Grid-connected hybrid energy systems (GC-HES) require coordinated optimisation of economic, reliability, environmental and grid-operation objectives, yet published studies remain difficult to compare because system boundaries, objective definitions and statistical reporting are heterogeneous. We therefore applied a record-level data-integrity audit to the 73 bibliography-linked records preserved in the archived screening materials. Eligibility required a 2020–2025 English-language peer-reviewed journal article, an integrated system-level grid- or distribution-connected renewable-generation/storage architecture, explicit multi-objective or multi-criteria optimisation, and quantitative engineering outcomes. The record-level audit retained 17 primary studies and excluded 56 records: 26 secondary or methodological sources, 2 publications outside the protocol window, 3 conference or non-journal papers, 7 records for which grid-connected status was not demonstrated, 12 for which the multi-objective criterion was not demonstrated, and 6 outside the revised hybrid-system scope. Across the 17-study core, PV is represented in all studies, wind in 15, explicit storage in 12, economic or energy-import/loss objectives in 16, reliability or grid-performance objectives in 16, and explicit environmental or renewable-fraction objectives in 9. Nine studies provide direct within-study algorithm comparisons, but heterogeneous objectives, constraints, evaluation budgets and reporting prevent a defensible universal solver ranking. A pooled meta-analysis was not performed because harmonised, source-verifiable arm-level means, dispersion measures and statistical sample sizes were unavailable across the retained studies. The synthesis prioritises reproducible benchmarking, uncertainty-aware optimisation, explicit network constraints, degradation-aware storage, EV/V2G integration, digital twins and validated real-time energy management.
This study presents a combined enhancement approach to improve the thermal and electrical performance of a photovoltaic–thermal collector by utilizing a 50% TiO2–50% Fe3O4 hybrid nanofluid at 0.5% concentration and perforated twisted tape turbulators with different twist ratios. An experimental investigation was conducted to evaluate heat transfer effectiveness, energy efficiency, exergy efficiency, and hydraulic performance. The results indicate that a twist ratio of the two provides the best overall performance, achieving a heat transfer enhancement exceeding 67% compared to the baseline system. Maximum energy and exergy efficiencies of 82% and 30%, respectively, were obtained. These improvements are attributed to enhanced thermal conductivity and intensified fluid mixing. Although the proposed method increases pressure drop, the overall thermo-hydraulic performance remains favorable, as confirmed by the performance evaluation criterion. The findings demonstrate that the proposed configuration is an effective and practical solution for advanced photovoltaic–thermal applications.
Photovoltaic (PV) panel performance and efficiency are significantly affected by environmental conditions, such as elevated temperatures and dust accumulation, especially in hot, arid regions. These factors directly reduce energy output and limit system reliability, making their mitigation essential for sustainable PV operation. Generally, a 10°C rise in panel temperature causes a 5
The study assessed rare earth element (REE) pollution in Rawanduz River stream sediments in Iraq's Kurdistan Region. Twenty-seven stream sediment samples (> 80 mesh) were analyzed using Inductively Coupled Plasma Mass Spectrometry. Overall, REE concentrations were comparable to the Upper Continental Crust values, with light REE (LREE) dominating over middle and heavy REE, reflecting natural geological sources. Spatial patterns showed LREE enrichment with weak Eu and Ce anomalies in carbonate-dominated areas, while MREE enrichment and stronger anomalies occurred in zones possibly influenced by igneous and metamorphic lithologies, suggesting fractionation and sorting effects through weathering and hydrodynamic sorting. Geo-accumulation indices classified most sediments as unpolluted, with minor low-level enrichment in specific REE at certain districts. Factor analysis identified four main factors explaining 81.8
Investigation on thermal performance of nanofluid flat-plate solar collector in the severe hot climate. The investigation for experimentally test and numerical modeling is done with Baghdad, Iraq as a representative case. Three working fluids at 1 vol.
