by Arianna Massaro  , Ana B. Muñoz-García  , Mariarosaria Tuccillo  , Michele Pavone  and Pier Paolo Prosini

Received: 02 November 2020;  Published: 10 June 2021;  doi: 10.21926/jept.2102022

The current state-of-the-art quantum mechanics methodologies were applied to derive information on the bulk and surface properties of the P2-type layered oxide Na0.85Li0.17Ni0.21Mn0.64O2 (NLNMO), a cathode material. The special quasi-random structure (SQS) approach was employed to identify the arrangement of Li, Ni, and Mn ions in a supercell containing 115 atoms. Both the cell parameters and atomic positions were determined from DFT-PBE+U calculations to highlight specific distortions induced by the dopants (Ni an [...]

by Han Zhang  and Joseph D. Smith

Received: 09 November 2020;  Published: 30 January 2021;  doi: 10.21926/jept.2101008

Solar thermochemical reactor provides an attractive approach that utilizes the most common solar radiation as the thermal driving force to motivate the reaction between CO2 and metal oxides, which is also called metal oxide redox pair-based thermochemical cycles. The CeO2/CeO2-δ is widely used in the two-step redox process due to its advantages including fast-redox kinetics, high crystallographic stability of a wide range of reacting oxygen non-stoichiometry, and relatively high oxygen solid-state conductivit [...]

by Deewakar Poudel  , Benjamin Belfore  , Shankar Karki  , Grace Rajan  , Sina Soltanmohammad  , Angus Rockett  and Sylvain Marsillac

Received: 28 October 2020;  Published: 06 January 2021;  doi: 10.21926/jept.2101001

The effect of water ingress on the surface of the buffer layer of a Cu(In, Ga)Se2 (CIGS) solar cell was studied. Such degradation can occur either during the fabrication process, if it involves a chemical bath as is often the case for CdS, or while the modules are in the field and encapsulants degrade. To simulate the impact of this moisture ingress, devices with a structure sodalime glass/Mo/CIGS/CdS were immersed in deionized water. The thin films were then analyzed both pre and post water soaking. Dynamic second [...]

by Babkir Ali

Received: 30 May 2019;  Published: 07 August 2019;  doi: 10.21926/jept.1903002

The main objective of this paper is to study the sustainability of power generation from an abandoned oil and gas well in the province of Alberta, Canada. Economic and environmental indicators were used for the sustainability assessment. A conceptual design for a pilot plant was developed, and the main parameters were determined. An abandoned oil and gas well represents the thermal power source through circulating water into an organic Rankine cycle (ORC) unit to generate electricity. The thermal power is extracted [...]

by F.A Hamad  , E. Emenike  , Abbas Mohammed  , S. Gooneratne  and P. Russell

Received: 01 December 2020;  Published: 31 January 2021;  doi: 10.21926/jept.2101009

In this paper, the primary aim is to look at the fundamental melting/solidification processes of polyethylene glycol 1500 (PEG 1500) for energy storage - insulation to prolong the cooling time of pipelines in unexpected shut-down conditions, prevent/minimize the wax deposition, and hydrate formation. Polyethylene glycol 1500 was selected because its melting temperature is >317 K making it a suitable candidate as lagging material to prevent wax deposition and hydrate formation in subsea oil pipelines. Experim [...]

by Chaonan Zhang  , Robert Fuller  and Iyad Hijazi

Received: 10 November 2020;  Published: 25 January 2021;  doi: 10.21926/jept.2101006

The Pd-H system has attracted extensive attention. Pd can absorb considerable amount of H at room temperature, this ability is reversible, so it is suitable for multiple energy applications. Pd-Ag alloys possess higher H permeability, solubility and narrower miscibility gap with better mechanical properties than pure Pd, but sulfur poisoning remains an issue. Pd-Cu alloys have excellent resistance to sulfur and carbon monoxide poisoning and hydrogen embrittlement, good mechanical properties, and broader temperature [...]

by Peter Leary  , Peter Malin  , Graeme Saunders  and Charles Sicking

Received: 03 December 2019;  Published: 29 July 2020;  doi: 10.21926/jept.2003012

A core feature of convective geothermal resource production is wellbore energy flow Q ~ ρC x T x V. E.g., for wellbore fluid of volume heat capacity ρC ~ 4.3MJ/m3.oC, temperature T ~ 230oC, and volumetric flow V ~ 50L/s, wellbore heat energy production is Q~ 50MWth ~ 5MWe. Wellbore fluid flow V =2πr0ϕv0ℓ for open wellbore length ℓ is given in turn by the spatially variable product crustal porosity times crustal fluid velocity v ≡ ϕv0 at the wellbore rad [...]

by Aly Mousaad Aly  and Milad Rezae

Received: 26 December 2020;  Published: 04 March 2021;  doi: 10.21926/jept.2101011

During their lifecycle, wind turbines can be subjected to multiple hazard loads, such as high-intensity wind, earthquake, wave, and mechanical unbalance. Excessive vibrations, due to these loads, can have detrimental effects on energy production, structural lifecycle, and the initial cost of wind turbines. Vibration control by various means, such as passive, active, and semi-active control systems provide crucial solutions to these issues. We developed a novel control theory that enables semi-active controller tuni [...]

by Najmul Hoque  , Wahidul Biswas  , Ilyas Mazhar  and Ian Howard

Received: 29 June 2020;  Published: 31 July 2020;  doi: 10.21926/jept.2003013

Hydrogen is regarded as a potential solution to address future energy demands and environmental protection challenges. This study assesses the triple bottom line (TBL) sustainability performance of hydrogen as an automotive fuel for Western Australia (WA) using a life cycle approach. Hydrogen is considered to be produced through water electrolysis. Two scenarios, current grid electricity and future renewable-based hydrogen, were compared with gasoline as a base case. The results show that locally produced grid elec [...]

by Kosmas A. Kavadias  and Stefanos Tzelepis

Received: 03 June 2020;  Published: 24 July 2020;  doi: 10.21926/jept.2003011

The fluctuations in the cost of energy coupled with the gradual decrease in natural resources (i.e., oil, natural gas, coal) and the environmental issues caused by the extensive use of fossil fuels, demand the urgent need for the development of advanced and clean energy systems. The European Union has requested new measures to target climate and energy deterioration by developing renewable energy sources by 2030. The stochastic character of the energy sources and the fluctuation in demand for the energy systems pos [...]

by Babkir Ali

Received: 23 May 2019;  Published: 23 July 2019;  doi: 10.21926/jept.1903001

This paper is intended to evaluate the economic viability of producing solar photovoltaic modules in Sudan. The simple payback period and the net present value were used as economic indicators to study comparatively different annual production capacities. Initial and operating costs were developed and analyzed for the product lifecycle. The number of working shifts in the base case is doubled to achieve a production rate of 20 MW/year and double shift with double quantity of machines is executed to reach a producti [...]

by Steven Hespeler  and Donovan Fuqua

Received: 31 July 2020;  Published: 12 January 2021;  doi: 10.21926/jept.2101003

This investigation presents a data-driven Long-short Term Memory battery model for predicting State of Charge for lithium-ion batteries LiFePO4 for next-generation vehicle operations. Our modified algorithm builds and updates a model using multivariate inputs that include physical properties, voltage, current, and ambient temperature during operations. The primary research goal is to improve prediction performance on future values from multiple training examples using an online learning scheme. Initial results demo [...]

by Floris Taminiau  and Bob van der Zwaan

Received: 04 August 2022;  Published: 10 October 2022;  doi: 10.21926/jept.2204032

In the Netherlands, an important way to contribute toward achieving climate goals is the large-scale deployment of wind turbines in the North Sea. The North Sea is a unique location for offshore wind power thanks to its strong winds, shallow waters, and proximity to large energy users. Wind turbines generate electricity by extracting kinetic energy from the atmosphere. This kinetic energy is replenished at a finite rate through the mixing of atmospheric layers. The replenishment rate sets a physical limit to the am [...]

by Shih-Ang Hsu

Received: 16 April 2021;  Published: 16 June 2021;  doi: 10.21926/jept.2102025

During a tropical cyclone (TC) worldwide, the Regional and Mesoscale Meteorological Branch (RAMMB) of NOAA/NESDIS (http://rammb.cira.colostate.edu/) issues real-time TC surface wind analyses. The purpose of this article is to provide value-added estimations of several meteorological and oceanographic (met-ocean) parameters including overwater friction velocity and turbulence intensity, variation of the wind speed with height, significant wave height, peak or dominant wave period, wind-driven currents and wind-stres [...]

by Yi-Chun Hsu  , Min-Ze Lu  and Chang-Ming Liaw

Received: 18 December 2020;  Published: 28 April 2021;  doi: 10.21926/jept.2102018

This paper proposes a Wind Turbine Emulator (WTE) using an Indirect Field Oriented (IFO) Induction Motor (IM). The IM drive can be controlled as a conventional prime mover in speed mode, or a wind turbine in torque-speed mode via robust observed torque control. This paper presents key issues for establishing a high-performance IFO IM drive. Further, this study develops a wind turbine load Interior Permanent-Magnet Synchronous Generator (IPMSG) followed by a three-phase Vienna Switch-Mode Rectifier (SMR). It receive [...]

by Mohammad Jafari  and Zahra Malekjamshidi

Received: 13 June 2020;  Published: 05 August 2020;  doi: 10.21926/jept.2003014

In this paper, a topology of a residential hybrid renewable energy system based on a high-frequency multi-winding transformer is introduced and analyzed. The system includes a PV and a wind-turbine as renewable energy sources, a battery as energy storage and their energies are integrated through a high-frequency transformer. In fact, the transformer integrates the energies in a magnetic form and also isolates the system inputs and outputs. The integrated output from renewables and battery is a DC high-voltage and i [...]

by Max F. Platzer  and Nesrin Sarigul-Klijn

Received: 28 January 2020;  Published: 29 April 2020;  doi: 10.21926/jept.2002005

The current status of a project is described which aims to demonstrate the technical and economic feasibility of converting the vast wind energy available over the globe’s oceans and lakes into storable energy. To this end, autonomous high-performance sailing ships are equipped with hydrokinetic turbines whose output is stored either in electric batteries or is fed into electrolysers to produce hydrogen which then is compressed and stored in tanks. In the present paper, the previous analytical studies which showed [...]

by Brian D. Barkdoll

Received: 26 May 2023;  Published: 21 November 2023;  doi: 10.21926/jept.2304037

Global climate change has necessitated the reduction of GHG emissions. Water distribution system (WDS) pumping adds to these emissions and, therefore, should be reduced. Under electricity hourly cost tariffs, utilities are incentivized to pump during the nighttime hours. This can have a deleterious effect, however, on GHG emissions. To quantify this effect, a modeling study of twelve real WDSs was performed with an electricity tariff. The systems all had the typical tank-level-based pump controls but also time-base [...]

by Jacob Ladenburg

Received: 28 April 2020;  Published: 12 August 2020;  doi: 10.21926/jept.2003015

Visual external costs are significant elements in the cost-benefit analysis of wind farm locations. This has been demonstrated well in the literature. However, in the assessment of the visual costs, a large share of the earlier studies used no or only simplistic visualizations of the visual impacts at stake. The cost estimates thus rely on the respondents’ ability to imagine the visual impacts associated with wind turbines of different sizes and at different locations. This has been argued to potentially reduce the [...]

by Hironari Minami  , Hiroaki Izumi  , Takumi Hasegawa  , Fan Bai  , Daisuke Mori  , Sou Taminato  , Yasuo Takeda  , osamu yamamoto  and Nobuyuki Imanishi

Received: 30 June 2021;  Published: 23 September 2021;  doi: 10.21926/jept.2103041

Rechargeable batteries with higher energy and power density exceeding the performance of the currently available lithium-ion batteries are suitable for application as the power source in electric vehicles (EVs). Aqueous lithium-air batteries are candidates for various EV applications due to their high energy density of 1910 Wh kg-1. The present study reports a rechargeable aqueous lithium-air battery with high power density at room temperature. The battery cell comprised a lithium anode, a non-aqueous anode electro [...]

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 Marco Antonio Gaya de Figueiredo  , Luiza G. dos Santos  , Rômulo Luciano Nascimento  and Harrison Lourenço Corrêa

Received: 18 April 2024;  Published: 11 November 2024;  doi: 10.21926/jept.2404020

Hydrogen is crucial in various industrial sectors and can be obtained through different synthesis routes. However, a significant portion of its production still relies on chemical processes involving fossil fuels, resulting in hydrogen and the generation of greenhouse gases (GHGs) as the final byproduct. In alignment with the goals of the 2030 Agenda, where countries commit to implementing energy transition, hydrogen obtained through a green route has been increasingly explored by governmental and academic entities [...]

by Xiang Li  , Yuan Xue  , Ryan Dehoff  , Costas Tsouris  and Patricia Taboada-Serrano

Received: 09 April 2020;  Published: 09 May 2020;  doi: 10.21926/jept.2002007

Hierarchically-structured, electro-catalysts consisting of a titanium core with controlled macro-porosity and a thin titania surface-layer with controlled nano-porosity were synthesized via combination of additive manufacturing and in-situ anodization. The electrodes were tested for hydrogen evolution reaction and depicted competitive electro-catalytic activities, with Tafel slopes between 40 and 56 mV dec-1. The electrodes also depicted competitive onset and over potentials when compared with other electrode alter [...]

by Akira Nishimura  , Satoshi Ohata  , Kaito Okukura  and Eric Hu

Received: 25 March 2020;  Published: 14 May 2020;  doi: 10.21926/jept.2002008

Biogas is a promising resource for the production of H2 since it liberates energy by recycling waste, along with the reduction of CO2. In this paper, the biogas dry reforming membrane reactor is proposed to produce H2 for use in fuel cells. Pd/Cu alloy membrane is used to enhance the performance of the biogas dry reforming reactor. This study aims at understanding the effect of operating parameters such as feed ratio of sweep gas, pressure in the reactor, and reaction temperature on the performance of the biogas dr [...]

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 [...]