Fadhil M. Oleiwi¹, Jaber O. Dahloos², Amer Resen Kalash³, Hasanain A. Abdul Wahhab³, Miqdam T. Chaichan^1,4,*

Energy Engineering, Vol.123, No.2, 2026, DOI:10.32604/ee.2025.073313 - 27 January 2026

Abstract In the present study, researchers examined a solar off-grid-connected photovoltaic system for a family house in the city of Baghdad. The design was created with the help of the “How to Design PV Program” and the “Renewable Energy Investment Calculator (REICAL)” software (Version 1.1). In Iraq, the national grid provides around 71% of the overall electricity demand, though this drops to nearly 50% during extremely hot and cold months, where the supply alternates between four hours on and four hours off. During the off periods, power is generated by local generators at high costs. To… More >

Dexiecia Anak Francis¹, Jalal Tavalaei¹, Hadi Nabipour Afrouzi^2,*

Energy Engineering, Vol.123, No.2, 2026, DOI:10.32604/ee.2025.070501 - 27 January 2026

Abstract Wave energy is a promising form of marine renewable energy that offers a sustainable pathway for electricity generation in coastal regions. Despite Malaysia’s extensive coastline, the exploration of wave energy in Sarawak remains limited due to economic, technical, and environmental challenges that hinder its implementation. Compared to other renewable energy sources, wave energy is underutilized largely because of cost uncertainties and the lack of local performance data. This research aims to identify the most suitable coastal zone in Sarawak that achieves an optimal balance between energy potential, cost-effectiveness, and environmental impact, particularly in relation to… More >

Chenxuan Zhang, Yongqing Qi^*, Ximin Cao, Yanchi Zhang

Energy Engineering, Vol.123, No.2, 2026, DOI:10.32604/ee.2025.069878 - 27 January 2026

Abstract To enhance the low-carbon economic efficiency and increase the utilization of renewable energy within integrated energy systems (IES), this paper proposes a low-carbon dispatch model integrating power-to-gas (P2G), carbon capture and storage (CCS), hydrogen fuel cell (HFC), and combined heat and power (CHP). The P2G process is refined into a two-stage structure, and HFC is introduced to enhance hydrogen utilization. Together with CCS and CHP, these devices form a multi-energy conversion system coupling electricity, heat, cooling, and gas. A ladder-type carbon trading approach is adopted to flexibly manage carbon output by leveraging marginal cost adjustments.… More >

Miriam Di Matteo^*, Domiziana Vespasiano, Gianluigi Lo Basso, Costanza Vittoria Fiorini, Andrea Vallati

Energy Engineering, Vol.123, No.2, 2026, DOI:10.32604/ee.2025.064353 - 27 January 2026

Abstract Decarbonising the building sector, particularly residential heating, represents a critical challenge for achieving carbon-neutral energy systems. Efficient solutions must integrate both technological performance and renewable energy sources while considering operational constraints of existing systems. This study investigates a hybrid heating system combining a natural gas boiler (NGB) with an air-to-water heat pump (AWHP), evaluated through a combination of laboratory experiments and dynamic modelling. A prototype developed in the Electrical and Energy Engineering Laboratory enabled the characterization of both heat generators, the collection of experimental data, and the calibration of a MATLAB/Simulink model, including emissions and… More >

Marija Macenić, Tomislav Kurevija^*, Tin Herbst

Energy Engineering, Vol.123, No.1, 2026, DOI:10.32604/ee.2025.067067 - 27 December 2025

Abstract The increased interest in geothermal energy is evident, along with the exploitation of traditional hydrothermal systems, in the growing research and projects developing around the reuse of already-drilled oil, gas, and exploration wells. The Republic of Croatia has around 4000 wells, however, due to a long period since most of these wells were drilled and completed, there is uncertainty about how many are available for retrofitting as deep-borehole heat exchangers. Nevertheless, as hydrocarbon production decreases, it is expected that the number of wells available for the revitalization and exploitation of geothermal energy will increase. The… More >

Hao Yue¹, Di Gao², Jin Gao¹, Chengmei Wei¹, Jiali Duan³, Shaocheng Mei^3,*

Energy Engineering, Vol.122, No.12, pp. 5091-5109, 2025, DOI:10.32604/ee.2025.069140 - 27 November 2025

Abstract Against the backdrop of regional coordinated development and China’s “dual carbon” strategic objectives, the Beijing-Tianjin-Hebei (BTH) region faces an urgent need to transition from its traditional economic growth model, which is heavily reliant on resource consumption. This study investigates the decoupling dynamics among economic growth, energy consumption, and carbon emissions in the BTH region, along with the underlying driving forces, aiming to provide valuable insights for achieving the “dual carbon” targets and fostering high-quality regional development. First, the Tapio decoupling model is employed to analyze the decoupling relationships between economic growth, energy consumption, and carbon… More >

Leonid Plotnikov^1,*, Danil Davydov^1,2, Dmitry Krasilnikov^1,2, Alexander Ryzhkov²

Energy Engineering, Vol.122, No.11, pp. 4621-4633, 2025, DOI:10.32604/ee.2025.070713 - 27 October 2025

Abstract Improving the specific, technical, economic, and environmental characteristics of piston engines (ICE) operating on alternative gaseous fuels is a pressing task for the energy and mechanical engineering industries. The aim of the study was to optimize the parameters of the ICE working cycle after replacing the base fuel (propane-butane blend) with syngas from wood sawdust to improve its technical and economic performance based on mathematical modeling. The modeling results were verified through experimental studies (differences for key parameters did not exceed 4.0%). The object of the study was an electric generator based on a single-cylinder… More >

Jack Kiing Teck Wei¹, Mohanad Taher Mohamed Sayed Roshdy¹, Bryan Ho Liang Hui¹, Jalal Tavalaei¹, Hadi Nabipour Afrouzi^2,*

Energy Engineering, Vol.122, No.11, pp. 4755-4775, 2025, DOI:10.32604/ee.2025.069980 - 27 October 2025

Abstract In this article, a hybrid energy storage system powered by renewable energy sources is suggested, which is connected to a grid-tied electric vehicle charging bay (EVCB) in Sarawak and is examined for its techno-economic effects. With a focus on three renewable energy sources, namely hydrokinetic power, solar power, and hydrogen fuel cells, the study seeks to minimize reliance on the electrical grid while meeting the growing demand from the growing electric vehicle (EV) infrastructure. A hybrid renewable energy storage system that combines solar power, hydrogen fuel cells, hydrokinetic power, and the grid was simulated and… More >

Yukun Yang^*, Jun He, Wenfeng Chen, Zhi Li, Kun Chen

Energy Engineering, Vol.122, No.11, pp. 4653-4678, 2025, DOI:10.32604/ee.2025.068199 - 27 October 2025

Abstract To address the issues of unclear carbon responsibility attribution, insufficient renewable energy absorption, and simplistic carbon trading mechanisms in integrated energy systems, this paper proposes an electric-heat-hydrogen integrated energy system (EHH-IES) optimal scheduling model considering carbon emission stream (CES) and wind-solar accommodation. First, the CES theory is introduced to quantify the carbon emission intensity of each energy conversion device and transmission branch by defining carbon emission rate, branch carbon intensity, and node carbon potential, realizing accurate tracking of carbon flow in the process of multi-energy coupling. Second, a stepped carbon pricing mechanism is established to… More >

Khairul Eahsun Fahim¹, Liyanage C. De Silva², Sk. A. Shezan^3,*, Md Ashraful Islam⁴, Md Shakib Hassan⁵, Hayati Yassin^1,*, Naveed Ahmad⁶

Energy Engineering, Vol.122, No.10, pp. 3985-3997, 2025, DOI:10.32604/ee.2025.066484 - 30 September 2025

Abstract Around the world, there has been a notable shift toward the use of renewable energy technology due to the growing demand for energy and the ongoing depletion of conventional resources, such as fossil fuels. Following this worldwide trend, Brunei’s government has initiated several strategic programs aimed at encouraging the establishment of energy from renewable sources in the nation’s energy mix. These initiatives are designed not only to support environmental sustainability but also to make energy from renewable sources increasingly competitive in comparison to more conventional energy sources like gas and oil, which have historically dominated… More >