Hybrid Electrical Grounding Material for Saline Environments: A Systematic Review and Meta-Analysis of Multi-Objective Optimisation Considering Soil Salinity and Life-Cycle Cost

Abstract

Electrical grounding systems are critical for personnel safety, equipment protection, and power grid stability. Conventional materials, primarily copper, galvanised steel, and other bare copper conductors, are susceptible to accelerated corrosion in aggressive soils, particularly in saline and tropical environments, leading to performance degradation and increased life-cycle costs. Over the past decade (2015–2025), hybrid grounding materials integrating conductive metals, carbon-based nanocomposites, and engineered cementitious backfills have emerged as promising alternatives. Their design is increasingly tuned using multi-objective evolutionary algorithms to navigate safety, durability, and economic constraints. This systematic review synthesises global evidence on optimising hybrid grounding systems, explicitly framing soil salinity as a mediating factor and Life-Cycle Cost (LCC) as a moderator of safety-performance trade-offs. Adhering to the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) 2020 guidelines, 24 peer-reviewed articles from 2015 to 2025 were identified through structured searches of IEEE Xplore, ScienceDirect, SpringerLink, MDPI, and Google Scholar. 24 studies met the inclusion criteria and formed the core corpus for quantitative meta-analysis. An additional 20 references comprising IEEE standards, methodological guidelines, foundational works, and supporting studies are cited for context. Thematic synthesis revealed five core domains: (1) hybrid material innovations, (2) salinity-corrosion-resistivity coupling, (3) algorithmic optimisation, (4) LCC integration, and (5) empirical validation gaps. A proxy-based meta-analysis of 16 studies, using the Lakens heuristic (SMD ≈ % reduction/43) to transform percentage improvements into standardised mean differences, quantified performance, indicating that hybrid systems can reduce grounding resistance by 18%–42% and extend service life by 2.1–3.4 times under high-salinity conditions. However, fewer than 20% of studies dynamically incorporated LCC into optimisation frameworks, and none validated designs in West African or Ghanaian soil ecosystems. The critical methodological gap identified is the lack of field-calibrated, salinity-responsive optimisation models suitable for tropical environments. This review concludes by proposing a unified research framework that integrates COMSOL/MATLAB multi-physics simulations, Sobol indices for global sensitivity analysis, and in situ validation in Ghana, and by posing specific research questions to guide future investigation. This approach aims to bridge the simulation-field divide and contribute to the development of contextually grounded earthing standards. This study contributes a novel mediation moderation framework and provides a pathway toward developing context-specific grounding standards for tropical environments.