studied in both simulation and experimental designs. Two cooling designs were considered: the conventional design (C- Design) and the parallel design with baffles (W-B) and without baffles (Wout-B). With the implementation of 30 pulses per minute bio-inspired pulsating flow a reduction of 1.96% in solar cell temperature was observed when compared to continuous flow. This reduction in temperature was consistently observed across a range of flow rates from 0.5 to 2.5 L/m, employing the parallel Wout-B design. Notably, the bio-inspired pulsating flow shows better performance in comparison to uniform pulsating flow, as well as the conventional designs with continuous flow and uniform pulsating flow, resulting in notable improvements in cooling efficiency of 1.22%, 2.14%, and 4.00%, respectively. In terms of a direct comparison, the implementation of uniform pulsating flow in the parallel Wout-B design exhibited a maximum cooling improvement of 0.74% when contrasted with continuous flow. Furthermore, when assessing uniform pulsating flow against the C-design with uniform pulsating flow in the parallel Wout-B design, a noteworthy enhancement of 0.93% was observed. Remarkably, the C-design with uniform pulsating flow demonstrated a superior effectiveness of 1.90% when compared to the C-design with continuous flow.Item Open Access Harnessing energy for wearables: a review of radio frequency energy harvesting technologies(MDPI, 2023-07-31) Nwalike, Ezekiel Darlington; Ibrahim, Khalifa Aliyu; Crawley, Fergus; Qin, Qing; Luk, Patrick; Luo, ZhenhuaWireless energy harvesting enables the conversion of ambient energy into electrical power for small wireless electronic devices. This technology offers numerous advantages, including availability, ease of implementation, wireless functionality, and cost-effectiveness. Radio frequency energy harvesting (RFEH) is a specific type of wireless energy harvesting that enables wireless power transfer by utilizing RF signals. RFEH holds immense potential for extending the lifespan of wireless sensors and wearable electronics that require low-power operation. However, despite significant advancements in RFEH technology for self-sustainable wearable devices, numerous challenges persist. This literature review focuses on three key areas: materials, antenna design, and power management, to delve into the research challenges of RFEH comprehensively. By providing an up-to-date review of research findings on RFEH, this review aims to shed light on the critical challenges, potential opportunities, and existing limitations. Moreover, it emphasizes the importance of further research and development in RFEH to advance its state-of-the-art and offer a vision for future trends in this technology.Item Open Access A scalable optical meta-surface glazing design for agricultural greenhouses(IOP Publishing, 2024-02-16) Lakshminarayanan, Venkatasubramanian; Ranjbar, Mostafa; Ibrahim, Khalifa Aliyu; Luo, ZhenhuaOptical meta-surfaces allow controllable reflection and transmission spectra in both optical and infrared regions. In this study, we explore their potential in enhancing the performance of low-emission glazing designed for improved energy efficiency, for agricultural greenhouses in cold climates. The low-emission glazing employs thin film optics to retain heat by allowing solar radiation while reflecting radiation emitted by room-temperature objects. The incorporation of metamaterials that can be scalably manufactured and designed for capturing solar energy in the mid-infrared spectrum, offers an opportunity to further enhance the glazing's energy efficiency. Based on existing literature, the finite difference time domain (FDTD) method and the transfer matrix method are utilised to propose a metamaterial structure, with spherical silver nanoparticles and thin-films. We compare the performance of this proposed design against existing materials. The outcome of this study offers insights into the potential of metamaterials in optimizing the energy efficiency of cold-climate agricultural greenhouses.