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Topic Review
Renewable Energy Sources
Renewable energy sources (RES) have many advantages: (a) increase in RES consumption provides reliability on energy supply and reduces dependence on energy import; (b) larger use of RES is an important measure for the reduction of energy-related greenhouse gas (GHG) emissions; and (c) deployment of RES creates additional employment, stimulates regional economic development, and contributes to the implementation of modern technologies. Various aspects of RES deployment have been analysed in the relevant literature. Currently, the most important aspects are: (a) the role of RES consumption on economic growth; (b) the effect of RES deployment on the decline of energy-related GHG emissions.
  • 2.1K
  • 23 Nov 2021
Topic Review
The Hydrogen Color Spectrum
Hydrogen production involves different resources and energy loads, depending on the production method used. Therefore, the industry has tried to set a classification code for this energy carrier. This is done by using colors that reflect the hydrogen production method, the resources consumed to produce the required energy, and the number of emissions generated during the process.
  • 2.1K
  • 07 Feb 2023
Topic Review
Non-Intrusive Load Monitoring
Non-intrusive load monitoring (NILM) is a process of estimating operational states and power consumption of individual appliances, which if implemented in real-time, can provide actionable feedback in terms of energy usage and personalized recommendations to consumers. Intelligent disaggregation algorithms such as deep neural networks can fulfill this objective if they possess high estimation accuracy and lowest generalization error. In order to achieve these two goals, this paper presents a disaggregation algorithm based on a deep recurrent neural network using multi-feature input space and post-processing. First, the mutual information method was used to select electrical parameters that had the most influence on the power consumption of each target appliance. Second, selected steady-state parameters based multi-feature input space (MFS) was used to train the 4-layered bidirectional long short-term memory (LSTM) model for each target appliance. Finally, a post-processing technique was used at the disaggregation stage to eliminate irrelevant predicted sequences, enhancing the classification and estimation accuracy of the algorithm. A comprehensive evaluation was conducted on 1-Hz sampled UKDALE and ECO datasets in a noised scenario with seen and unseen test cases. Performance evaluation showed that the MFS-LSTM algorithm is computationally efficient, scalable, and possesses better estimation accuracy in a noised scenario, and generalized to unseen loads as compared to benchmark algorithms. Presented results proved that the proposed algorithm fulfills practical application requirements and can be deployed in real-time.
  • 2.1K
  • 28 Oct 2020
Topic Review
CeO2-based transition metal catalysts
The rational design and fabrication of highly-active and cost-efficient catalytic materials constitutes the main research pillar in catalysis field. In this context, the fine-tuning of size and shape at nanometer scale can exert an intense impact not only on the inherent reactivity of catalyst’s counterparts but also on their interfacial interactions, opening up new horizons for the development of highly active and robust materials. The main implications of ceria nanoparticles’ shape engineering (rods, cubes, polyhedra) in catalysis are revealed, on the ground of some of the most pertinent heterogeneous reactions, such as CO2 hydrogenation, CO oxidation, and N2O decomposition. It is clearly revealed that shape functionalization can remarkably affect the intrinsic features and in turn the reactivity of ceria nanoparticles. More importantly, by combining ceria nanoparticles (CeO2 NPs) of specific architecture with various transition metals (e.g., Cu, Fe, Co, Ni) remarkably active multifunctional composites can be obtained due mainly to the synergistic metal-ceria interactions, providing the design principles of earth-abundant metal oxide catalysts for various real-life environmental and energy applications.
  • 2.1K
  • 22 Apr 2021
Topic Review
Wave Energy in the Mediterranean
The installed power of the several deployed WECs in the Mediterranean Sea varies between 3–2500 kW. Ten project cases of deployed WECs in the basin are presented, with their analysis of the essential features. Five different types of WEC have already been tested under real environmental conditions in Italy, Greece, Israel and Gibraltar, with Italy being the Mediterranean country with the most deployed WECs. The main questions of the relevant studies were the ongoing trends, the examination of WECs in combination with other renewable sources, the utilising of WECs for desalination, and the prospects of wave energy in the Mediterranean islands and ports.
  • 2.1K
  • 12 Aug 2021
Topic Review
Concentrating Photovoltaic—Thermal Systems
Numerous numerical and experimental studies have been conducted regarding the Concentrated Photovoltaic Thermal (CPVT) system because of its significant potential for efficient conversion of solar energy. The overall efficiency of the CPVT system is strongly dependent on the device, which extracts excess heat from photovoltaic cells. The most efficient cooling technology involves active cooling, which means that heat is collected from the photovoltaic (PV) cell via the forced flow of heat transfer fluid.
  • 2.0K
  • 14 Sep 2022
Topic Review
Commercial Development in Carnot Battery Technology
Carnot batteries are a quickly developing group of technologies for medium and long duration electricity storage. It covers a large range of concepts which share processes of a conversion of power to heat, thermal energy storage (i.e., storing thermal exergy) and in times of need conversion of the heat back to (electric) power.
  • 2.0K
  • 08 Feb 2022
Topic Review
Types of Airborne Wind Energy Systems
Airborne wind energy (AWE) has received increasing attention, with the goal of achieving electricity generation solutions that may be used as a complement or even an alternative to conventional wind turbines. There are several ways to classify AWE systems, e.g., with respect to the means of electricity generation, the flight principles and operation, or the type of flying wing, to name a few. 
  • 2.0K
  • 10 Jan 2023
Topic Review
Thin-Film Fabrication for Low-Temperature Solid Oxide Fuel Cells
Solid oxide fuel cells (SOFCs) are amongst the most widely used renewable alternative energy systems with near-zero carbon emission, high efficiency, and environment-friendly features. However, the high operating temperature of SOFCs is still considered a major challenge due to several issues regarding the materials’ corrosion, unwanted reactions between layers, etc. Thus, low-temperature SOFCs (LT-SOFCs) have gained significant interest during the past decades. Despite the numerous advantages of LT-SOFCs, material selection for each layer is of great importance as the common materials have not shown a desirable performance so far. In addition to the selection of the materials, fabrication techniques have a great influence on the properties of the SOFCs. As SOFCs with thinner layers showed lower polarisation resistance, especially in the electrolyte layer, different thin-film fabrication methods have been employed, and their effect on the overall performance of SOFCs has been evaluated.
  • 2.0K
  • 23 Aug 2023
Topic Review
Solar Energy Systems into Seawater Desalination
Solar energy, amongst all renewable energies, has attracted inexhaustible attention all over the world as a supplier of sustainable energy. The energy requirement of major seawater desalination processes such as multistage flash (MSF), multi-effect distillation (MED) and reverse osmosis (RO) are fulfilled by burning fossil fuels, which impact the environment significantly due to the emission of greenhouse gases. The integration of solar energy systems into seawater desalination processes is an attractive and alternative solution to fossil fuels. 
  • 2.0K
  • 29 Sep 2022
Topic Review
VI-based Inverters
The transition from the synchronous generator (SG)-based conventional power generation to converter-based renewable energy sources (RES) deteriorates the frequency stability of the power system due to the intermittency of wind and photovoltaic (PV) generation. Unlike conventional power generation, the lack of rotational inertia becomes the main challenge to interface RES with the electrical grid via power electronic converters. In the past several years, researchers have addressed this issue by emulating the behavior of SG mathematically via pulse width modulation (PWM) controller linked to conventional inverter systems. These systems are technically known as VI-based inverters, which consist of virtual synchronous machine (VSM), virtual synchronous generator (VSG), and synchronverter.
  • 2.0K
  • 30 Oct 2020
Topic Review
Solar Photovoltaic in Kenya
PV technology has advanced significantly in the last decade and this has presented new opportunities in most economies but with attendant challenges. This topic review explores, from a renewable energy system implementation lens, the key barriers and solutions towards increasing the integration of solar PV in Kenya.
  • 2.0K
  • 14 Jan 2021
Topic Review
Carbon Capture and Storage
Carbon capture and storage (CCS) is a developed technology to minimize CO2 emissions and reduce global climate change. Currently, shale gas formations are considered as a suitable target for CO2 sequestration projects predominantly due to their wide availability. However, the injected CO2 causes possible geochemical interactions with the shale formation during storage applications. The CO2/shale interaction is a key factor for the efficiency of CCS in shales, as it can significantly alter the shale properties. This paper reviews the current knowledge of the CO2/shale interactions and describes the results achieved to date, to gain an in-depth understanding of the impact of CO2/shale interaction on shale properties. With this evolving technology, further studies are needed to include various shale formations and identify how different shales’ mineralogy could affect the CO2 storage capacity in the long-term.
  • 2.0K
  • 26 Oct 2020
Topic Review
Refuse Derived Fuel
One viable and robust form of waste-to-energy from municipal solid waste is refuse derived fuel (RDF). Generally, RDF refers to the segregated high calorific fractions of waste from MSW: household, commercial, or industrial process wastes. RDF from municipal solid waste particularly is sorted portions, which consist of combustible components such as waste plastics, paper, cardboard, textiles, and wood.
  • 2.0K
  • 01 Mar 2022
Topic Review
Gas Turbine Power Generation Systems
This paper reviews the modeling techniques and control strategies applied to gas turbine power generation plants. Recent modeling philosophies are discussed and the state-of-the-art feasible strategies for control are shown. Research conducted in the field of modeling, simulation, and control of gas turbine power plants has led to notable advancements in gas turbines’ operation and energy efficiency. Tracking recent achievements and trends that have been made is essential for further development and future research. A comprehensive survey is presented here that covers the outdated attempts toward the up-to-date techniques with emphasis on different issues and turbines’ characteristics. Critical review of the various published methodologies is very useful in showing the importance of this research area in practical and technical terms. The different modeling approaches are classified and each category is individually investigated by reviewing a considerable number of research articles. Then, the main features of each category or approach is reported. The modern multi-variable control strategies that have been published for gas turbines are also reviewed. Moreover, future trends are proposed as recommendations for planned research.
  • 2.0K
  • 28 Jul 2020
Topic Review
Chlorella vulgaris Biomass
Chlorella vulgaris biomass means the biomass made of Chlorella vulgaris, which is a kind of microalgae. Under appropriate conditions, microalgae convert solar energy into chemical energy stored as starch or lipids, which are precursors for bioethanol and biodiesel production. Given the higher photosynthetic efficiency, higher biomass production per unit area and faster growth rate compared to energy crops, microalgae are good alternative as feedstock for biofuel production. An additional advantage of microalgae is the lack of competition for nutrients with food crops. Furthermore, biomass production can be located on marginal lands. The negative environmental impact associated with the cultivation of microalgae for energy purposes is described as potentially negligible.
  • 2.0K
  • 10 Sep 2021
Topic Review
Prospects of Using Hydrogen–Methane Blends
The use of methane–hydrogen mixtures in internal combustion engines improves their performance and emission characteristics. The most important aspect is the concentration of hydrogen in the fuel mixture, which affects the combustion process of the fuel and determines the optimal operating conditions of the engine. When using methane–hydrogen mixtures with low hydrogen content, the safety measures and risks are similar to those that exist when working with natural gas. Serious logistical problems are associated with the difficulties of using the existing gas distribution infrastructure for transporting methane–hydrogen mixtures. 
  • 2.0K
  • 31 Mar 2022
Topic Review
Batteries vs Hydrogen Storage: Complementary or Substitute
Batteries and hydrogen storage technologies are treated as complementary technologies in some cases, but in other ones they are considered opposed technologies. 
  • 2.0K
  • 20 Sep 2022
Topic Review
Hybrid and Electric Vehicles
Even though electric vehicles (EV) were invented over a century ago, their popularity has grown significantly within the last 10 years due to the development of Li-ion battery technology. This evolution created an increase in the fire risk and hazards associated with this type of high-energy battery.
  • 2.0K
  • 08 Feb 2022
Topic Review
Electrolysis of Industrial Wastewater
Water electrolysis is a powerful technology for producing high-purity H2, with negligible emission of greenhouse gases and compatibility with renewable energy sources. Additionally, the electrolysis of organic compounds, such as lignin, is a promising method for localised H2 production, as it requires lower cell voltages than conventional water electrolysis. Industrial wastewater can be employed in those organic electrolysis systems due to their high organic content, decreasing industrial pollution through wastewater disposal. Electrocoagulation, indirect electrochemical oxidation, anodic oxidation, and electro-Fenton are effective electrochemical methods for treating industrial wastewater.
  • 2.0K
  • 27 Apr 2023
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