by Abdullah Abbas Kendoush

Received: 04 October 2021;  Published: 07 December 2021;  doi: 10.21926/jept.2104048

By the adoption of a drag-buoyancy equality model, analytical solutions were obtained for the drag coefficients (CD) of Taylor bubbles rising steadily in pipes. The obtained solutions were functions of the geometry of the Taylor bubble and the gas volume fraction. The solutions were applicable at a wide range of Capillary numbers. The solution was validated by comparison with experimental data of other investigators. All derived drag formulas were subject to the condition that Bond number >4, for air-water syste [...]

by Bertrand Cassoret  and François Balavoine

Received: 20 September 2024;  Published: 30 April 2025;  doi: 10.21926/jept.2502008

This study focuses on the environmental impacts of the electricity production scenarios proposed for France for 2060 by the French electricity network manager, RTE. They consider an increasing electricity consumption and a production without fossil fuels, essentially based on wind, photovoltaic, hydraulic, and, for some, nuclear power. The total power to install is significantly higher than the current one; it is higher in the scenarios that rely more on photovoltaic and less on nuclear. Renewable energies require [...]

by Jamie A. Chin  and Wilson C. Chin

Received: 12 February 2022;  Published: 23 May 2022;  doi: 10.21926/jept.2202018

Flows in multi-branch piping systems are modeled for linear Newtonian and nonlinear Power Law, Bingham Plastic and Herschel-Bulkley fluids. The nonlinear models are often used to describe multiphase fluids consisting of liquid and solid phases, including cement slurries and drilling muds in petroleum engineering. Rheological and heterogeneous multiphase effects are important to blood flows in single and bifurcated arteries, capillaries and veins – biological applications are also emphasized to highlight their incre [...]

by Jazael Ballina  and Yun Ii Go

Received: 15 September 2024;  Published: 02 January 2025;  doi: 10.21926/jept.2501001

Performance degradation, including system deterioration, corrosion, and energy loss in solar PV systems, can be caused by environmental conditions such as high humidity, frequent rainfall, and temperature swings in tropical nations. Over the years, photovoltaic energy has been successfully developed to have low production costs and high efficiency. It has been the main reason that solar energy is one of the fastest-growing renewable energies in the world, with a generation of 821 TWh of electricity since 2021, repr [...]

by Owen Sedej  , Eric Mbonimpa  , Trevor Sleight  and Jeremy Slagley

Received: 18 February 2022;  Published: 18 August 2022;  doi: 10.21926/jept.2203027

Waste-to-Energy technologies have the potential to dramatically improve both the natural and human environment. One type of waste-to-energy technology that has been successful is gasification. There are numerous types of gasification processes and in order to drive understanding and the optimization of these systems, traditional approaches like computational fluid dynamics software have been utilized to model these systems. The modern advent of machine learning models has allowed for accurate and computationally ef [...]

by Andrew Williams  and Murray Thomson

Received: 25 September 2022;  Published: 13 December 2022;  doi: 10.21926/jept.2204041

This paper sets out a quantified scenario for the UK to reach net zero carbon emissions. Wind and solar are the main energy sources and their intermittency is accommodated through hydrogen electrolysis, biogas from anaerobic digesters, and their combination into biomethane. Hydrogen and biomethane stocks are tracked. A daily energy balance model is presented, using the most recent recorded weather data-2017 to 2021. Long periods of low wind in 2021 indicated the necessary energy storage capacities, which were adjus [...]

by Marzouk lajili

Received: 05 November 2021;  Published: 19 January 2022;  doi: 10.21926/jept.2201005

The emission of greenhouse gases, specifically CO2, has reached non-acceptable levels causing global warming with adverse effects. Owing to rigorous ongoing research, these harmful substances might be converted to beneficial sources. The main objective of this study was to review the most effective processes that might utilize carbon dioxide to produce various substances, chemicals, and energy. For this, different existing and projected short-term and long-term strategies have been presented and discussed. Specific [...]

by Gilbert Ahamer

Received: 07 December 2023;  Published: 13 May 2024;  doi: 10.21926/jept.2402011

The present need for an energy transition in the wake of a global climate catastrophe led to the “EU green deal” which requires a transition of the energy system in all countries. This study aimis survey aims to identify strategies within such an energy transition based on global trend analyses and reports on available technologies for implementation. Based on a literature analysis of over 300 pieces (of feasibility studies and technology implementation reports with a focus on Central Europe) and a statistical anal [...]

by Tyler Campbell  and Sergey Stolbov

Received: 16 February 2020;  Published: 20 April 2020;  doi: 10.21926/jept.2002003

In the search for new efficient photo-catalysts for hydrogen production through water splitting, the main attention has been paid to tuning the band gap width and its position with respect to vacuum level. However, actual electro-catalytic activity for the water oxidation reaction on a catalyst surface is no less important than those quantities. In this work we evaluate from first principles the thermodynamics of the reaction on relatively new candidates for water splitting: two-dimensional C2N and that doped with [...]

by Mohsen Pourfallah  and Ethan Languri

Received: 19 October 2024;  Published: 15 January 2025;  doi: 10.21926/jept.2501003

Parabolic trough collectors (PTCs) are essential for solar thermal energy systems, and their thermal efficiency can be significantly enhanced using turbulators and nanofluids. This numerical study introduces three novel fin-spiral turbulator configurations (4, 7, and 10 blades) to enhance heat transfer within the absorber tube. Additionally, three nanofluid types including water-based single-walled carbon nanotubes (SWCNT), cupric oxide (CuO), and a hybrid SWCNT-CuO, at concentrations of 1%, 3%, and 5% were evaluat [...]

by Ryan J. Clarke  and David A. Miller

Received: 15 April 2020;  Published: 09 June 2020;  doi: 10.21926/jept.2002010

As wind turbine blades grow longer, new design parameters gain additional importance such as blade weight, tip deflection and material cost. These parameters require designers to relook at carbon fiber as a potential design solution. However, the composite materials in wind turbine blades are subjected to significant compressive loading, and the compressive strength of carbon fiber reinforced polymer (CFRP) composites is much lower than its tensile strength. This reduction in compression strength is due to a change [...]

by Cherechi Ndukwe  , M. Tariq Iqbal  , Jahangir Khan  and Mohsin Jamil

Received: 18 April 2022;  Published: 26 June 2022;  doi: 10.21926/jept.2202022

One important aspect toward proper and stable functioning of a communication-based controlled microgrid is data transmission. Consequently, an analysis of the effect of data transmission delay is of significance for any chosen communication protocol. This paper focuses on the effect of employing LoRa for data transfer at the secondary control level of a standalone DC microgrid. It analyses the effect of LoRa transmission delay on the dynamic performance of DC microgrids. This paper simulates a community DC microgri [...]

by Aurore Raoux  , Ilan Robin  , Jean-Philippe Pezy  , Anne-Claire Bennis  and Jean-Claude Dauvin

Received: 08 October 2020;  Published: 17 March 2021;  doi: 10.21926/jept.2101012

The French coast of the Atlantic and English Channel (EC) is promising for the development of Marine Renewable Energy (MRE), including wind, wave, and tidal stream, due to the high velocity of currents in some parts of the area. This paper, focusing on wind and tidal energy, discusses how the implementation of MRE converters influences biodiversity, and vice versa, through biofouling and reef effects. The understanding of these interactions requires the knowledge of the hydro-sedimentary conditions and the macrofau [...]

by Ken Shimomukai  , Haruka Maeda  , Zahirah binti Muhammad Azman  , Sandro Sitompul  and Goro Fujita

Received: 09 March 2023;  Published: 03 August 2023;  doi: 10.21926/jept.2303026

One way to increase solar photovoltaic penetration in the grid is the management of voltage fluctuations. This is because a photovoltaic plant cannot be interconnected to the grid if it causes voltage violations. Voltage violation is where voltage exceeds the acceptable range. Often, grid operators request photovoltaic plant owners to regulate voltage sufficiently with expensive and space-consuming static Var compensators. Unfortunately, this sometimes makes the project less feasible. This paper argues that there a [...]

by Koorosh Goudarzi  and AliReza R. Taghizadeh

Received: 31 December 2022;  Published: 06 February 2023;  doi: 10.21926/jept.2301006

In this paper, due to the importance of energy recovery from internal combustion engines and the increasing human growing need for power and refrigeration, a two-cycle power and refrigeration system consisting of an organic Rankine cycle and an ejector refrigeration cycle is investigated analytically. The proposed system with the ability to use the ejector as an effective and economical system, can produce simultaneous power and refrigeration by drawing thermal energy from the exhaust gas and engine coolant in the [...]

by Xiang-Yu Sun  , Ping-Hong Jhou  , Min-Ze Lu  and Chang-Ming Liaw

Received: 25 February 2021;  Published: 22 June 2021;  doi: 10.21926/jept.2102028

This paper presents the development of a wind Interior Permanent-Magnet Synchronous Generator (IPMSG) based bipolar DC microgrids along with various switch-mode rectifiers. Firstly, the wind IPMSG is established and adequately controlled to possess satisfactory generating characteristics during different driven speeds and loads. Later, the boost switch-mode rectifier (SMR) based bipolar DC bus is established. Further, three-phase single-switch (3P1SW) boost SMR, three-phase two-switch (3P2SW) three-level boost SMR, [...]

by Vincent Anayochukwu Ani

Received: 06 August 2023;  Published: 24 January 2024;  doi: 10.21926/jept.2401002

Energy is a prerequisite to running health facilities and is, therefore, key to the success of the service. Karshi primary healthcare centre (PHC) facility is confronted with an unreliable power supply that leads to a high cost of generating power from diesel to operate its equipment. This facility needs a sustainable and reliable electricity supply and therefore a change in their energy system to enable it improve its quality of healthcare delivery services. A solar energy-based electricity generation system that [...]

by Peter Newman  and Marie Verschuer

Received: 27 February 2023;  Published: 17 November 2023;  doi: 10.21926/jept.2304036

The transition to net zero cities is a pivotal challenge in the face of climate change. This research introduces a novel methodology termed "Net Zero Corridors," which emphasizes a bottom-up approach to decarbonize urban power and transport systems. By focusing on urban corridors, this method integrates distributed power systems with urban transport, offering a localized solution to the broader challenge of urban decarbonization. Drawing from urban fabric theory and urban metabolism data, the study provides insight [...]

by Kenji Morita  and Bun Tsuchiya

Received: 26 March 2021;  Published: 24 June 2021;  doi: 10.21926/jept.2102029

In this review, various studies on the Li depth profiles of metal/electrolyte/metal capacitors and batteries of Au/LCO/LATP/Pt, LCO/LiPON/Si, and LMO/LiPON/NbO with different metal electrodes at both sides (by bias; LCO =LiCoO2, LATP =Li3.1Al0.86Ti1.14Ge1.27P1.73O12, LMO =LiMn2O4, NbO = Nb2O5) using the in-situ reflection ERD (ERD) technique with 9MeV O+4 ion beam and transmission ERD (TERD) technique with 5MeV He+2 ion beam, respectively, are described. For capacitors, the transport fraction of Li-ion in the elect [...]

by Mikhail Granovskiy

Received: 17 October 2023;  Published: 14 November 2023;  doi: 10.21926/jept.2304034

According to the United States Department of Energy, waste heat recovery would allow up to a 20% reduction in greenhouse gases (GHG) emission. Most of the waste energy is discharged as a low-grade heat at temperatures less than 250°C. Therefore, the development of new technologies and the enhancement of existing ones to convert low-grade heat into electrical or mechanical energy are of great importance. The working principle of adsorption-desorption heat pumps with cyclic switching between adsorption and desorp [...]

by Chen-Wei Yang  , Min-Ze Lu  , Wei-Ming Ma  and Chang-Ming Liaw

Received: 23 December 2020;  Published: 07 April 2021;  doi: 10.21926/jept.2102016

This paper presents a three-phase full-bridge boost switch-mode rectifier (SMR) fed switched-reluctance motor (SRM) drive with energy storage buffer. First, the power circuits and control schemes of the two power stages are properly designed. Except for having good line drawn power quality, the boostable DC-link voltage of the SRM drive can enhance the SRM driving performance in wide speed range. And the recovered regenerative braking energy can be sent back to the grid successfully. Then, a battery storage system [...]

by Meenal Jain  , Meenakshi Mital  and Matt Syal

Received: 21 November 2021;  Published: 14 April 2022;  doi: 10.21926/jept.2202014

India is a rapidly developing nation and is heavily dependent on fossil fuels. Renewable energy presents an attractive solution to the growing challenges concerning energy needs. Solar energy is abundant in India, and thus, its application and use are rapidly advancing. This study assesses various government initiatives for off-grid Solar Photovoltaic/Solar Water Heating systems for commercial establishments in India and elucidates the need for improvements in their implementation, highlighting the problems in avai [...]

by Zeel Maheshwari  and Rama Ramakumar

Received: 29 August 2021;  Published: 21 January 2022;  doi: 10.21926/jept.2201006

Rural and remote communities are more vulnerable to damage caused by extreme events as compared to urban areas. Natural disasters can disrupt basic supplies such as domestic water supply and cooking needs in addition to electricity outages. The recognition of the interlinked nature of food, water and energy has gained momentum over the past few years. Smart Integrated Renewable Energy System (SIRES) has been proposed to handle basic needs such as cooking, domestic and irrigation water supply, and electricity to rem [...]

by Sadmanul Hoque  , Md. Rashidul Islam  , Md Shafiullah  , Saymun Adnan  and Md. Samiul Azam

Received: 18 June 2023;  Published: 28 September 2023;  doi: 10.21926/jept.2303030

In an electric power system operation, the main goal of economic dispatch (ED) is to schedule the power outputs of committed generating units efficiently. This involves consideration of relevant system equality and inequality constraints to meet the required power demand at the lowest possible operational cost. This is a challenging optimization problem for power system operators that can be dealt with efficient meta-heuristic algorithms. This article uses a recent meta-heuristic approach named the generalized norm [...]

by Reinhard Haas  , Marina Siebenhofer  , Jakob Lederer  and Amela Ajanovic

Received: 24 June 2022;  Published: 27 September 2022;  doi: 10.21926/jept.2203030

Today, the building sector poses a major problem concerning fossil fuel energy consumption and the corresponding emissions of local pollutants and global greenhouse gases (GHG). In addition, an increasing number of people are living in urban areas, and it is becoming challenging to provide the necessary living space and energy for heating in fast-growing cities. Currently, urban areas host approximately 50 % of the global population and generate 70 % of GHG. The core objective of this study is to analyze the histor [...]