• Energy Research

The increasing demand and cost of conventional fuels have forced humanity to consider various alternative fuels. Low yield and massive cost are significant limitations in biofuel production. Nanotechnology has emerged as a prominent research area in the scientific community with a wide range of applications, including biofuels. This review discusses the specific approaches and methods to synthesize nanoparticles from natural materials. In addition, it summarizes the use of nanocatalyst, nano-additives and microbial enzymes to enhance biofuel properties and production processes. This review also highlights the effect of plant-based nanoparticles on diesel engines' combustion performance and emissions.

To address the increasing energy demand, replacing conventional energy systems with non-conventional resources like solar power generation is crucial. Photovoltaic (PV) panels play a significant role in harnessing solar energy and converting it into electrical power. However, the solar cells’ temperature dramatically influences the panel’s performance, particularly in hot climates. In this study, a detailed mathematical model is developed and conducted simulations using three different phase change materials (PCMs)—RT21, RT35, and RT44—integrated with PV panels in various climate conditions worldwide during the summer season. An optimization model is also created using MATLAB and a genetic algorithm to identify the most suitable PCM for specific climate zones. The findings revealed that incorporating PCM resulted in a surface temperature reduction of PV panels, leading to a 6% increase in efficiency and a 16% boost in electrical output. Specifically, when using a PCM with a melting point of 21°C, the maximum cell temperature during summer operation decreased from 65°C to 38°C. Similar temperature reductions were observed when using PCMs with melting points of 35°C and 44°C. Current analysis demonstrates that the correct selection of a phase change material can decrease panel temperature by approximately 39% in June. Furthermore, PCM with a melting point of 21°C exhibited the best outcomes in terms of maximum electrical performance, efficiency, and PV cell temperature reduction.

The need for effective and sustainable thermal management systems is expanding across a variety of industries, and phase change materials (PCMs) have become a flexible alternative to meet this demand. The ability of phase change materials to store significant amounts of heat during their phase transition over a constrained temperature range make them attractive candidates for temperature regulation or energy storage applications in several industrial sectors. This review paper examines recent developments in PCM applications and their significant effects on a range of industries, including building and construction, solar energy storage, electronics, automobiles, pharma and health care, waste heat recovery, electricity generation, water treatment, food and beverages, and textiles. The article starts off by giving a basic overview of PCMs and explaining their distinctive thermal properties, classification, and operating principles. It then delves into the in-depth study, covering the recent advancements of PCM applications. This extensive assessment covers both prospective directions for further study and development as well as the crucial elements influencing the practical application of PCMs. Overall, this article provides a thorough summary of the developments in PCM applications across a range of industries, emphasizing their enormous potential to improve energy efficiency, lower carbon emissions, and promote sustainable development. It is a useful resource for scientists, engineers, and decision-makers working in the domains of thermal engineering, energy management, and materials science. It encourages greater PCM innovation and application for a more sustainable and efficient world.

Electric vehicles (EV) are a relatively contemporary and emerging technology in the transportation and power sectors, with several economic and environmental advantages. However, there are still challenges associated with EV charging depending on on-grid electricity. University buildings that consume a lot of energy continue to rely on the grid and/or conventional fuel for consumption. In addition, EV Charging will create more challenges in meeting the demand; therefore, utilizing university rooftops for EV charging has high prospects of meeting the additional energy demand. In Malaysia, no such research has been presented that has explored the possibility of using academic institute rooftops for BIPV installation for EV Charging in terms of energy and environmental standpoint. The current study analyzes and evaluates a rooftop grid-connected Building Integrated photovoltaic (BIPV) system for generating electricity and EV charging at the University Malaysia Pahang, Malaysia, for EV charging. The system’s energy output has been simulated using the PVSyst in two scenarios, i.e., fully integrated with no ventilation and free mounted with air circulation. It was found that 7000 m2 of the selected building’s rooftop area could be used for panel installation. The panels’ total capacity was 1.069 MW, with total annual electricity production of 1587 MWh and 1669 MWh in respective scenarios. The proposed BIPV plant would reduce GHG emissions of 60,031 tons of CO2e in scenarios 1 and 61,191 tons of CO2 in scenario 2 compared to the emission produced by coal plants for the same amount of annual energy generation.

Abstract Sunlight is often deemed as the only abundant and truly “free” energy resource. Among all the different techniques available to harness solar energy, the most popular and mature technology is the photovoltaic conversion of sunlight into electricity. Despite its merits, solar PV technology has issues with the land requirement (especially in urban areas), capture efficiency and public perception (due to the absence of pleasing aesthetics). The concept of a solar tree is capable of addressing these problems effectively with elegance. In this paper an attempt is made to review the components of the solar tree and its design. The various commercial designs are also discussed along with applications of the solar tree. The paper also addresses the challenges involved with this technology and suggests future research direction.

With its unique qualities, such as infinite supply, high octane number, and capacity to cut greenhouse gas emissions, alcohol is a viable alternative fuel for SI engines. This review article aims to reveal to readers the effects of alcohol on the performance, combustion behavior, and emission characteristics of SI engines by collecting the outcomes from previous research. This article looks at methanol, ethanol, and butanol fuel qualities. The performance of SI engines with butanol, ethanol, and methanol combined with gasoline is investigated in terms of brake torque, brake power, fuel consumption, thermal efficiency, volumetric efficiency, mean effective pressure, and coefficient of variation under various conditions. Second, in-cylinder pressure, mass fraction burnt, ignition delay, pressure increases, and heat release rates are also used to evaluate the combustion characteristic. Finally, the article discusses pollutant emissions such as CO, CO2, NOx, UHC, and exhaust gas temperature. Methanol, ethanol, and butanol mixed with gasoline increased fuel consumption and lowered spark-ignition engines’ thermal efficiency. When alcohol was combined with gasoline, most research found that CO, NOx, and UHC emissions were reduced due to improved combustion.

Environmental, economic and political pressures have driven the interest towards the search of sustainable feedstock for biofuel production. At present, macroalgae (green, brown and red marine seaweed) is getting growing consideration as an alternative resource for sustainable biomass to produce biofuels, biochemical and food. The unique chemical composition and wide variation in the availability create various opportunities and also challenges for bio-based energy production. Recently, numerous studies have taken place in the exploitation of seaweed as carbon sources for the bioethanol production. Thus, this paper attempts to highlight the characteristics, processing techniques and potential applications of the seaweed. The present review also focuses on recent innovative approaches for the sustainable production of bioenergy from seaweed.

Solar energy provides desired thermal energy for diverse applications, including industrial heating, domestic cooking, power generation, desalination, and agri-food preservation. Despite extensive research on solar drying from the scientific community, there are limited practical applications for small-scale use. This review attempts to analyze the design features of three specific types of dryers for food drying applications: solar evacuated tube dryers, biomass dryers, and hybrid solar dryers. The thermal performance of the three dryers is evaluated in terms of drying time, moisture removal, and temperature attained during drying. The review also assesses the prospects of solar dryers, highlighting the need for further research into innovative designs and advanced drying capabilities. The study provides valuable information for enhancing dryer performance with various integrated solutions.

The efficiency of photovoltaic (PV) panels is significantly affected by environmental factors such as solar irradiance, wind speed, humidity, dust accumulation, shading, and surface temperature, with thermal buildup being the primary cause of efficiency degradation. In this review, we examined various cooling techniques to mitigate heat accumulation and enhance PV panel performance. A comprehensive analysis of active, passive, and hybrid cooling strategies is presented, including heat pipe-based cooling, heat sinks, holographic films, nanofluids, phase change materials (PCM), thermoelectric, biomaterial-based, and hybrid cooling systems. The effectiveness of these techniques in reducing surface temperature and improving electrical efficiency was assessed. Notably, heat pipe cooling and hybrid PCM-thermoelectric systems demonstrated the most promising improvements, with some methods achieving temperature reductions exceeding 40 ℃ and efficiency enhancements over 15%. Future research directions include developing advanced nanofluid formulations, optimizing the design of heat pipes and heat sinks, integrating multi-functional coatings, and enhancing the real-world durability of cooling materials for inventing innovative, sustainable, and eco-friendly cooling systems. By providing a structured assessment of emerging PV cooling techniques, this study is a valuable resource for researchers and engineers striving to improve solar energy efficiency, reduce thermal losses, and advance the sustainability of photovoltaic technologies.