by Mosebetsi J. Leotlela

Received: 21 April 2025;  Published: 19 December 2025;  doi: 10.21926/jept.2504018

The effective neutron multiplication factor (keff) of a fissile system is a function of space and time f(x, y, z, t), where (x, y, z) are the coordinates of the reference point in space, and t is time. The evidence of the time-dependence of the neutron multiplication factor of a fissile system was published in 2017. The spatial dependence is as important as the time dependence, as interacting arrays of fissile material during storage can lead to an increase in the system (keff). Therefore, evaluation of how the sto [...]

by Chuan-Tsung Lee

Received: 15 September 2025;  Published: 10 December 2025;  doi: 10.21926/jept.2504017

Taiwan relies heavily on imported fossil fuels, with over 98% of its energy demand supplied by foreign sources, posing significant challenges to national energy security. To explore alternatives, this study investigates the potential of marine renewable energy by developing a 20 kW floating hydrokinetic turbine prototype designed for deployment in the Kuroshio Current. The research encompasses system design, model validation, and both tank and at-sea testing to evaluate hydrodynamic performance and power generation [...]

by Divya Mobarsa  , Kedar Mehta  , Amit Sata  and Minal Shukla

Received: 11 June 2025;  Published: 05 December 2025;  doi: 10.21926/jept.2504016

This research introduces a blockchain framework to improve security and transparency for the use of renewable energy in power systems. The framework utilizes a permissioned blockchain architecture and IoT-based real-time monitoring to ensure data integrity and confidentiality and support efficient peer-to-peer (P2P) energy trading. Compared with traditional centralized energy management systems, the proposed design increases transaction security by 35%, decreases verification wait times by 28%, and decreases the ri [...]

by Alioune Diouf  , Yasuhiro Noro  and Fujita Goro

Received: 17 June 2025;  Published: 24 October 2025;  doi: 10.21926/jept.2504015

Recently, renewable energy projects using storage systems have gained significant attention. This innovative technology requires a comprehensive investigation to overcome the technical and economic issues, which are related to optimal storage system capacity and operational requirements. In this study, an extensive battery energy storage system (BESS) sizing method was proposed considering four variables: charging and discharging scheduling, state of charge, BESS rate energy and power capacity, and degradation effe [...]

by Nanimpo Kansongue  , Stephen Vertigans  and James Njuguna

Received: 22 December 2024;  Published: 13 October 2025;  doi: 10.21926/jept.2504014

This work investigates the potential of renewable energy to significantly reduce Togo’s energy deficit, offering a critical analysis of the country’s current energy landscape. It evaluates the availability and viability of renewable energy sources—particularly solar and small-scale hydropower—and examines the mismatch between energy supply and growing demand. The study highlights Togo’s heavy reliance on biomass and energy imports from neighbouring countries such as Ghana, Côte d’Ivoire, and Nigeria, which exacerba [...]

by Anudeep Katepalli  , Thiraj Mohankumar  , Meher Saketh Gandharapu  , Sagar Shrestha  , Anton Harfmann  , Mathias Bonmarin  , John Krupczak  and Donglu Shi

Received: 06 July 2025;  Published: 11 September 2025;  doi: 10.21926/jept.2503013

Indoor environments offer a unique opportunity for photon recycling using LED-based illumination, particularly to address energy limitations of solar photovoltaic (PV) systems during nighttime or in low-light conditions. This study presents an optical and electrical performance evaluation of silicon-based photovoltaic (SPV) panels operating under controlled indoor LED lighting. Despite the low irradiance (~1.4 mW/cm2), significant power output was achieved through engineered panel configurations and optimized light [...]

by Franco David Hessling Herrera

Received: 01 May 2025;  Published: 25 August 2025;  doi: 10.21926/jept.2503012

The tariff policy for energy services is a fundamental issue for today's societies, especially for end users, including residential, commercial, and industrial. The main objective of this paper is to propose a statistical method to calculate, compare, and evaluate policies of this nature. To this end, firstly, it is intended to rethink an old concept on this type of policy, the principle of fairness and reasonableness, through the linkage with the perspective of human rights, specifically with the right to energy, [...]

by Zhichao Wang  , Daisuke Mori  , Sou Taminato  , Yasuo Takeda  , Osamu Yamamoto  and Nobuyuki Imanishi

Received: 28 April 2025;  Published: 13 August 2025;  doi: 10.21926/jept.2503011

Solid lithium-ion conducting polymer electrolytes are attractive candidates for battery applications because they are flexible and less flammable, and can be easily prepared as large-sized thin films. However, the room temperature conductivity of conventional polymer electrolytes is relatively low, and detrimental lithium dendrite formation is observed at high current density. In this study, a composite polymer electrolyte of polyethylene oxide (PEO) with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and a hi [...]

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, [...]

by Rafael B. Oliva  , Andrés Zappa  , Mariano Amadio  and Guillermo Catuogno

Received: 31 October 2024;  Published: 05 May 2025;  doi: 10.21926/jept.2502009

This work addresses the main results of a test site for small wind turbines (SWTs) located in Patagonia, and the development of the measurement systems involved, including the uncertainties calculations according to applicable IEC standards. Due to market evolution for over a decade, the test systems evolved from battery-charging SWTs to grid-connected units. The test site, developed and managed by state-owned INTI (National Institute for Industrial Technology), was established in 2012 and received support from the [...]