Said Benkachcha^1,*, Mustapha Adar¹, Mohamed Maniana², Youssef Najih¹, Mourad Kaddiri¹, Mutapha Mabrouki¹

Energy Engineering, Vol.123, No.6, 2026, DOI:10.32604/ee.2026.075406 - 27 May 2026

Abstract Accurate forecasting of solar photovoltaic (PV) power generation is essential for enabling reliable integration of renewable energy into modern power systems. Variability in solar production, driven by meteorological fluctuations and inherent nonlinear dynamics, presents significant challenges for grid stability, operational planning, and energy management. This study investigates and compares the performance of classical statistical forecasting techniques and advanced deep learning approaches using real PV production data from a Moroccan solar plant. The analysis focuses on accuracy, robustness, computational efficiency, and suitability for short-term operational applications. Among statistical approaches, the Holt–Winters model demonstrated strong capability in… More > Graphic Abstract

Qingguo Nie, Yongfang Nie^*

Energy Engineering, Vol.123, No.6, 2026, DOI:10.32604/ee.2026.069025 - 27 May 2026

Abstract This study proposes an optimized design method for wind-solar-storage microgrid systems in the Gobi Desert region of northwest China. The core innovation is the development of a Modified Dragonfly Algorithm (MDA) to address the challenges of optimal system sizing and operation under complex desert conditions characterized by high renewable volatility and demanding environmental constraints. To strengthen the algorithm’s global search capability and convergence speed, three key enhancements are introduced: optimal point set initialization for even population distribution, cosine similarity guidance for balanced exploration-exploitation, and a nonlinear convergence factor for adaptive adjustment. The multi-objective optimization model… More >

Lanyue Liu¹, Chunzhi Zhang^1,*, Zhongyi Yu²

Energy Engineering, Vol.123, No.5, 2026, DOI:10.32604/ee.2025.071463 - 27 April 2026

Abstract This study develops an optimized integrated system for full-capacity hot water supply in hotels by combining solar thermal energy and air-source heat pumps. Using a hotel in Wuhan as a case study, a four-season × four-occupancy multidimensional working-condition matrix was established. Dynamic simulation and multi-objective optimization were performed on TRNSYS-TRNOPT, with the cost-benefit ratio (CBR) as the core evaluation metric. Key parameters—including collector area, tilt and azimuth angles, heat pump capacity, and storage tank volume—were jointly optimized. Model calibration against measured data yielded a deviation of less than 8%. The results demonstrate that the optimized More >

Yang Liu¹, Yinguo Yang¹, Pingping Xie¹, Qiuyu Lu¹, Yue Chen¹, Zhanpeng Xu^2,*, Zejie Huang²

Energy Engineering, Vol.123, No.5, 2026, DOI:10.32604/ee.2025.068436 - 27 April 2026

Abstract With the large-scale integration of wind and solar energy into the power grid, the power system is facing uncertainty challenges in multiple links, such as source, grid, and load. How to efficiently dispatch flexible resources, such as energy storage, has become an urgent problem to be solved. To this end, this paper considers the correlation between new energy stations due to natural conditions, uses Vine-Copula theory to describe the correlation characteristics of the output of multiple new energy stations, and proposes a wind solar new energy output scenario generation method based on Vine-Copula theory; Then,… More >

Ebtehal Chasseb Jbary^*, Alaa R. Al-Badri

Energy Engineering, Vol.123, No.3, 2026, DOI:10.32604/ee.2025.074415 - 27 February 2026

Abstract Despite significant advancements in solar collector technology, persistent challenges remain in improving the overall efficiency of solar systems. This paper investigates the use of mini-channel aluminum tubes mounted on the reflective surface as preliminary heating stages to enhance the overall system thermal performance. Experimental assessments were conducted with flow rates ranging from 0.1 to 0.8 LPM and tilt angles of 180° South and 225° Southwest in Al-Kut, Iraq, from 9:00 AM to 2:00 PM. Fluid flows sequentially through five flat aluminum tubes totaling 50 channels, named stage-1, then flows through four aluminum tubes totaling 40… More >

Firas Mahmood Younis^1,*, Omar Mohammad Hamdoon², Ayad Younis Abdulla¹

Energy Engineering, Vol.123, No.2, 2026, DOI:10.32604/ee.2025.073483 - 27 January 2026

Abstract This paper presents an experimental analysis of a solar-assisted powered underfloor heating system, designed primarily to boost energy efficiency and achieve reliable desired steady-state temperature in buildings. We thoroughly tested the system’s thermal and operational features by subjecting it to three distinct scenarios that mimicked diverse solar irradiance and environmental conditions. Our findings reveal a strong correlation between variations in solar input and overall system performance. The Solar Fraction (SF), our key energy efficiency metric, varied significantly across the cases, ranging from 63.1% up to 88.7%. This high reliance on renewables resulted in a substantial… More >

Sarah M. Alhammad¹, Diaa Salama AbdElminaam^2,3,*, Asmaa Rizk Ibrahim⁴, Ahmed Taha²

CMC-Computers, Materials & Continua, Vol.86, No.3, 2026, DOI:10.32604/cmc.2025.069263 - 12 January 2026

Abstract Accurate parameter extraction of photovoltaic (PV) models plays a critical role in enabling precise performance prediction, optimal system sizing, and effective operational control under diverse environmental conditions. While a wide range of metaheuristic optimisation techniques have been applied to this problem, many existing methods are hindered by slow convergence rates, susceptibility to premature stagnation, and reduced accuracy when applied to complex multi-diode PV configurations. These limitations can lead to suboptimal modelling, reducing the efficiency of PV system design and operation. In this work, we propose an enhanced hybrid optimisation approach, the modified Spider Wasp Optimization… More >

S. H. Fan^1,*, Y. S. Song¹, H. J. Hou¹, H. L. Guo², S. R. Zhang³

Chalcogenide Letters, Vol.22, No.12, pp. 987-997, 2025, DOI:10.15251/CL.2025.2212.987 - 01 December 2025

Abstract Using first-principles calculations, the physical behavior of α-Cu₂Se are thoroughly examined. The computed structural parameters align closely with experimental data. Through computational analysis, the electronic properties for α-Cu₂Se are determined. Additionally, mechanical characteristics-including bulk modulus B, shear modulus G, Young’s modulus E, and B/G are evaluated under varying pressure conditions. Furthermore, the optical properties are investigated. The study reveals that α-Cu₂Se exhibits a direct bandgap of 0.782 eV, indicating its promising potential for optoelectronic applications. More >

Mussad Mohammed Al-Zahrani^*, Taher Maatallah

Frontiers in Heat and Mass Transfer, Vol.23, No.6, pp. 1883-1905, 2025, DOI:10.32604/fhmt.2025.074656 - 31 December 2025

Abstract Conventional concentrator photovoltaics (CPV) face a persistent trade-off between high efficiency and high cost, driven by expensive multi-junction solar cells and complex active cooling systems. This study presents a computational investigation of a novel Multi-Focal Pyramidal Array (MFPA)-based CPV system designed to overcome this limitation. The MFPA architecture employs a geometrically optimized pyramidal concentrator to distribute concentrated sunlight onto strategically placed, low-cost monocrystalline silicon cells, enabling high efficiency energy capture while passively managing thermal loads. Coupled optical thermal electrical simulations in COMSOL Multiphysics demonstrate a geometric concentration ratio of 120×, with system temperatures maintained below More >

Jinyou Qiu^1,2, Jiale Liu^1,2, Yubing Li^1,2,*, Shaogeng Zhong³, Guilong Dai^1,2, Wenhua Liu⁴

Frontiers in Heat and Mass Transfer, Vol.23, No.6, pp. 2025-2049, 2025, DOI:10.32604/fhmt.2025.072260 - 31 December 2025

Abstract The growing demand for energy-saving and renewable heating solutions has made photovoltaic/thermal (PV/T) heat pump systems a promising technology. However, their thermal and electrical performance, as well as the overall utilization of solar energy, strongly depend on capacity configuration and operating parameters. To address this issue, this study proposes a PV/T heat pump system featuring a novel rhombic flow channel structure that functions as the collector-evaporator. An experimental test bench was established to evaluate system performance, and a one-dimensional numerical model was developed to investigate the effects of environmental and operating parameters. The simulation results… More > Graphic Abstract