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 Ganisetti Vijay Kumar  , Min-Ze Lu  and Chang-Ming Liaw

Received: 02 May 2021;  Published: 11 August 2021;  doi: 10.21926/jept.2103037

The development of high-efficiency motor drives for various applications is important in the industry 4.0 era, especially for their extensive application to electric vehicles (EVs). In this study, a position sensorless EV synchronous reluctance motor (SynRM) drive has been developed, which exhibits good driving performance and efficiency over a wide speed and load range. To solve the key problems popularly encountered in the existing approaches, the high-frequency injection (HFI) scheme based on q-axis injection ha [...]

by Clara L.e Silva  , Bárbara H.S. Miranda  , Maria L. Vilela  , Jair F. Rodrigues  , Thainá G. Cunha  , Jhonatan A. Dias  , Gabriela A. Soares  , Vinicius Freitas  , Rodrigo de Q. Vilaça  , Luana Wouk  and Diego Bagnis

Received: 07 March 2022;  Published: 04 July 2022;  doi: 10.21926/jept.2203023

The lifetime and stability of organic photovoltaics (OPVs) are the key factors that influence the technology used to scale up and commercialize OPVs. High-performing and reliable devices are used to fabricate the devices of choice. Materials and methods that can be used to prevent the degradation of organic materials, enabling better OPV applications, are being increasingly researched in recent years. Herein, we present the surface modification process of a commercial, flexible barrier film based on polyethylene te [...]

by Tanja Radu  , Vincent Smedley  , Dipti Yadav  , Richard Blanchard  , Sheik Aminur Rahaman  , P. Abdul Salam  and Chettiyappan Visvanathan

Received: 21 September 2022;  Published: 28 November 2022;  doi: 10.21926/jept.2204039

The implementation of community-level de-centralised anaerobic digestion (AD) systems offers a sustainable solution for organic waste management and energy provision, but there is currently a need for low-cost methods of system control and management at this scale. The problem becomes accentuated with increasing deployment, as greater complexities are created by the need to both monitor and control a wider network of smaller, community-scale plants. This paper describes research to design, deploy and test such a sy [...]

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 Ali Aldubaisi  and Jorge Valenzuela

Received: 26 April 2021;  Published: 04 August 2021;  doi: 10.21926/jept.2103036

Aging models are important input into wind farm maintenance and financial viability models. Aging of wind turbines depends on many factors, including both ambient and usage conditions. This paper presents a virtual age based maintenance model for wind turbines considering the effect of wind speed and ambient air temperature on turbine aging. Two maintenance thresholds (i.e., corrective threshold and preventive threshold) and three repair actions (i.e., unscheduled corrective, scheduled corrective and preventive act [...]

by Zhen Liu  , Li Yang  , Abhishek Lahiri  , James F Rohan  and Frank Endres

Received: 26 December 2021;  Published: 27 March 2022;  doi: 10.21926/jept.2201010

Herein, we report the coating of nanostructured germanium using a polypyrrole (PPy) polymer coat as a composite anode material for the fabrication of lithium-ion batteries. The Ge/PPy composites were synthesized following the direct electrochemical deposition method in an ionic liquid (IL). The results revealed that the coating of PPy on Ge helped realize stable battery cycling and reversible capacities, which were not observed in uncoated Ge. The PPy layers could effectively inhibit side reactions between the elec [...]

by Minghan Bao  , Nagi Abdussamie  and Faisal AlThobiani

Received: 03 December 2022;  Published: 09 February 2023;  doi: 10.21926/jept.2301008

Analysing the structural response of offshore wind turbines (OWTs) requires a robust method to estimate environmental loadings associated with extreme weather conditions. This study aimed to accurately predict wind loadings on a non-rotating OWT using a Computational Fluid Dynamics (CFD) code, Ansys Fluent package. The inlet velocity boundary condition was defined as a uniform inlet wind speed and then as a Normal Wind Profile (NWP). Three large wind speeds of 25 m/s, 40 m/s and 50 m/s were tested with the aid of t [...]

by Alla V. BALUEVA  , Ilia N. Dashevskiy  and Christian Sims

Received: 18 April 2022;  Published: 30 August 2022;  doi: 10.21926/jept.2203028

Due to the increasing need to further develop the world gas and oil industry and the increased public attention to clean energy sources, studying and preventing Hydrogen Induced Cracking is one of the main safety concerns in nuclear power plants, oil pipelines and platforms. In this article, the growth and incubation times for internal Hydrogen Induced Cracks (HIC) are examined. Specifically, these times are modeled in two separate phases - the first phase (I) is a long time approximation, when the crack growth is [...]

by Rajesh Karki  and Binamra Adhikari

Received: 02 April 2024;  Published: 07 August 2024;  doi: 10.21926/jept.2403015

The integration of cyber and physical layer of the grid has not only introduced a microscopic spectacle to observe and ensure the efficient flow of electricity but has also exposed the interdependencies of the network. These cyber-physical interdependencies are often exploited in the form of cyber-attacks that can disable a grid introducing substantial financial losses and observable social repercussions. Thus, it is important to address the impending Achilles heel by devising pragmatic approaches to comprehensibly [...]

by Syuma Ichida  , Daisuke Mori  , Sou Taminato  , Tao Zhang  , Yasuo Takeda  , Osamu Yamamoto  and Nobuyuki Imanishi

Received: 17 February 2022;  Published: 15 March 2022;  doi: 10.21926/jept.2201009

Acidic aqueous lithium-air batteries are attractive candidates for use as energy sources in electric vehicles because of their high energy and power densities and ability to operate under ambient conditions. An aqueous lithium-air battery with an acetic acid catholyte has a high theoretical energy density of 1,478 Wh kg-1, and the reaction product is soluble in the catholyte. In this study, we have studied the cell performance of a Li/interlayer electrolyte/NASICON-type solid lithium-ion conductor/acetic acid catho [...]

by Nicholas J Cook

Received: 14 April 2021;  Published: 25 June 2021;  doi: 10.21926/jept.2102027

A refined and extended version of the Offset Elliptical Normal mixture model has been developed to parameterise the seasonal diurnal wind vector automatically. Automated using R scripts, the method eliminates any potential risk of confirmation bias posed by the manual supervision in the original method. Refinements to the method include the latest algorithms for clustering of Gaussian mixtures, with Bayesian regularisation to set the number of components and to limit the predisposition to overfit. A new extension u [...]

by Kesiena Owebor  , Smith Orode Otuagoma  , Ogheneakpobo Jonathan Eyenubo  , Arthur Gogo Uranta  , Friday Erhimudia Ukrakpor  , Kesiena Ezewu  and Ebimene Ezekiel Ebisine

Received: 01 August 2023;  Published: 08 November 2023;  doi: 10.21926/jept.2304033

The proper management of sawdust is critical to socioeconomic development. In this research, waste-to-energy has been proposed to utilize sawdust in selected timber markets in Port Harcourt, namely, Illoabuchi Timber Market, Marine Base Timber Market, and Mile 3 Timber Market. A quantitative approach has been taken to estimate the sawdust generation, energy potential, power generation capacities, and pollutant reduction of indiscriminate combustion of sawdust. The findings suggest that, annually, 171 ktons, 42 kton [...]

by Andrew Williams  and Murray Thomson

Received: 09 November 2022;  Published: 09 January 2023;  doi: 10.21926/jept.2301003

This paper examines the economic case for the UK to proceed urgently with the installation of thermal insulation and heat pumps in most UK buildings, in the context of the legal requirement to achieve net-zero carbon emissions by 2050. A recent study by the same authors assumed that such insulation and heat pumps would be in place, and showed how the whole of the UK’s energy demand could be met by low carbon electricity generation and appropriate storage. This paper extends the modelling to consider the risk that i [...]

by Efstathios E. Michaelides

Received: 19 April 2021;  Published: 10 September 2021;  doi: 10.21926/jept.2103040

The impending adverse effects of Global Climate Change encourages the substitution of fossil fuels with non-carbon sources for electricity generation. However, while fossil fuel power plants may generate electric power at demand, the most abundant renewable energy sources-wind and solar-are intermittent or periodically variable. This necessitates the development of adequate energy storage at the utility/grid level. Using actual data for the hourly energy demand in the ERCOT electricity grid, this study examines the [...]

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 Abdul G. Khan

Received: 22 July 2021;  Published: 14 December 2021;  doi: 10.21926/jept.2104049

There is growing concern for the contamination of our soils and waters worldwide with heavy metals (HMs), as a result of indiscriminate use of agrochemicals for feeding growing population which require optimal use of resources and sustainable agricultural strategies. This can be simultaneously achieved by using microbes as bio-fertilizers, bio-protectants, and bio-stimulants, and suitable phytoremediation- plant capable of removing heavy metals contaminants from contaminated sites. There is a growing need to adopt [...]

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 Shih-Ang Hsu

Received: 13 December 2020;  Published: 06 July 2021;  doi: 10.21926/jept.2103031

In September 2020 Hurricane Sally affected the north central Gulf of Mexico. Making use of the anemometers data available at 4 oil rigs over the affected region, it is found that, when the atmospheric stability was near-neutral, the gust factor (G) decreases linearly with height from approximately 1.28 at 35m above the sea surface to 1.18 at 160 m. In other words, G decreases linearly at the rate around 8% per 100 m from the typical hub height to beyond common hub height. Based on the linear equation found in this [...]

by Oleksandr Skrylnyk  , Emilie Courbon  , Nicolas Heymans  and Marc Frère

Received: 18 December 2020;  Published: 14 April 2021;  doi: 10.21926/jept.2102017

Hybrid solar thermal systems are considered to be a promising solution for delivering clean thermal energy for the building sector, especially while combining them with other renewable energy sources. Usually, solar energy production does not match the thermal energy demand, and hence the energy storage must be integrated. Thermochemical energy storage is adapted particularly to be used along with solar thermal applications. In this article, the design of the combined solar thermochemical energy storage system is p [...]

by Aniebiet D. Udoh  , Ogheneruona E. Diemuodeke  , Mohammed M. Ojapah  , Fidelis I. Abam  and Joseph C. Ofodu

Received: 29 December 2022;  Published: 13 April 2023;  doi: 10.21926/jept.2302015

The quest to decarbonize the energy space to avert the negative climate change consequences calls for using low/zero-carbon energy conversion technologies in the energy generation space. The Organic Rankine Cycle is a low/zero-carbon energy conversion technology for recovering waste heat from low to medium-temperature heat sources and for biomass conversion. Therefore, this paper presents the thermodynamic optimization, with an artificial bee colony algorithm, of different ORC configurations, including simple organ [...]

by Kenji Amagai  , Hiroto Kotake  , Masahiro Munemura  , Sawako Shigeto  and Masayuki Horio

Received: 10 October 2022;  Published: 02 February 2023;  doi: 10.21926/jept.2301005

This paper describes the development of low-speed electric community buses (LSECBs) designed by the author's group and their spread situation in Japan. LSECBs are electric vehicles that can travel on public roads at speeds of less than 5.56 m/s (20 km/h). The university, local government, local businesses, and residents with a co-design approach developed the LSECBs. They have various advantages such as safety due to low speed and low energy consumption. In particular, the LSECBs have features not found in ordinary [...]

by Hossein Akbari  , Seyed Mojtaba Hosseinnia  , Mikhail Sorin  , Christopher Reddick  and Dominic Laperle

Received: 13 January 2022;  Published: 12 April 2022;  doi: 10.21926/jept.2202013

Heat integration techniques such as pinch analysis can play a significant role in saving energy in the design of buildings. The application of pinch analysis in this sector encounters difficulties due to the highly time-dependent behavior of energy streams such as waste heat and solar thermal collectors, as well as the possible need for heat storage units (HSUs). The existing pinch models in the literature either bear little relation to reality because they ignore the time dependency of the streams, or they do not [...]

by Xiaofei Qin  , Yongren Feng  , Lejun Wu  , Zhongjian Tan  , Yanmin Zhou  and Wilson Chin

Received: 12 April 2023;  Published: 10 July 2023;  doi: 10.21926/jept.2303023

In conventional wireline and LWD/MWD formation testing, downhole predictions for rock and fluid properties are based on simplified Darcy flow models, but only for mathematical expediency. These require initially constant pressures that are uniform throughout the reservoir. This limitation precludes common applications in overbalanced drilling, so that supercharge or near-well invasion effects - associated with rapidly decreasing pressures at the sandface where pressures are measured - are completely ignored. Such 1 [...]

by Gabriela Martínez-Machado  , Laura Arely López-Gámez  , Litzy Yazmin Alvarado-Mata  , Roberto Muñoz-García  , Jenny Priscila Salinas-Mireles  , Ivan Artemio Corral-Guerrero  , Maria Jose Castro-Alonso  , Jazel Doménica Sosa-Martínez  , Miriam Paulina Luévanos Escareño  , Ayerim Yedid Hernández-Almanza  and Nagamani Balagurusamy

Received: 20 February 2025;  Published: 13 May 2025;  doi: 10.21926/jept.2502010

The global production of biomethane is rapidly emerging as a sustainable alternative to fossil fuels for energy generation. Biogas, where methane (CH4) is usually one of the main components, is generated through the anaerobic digestion (AD) of various organic substrates, including animal manure, organic wastes, and wastewater. The efficiency of the AD process depends on key operational parameters and reactor designs that optimize microbial activity and gas yield. However, inhibitory compounds such as heavy metals, [...]