by Kuok Ho Daniel Tang

Received: 04 February 2026;  Published: 22 June 2026;  doi: 10.21926/jept.2602011

Bioenergy plays a differentiated yet increasingly strategic role in national energy transitions, shaped by distinct policy architectures, market structures, and developmental priorities. This review compares the bioenergy policies and markets of China, the United States (US), and India, three of the world’s largest energy consumers, to assess their implications for global bioenergy transitions. China’s bioenergy sector is embedded within a centralized, planning-based governance framework, emphasizing waste-to-energ [...]

by Dudu Mertgenç Yoldaş  , Senai Yalçinkaya  and Mehmet Fatih Yoldaş

Received: 13 January 2026;  Published: 03 June 2026;  doi: 10.21926/jept.2602010

The increasing demand for sustainable energy has accelerated the development of high-performance wind turbine systems. In this context, material selection for turbine blades plays a critical role in ensuring structural efficiency, fatigue resistance, and long-term reliability. This study evaluates the mechanical and structural advantages of carbon fiber-reinforced polymer (CFRP) composites over glass fiber-reinforced polymer (GFRP) materials in wind turbine blade applications. Results from the literature indicate t [...]

by Peter Ebhodaghe Akhator  and Ufuoma Georgina Unueroh

Received: 16 February 2026;  Published: 15 May 2026;  doi: 10.21926/jept.2602009

Waste-derived briquettes offer a promising alternative to fossil fuels and are characterised by low production costs, high volumetric calorific value, robust mechanical strength, and excellent durability. To optimize their adoption, four variants of waste-derived briquettes were produced with different mass ratios of sawdust to polyethylene terephthalate (PET) plastic (100:0, 90:10, 80:20, and 70:30) using high-pressure compaction without binders. Thermogravimetric analysis (TGA) and the Coats-Redfern method were e [...]

by G.-Fivos Sargentis  , Nikolaos Papadodimas  , Ioannis Benekos  , Nikolaos M. Katsoulakos  , Panayiotis Dimitriadis  , Nikos Tepetidis  , Romanos Ioannidis  , Ilias Arvanitidis  , Marios Athanasios Angelidis  , Danai Saperopoulou  , Georgios David Laoutaris  , Matthaios Maravelakis  , Orestis I. Amiralis  , David Markantonis  , Athanasia Alexandridou  , Nikos Mamassis  and Demetris Koutsoyiannis

Received: 20 December 2025;  Published: 20 April 2026;  doi: 10.21926/jept.2602008

The increasing penetration of renewable energy sources (RES) in the energy mix, particularly solar photovoltaic and wind power, poses significant challenges to electricity grid reliability due to their inherent stochastic variability. This study develops a stochastic framework to assess the ability of RES to balance electricity demand, with a focus on storage requirements and reliability implications. Using North Euboea, Greece, as a representative case study, normalized hourly time series of electricity demand, so [...]

by Leonardo Alves Messias  , José Luis Domingos  , Thiago Augusto Mendes  , Bruno Barzellay Ferreira da Costa  , Ana Carolina Fernandes Maciel  , Saymon Fonseca Santos Mendes  and Raphael de Aquino Gomes

Received: 17 October 2025;  Published: 03 April 2026;  doi: 10.21926/jept.2602007

The increasing demand for renewable energy sources has intensified the adoption of photovoltaic systems. This study proposes predictive models for solar power generation that operate without dependence on on-site meteorological stations. The proposed approach integrates generation data from geographically distributed plants and accounts for the distance to meteorological stations when constructing climatic variables. Two machine learning techniques, Random Forest (RF) and Long Short-Term Memory (LSTM) networks, wer [...]

by Walid Mohamed Mahmud

Received: 09 September 2024;  Published: 26 March 2026;  doi: 10.21926/jept.2601006

Electrical submersible pumps (ESPs) are an efficient and reliable artificial lift method for lifting large volumes of fluids from wellbores at flexible rates. Despite their advantages, including high flow rates and real-time downhole telemetry, ESPs are prone to frequent and unforeseen failures under harsh reservoir conditions, resulting in costly production delays and interventions. This paper presents an integrated evaluation of ESP failure mechanisms based on an analysis of run and pull reports, dismantle inspec [...]

by Brendan Ifeany Ekwueme  , Ogheneruona Endurance Diemuodeke  , Mohammed Moore Ojapah  and Chidozie Ezekwem

Received: 17 September 2025;  Published: 09 March 2026;  doi: 10.21926/jept.2601005

The work focused on modelling and optimisation of integrated renewable energy conversion technologies based on sunlight, wind, and biomass, with dual energy storage (battery and hydrogen), for Patani Island, Delta State, Nigeria. The study was aimed at satisfying the energy demand of the Patani Island community (5°13’43” N, 6°11’29” E). A mathematical model was developed to describe the integrated system, and a genetic algorithm was employed to optimize the allocation of energy demand, energy generation, and energy [...]

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

Received: 18 November 2025;  Published: 26 February 2026;  doi: 10.21926/jept.2601004

A thin film of PEO18Li(CF3SO2)2N(LiTFSI)-tetraethylene glycol dimethyl ether (G4)-Li1.4Al0.4Ge0.2Ti1.4(PO4)3-LiCl·H2O (LAGTP·LiCl) was prepared by addition of 1,2-dimethoxyethane (DME). The grain boundary resistance of PEO18LiTFSI-LAGTP·LiCl was considerably reduced by the addition of G4, and a large-sized thin film of the composite polymer electrolyte was prepared easily by the addition of 10 wt.% DME. The electrical conductivity of [(PEO18LiTFSI-2G4)-5 wt.% LAGTP·LiCl]-10 wt.% DME was 1.2 × 10-4 S cm-1 at 25°C, a [...]

by Emeka H. Amalu  and Justice O. Nwaneto

Received: 26 June 2025;  Published: 13 February 2026;  doi: 10.21926/jept.2601003

As the demand for cleaner-greener energy surges owing to more nations adopting Net Zero Emission by 2050, wind turbine (WT) technology is increasingly poised as one of the technologies to match the demand. Capacity building in the development of cost-effective WT tower with improved reliability and safety has become critical to delivering Net Zero mandate. This research demonstrates implementation of Taguchi Design of Experiment (DoE) in conjunction with Signal-to-noise ratio (S/N) to optimise both structural desig [...]

by Uchechukwu Nwaiwu  , Fan He  , Matthew Leach  and Lirong Liu

Received: 31 July 2025;  Published: 12 January 2026;  doi: 10.21926/jept.2601002

Increasing local energy access in developing countries, particularly in off-grid regions where mini-grids are often overloaded, remains a critically underexplored area in energy transition. These regions often face significant technical and economic challenges, such as low generation capacity, high energy costs, limited energy access, and heavy reliance on diesel fuels. This study explores capacity expansion by integrating small-scale geothermal energy into such a mini-grid system to enhance the local energy supply [...]