References
management software. Screening: Titles and abstracts were screened for relevance to stand-alone PV performance and optimization. Irrelevant studies were excluded at this stage. Eligibility: Full-text articles were assessed against the inclusion and exclusion criteria. Studies lacking clear performance metrics or optimization frameworks were excluded. Inclusion: Only studies meeting all eligibility criteria were included in the final qualitative synthesis. Figure 1: Study selection Process (PRISMA phases) Data Extraction Eligible studies were subjected to a structured data-extraction procedure using a predefined extraction matrix. Extracted variables included: Author(s) and year, Study location, Type of PV system (stand-alone, hybrid, DC/AC coupled), Optimization strategy evaluated (e.g., cleaning technique, MPPT algorithm, array tilt optimization), Methodological approach (experimental, simulation, field measurement, techno-economic modelling), Key performance metrics (performance ratio, efficiency, energy yield, battery cycle life), Major findings and recommendations and Relevance to stand-alone PV systems in arid/semi-arid climates. Each study was scored as high-quality, moderate-quality, or low-quality based on the presence of methodological robustness and completeness of reported data. Low-quality or poorly documented studies were excluded to enhance the reliability of the final synthesis (Snyder, 2019). Data Synthesis Approach (Narrative + Comparative Tables) The final stage of the methodology employed a combined narrative and tabular synthesis approach to consolidate evidence across diverse study types. Narrative synthesis allowed thematic integration of findings on optimization techniques such as dust mitigation, MPPT strategies, and battery management. Comparative tables were used to present structured summaries of included studies by listing key parameters such as optimization method, study location, performance metric improvements, environmental conditions, and system configuration. This dual approach enhances clarity, supports cross-study comparisons, and enables identification of patterns, contradictions, and gaps in the literature (Page et al., 2021; Raza et al., 2022). Results and Discussion Overview of Stand-Alone Solar PV Systems Stand-alone solar photovoltaic (PV) systems have increasingly been recognized as viable solutions for providing reliable and cost-effective electricity in off-grid and rural contexts. Simulation-based studies indicate that hybrid optimization strategies, which integrate load assessment, solar resource analysis, and numerical system modeling, significantly enhance energy autonomy while minimizing excess energy losses, resulting in more stable and cost-effective PV designs (Abed et al., 2025). Reviews of global PV deployment further emphasize rapid technological advancements, including bifacial and perovskite cells, alongside challenges such as cost reduction and grid integration. These reviews highlight the critical need for policy support, infrastructure modernization, and sustained investment in innovative technologies (Ahmed et al., 2025). In Nigeria, the adoption of PV systems is shaped by multiple drivers and barriers. Falling PV costs and energy deficits are identified as key facilitators of adoption, while policy inconsistency, financing constraints, and inadequate infrastructure hinder large-scale deployment (Akinola, 2023). Moreover, affordability remains a significant challenge at the household level, with many families unable to finance PV systems despite declining global prices, indicating the need for targeted subsidies, micro-financing mechanisms, and local manufacturing initiatives (Diemuodeke et al., 2021). Techno-economic modeling studies further confirm that optimized PV system configurations are both technically feasible and economically attractive. For instance, standalone PV systems can provide stable electricity supply for residential estates and rural communities, offering reduced lifetime costs compared to diesel alternatives (Ayik et al., 2024; Ohajianya, 2023). Technical performance of PV systems is heavily influenced by environmental factors, particularly solar irradiance. Empirical studies show that PV output is highly sensitive to fluctuations in irradiance, especially during cloudy or rainy periods, highlighting the importance of accurate forecasting for system reliability (Omoriare et al., 2025). In addition, regional solar resource assessments using satellite imagery provide valuable insights for planning and optimizing system deployment. In Northern Nigeria, high annual solar potential (>5–6 kWh/m2/day) has been identified, enabling the selection of high-potential sites for PV development (Salihu et al., 2024). Similarly, urban residential areas in Abuja have been shown to benefit from optimized PV configurations, which reduce energy costs and improve electricity supply reliability (I.J. Renewable Energy Research, 2023). Overall, the literature demonstrates that well-designed stand- alone PV systems, supported by hybrid optimization techniques, accurate solar resource assessment, and enabling policy frameworks, can provide reliable, sustainable, and cost-effective electricity solutions. These systems are adaptable to diverse geographic and socio-economic contexts and hold significant potential for addressing energy access gaps in both rural and urban areas. Table 1: Overview of Stand-Alone Solar PV Systems Author Location/Stu dy Area Title of Paper Method Key Findings Conclusion Abed et al. (2025) Global (simulation- based design) Optimal sizing and performance assessment of stand-alone PV systems using optimum hybrid sizing strategy Hybrid optimization approach combining load assessment, solar resource analysis, and system simulation using numerical modeling. Optimal sizing significantly improves energy autonomy and reduces excess energy losses; hybrid strategy improves reliability of standalone PV systems. Hybrid optimization methods provide more stable and cost- effective standalone PV system designs. Ahmed et al. (2025) Global A Comprehensive Review of Solar Photovoltaic Systems: Scope, Technologies, Applications, Progress, Challenges, and Recommendati ons Systematic literature review across multiple PV technologies, applications, and global deployment trends. Identified rapid global PV technologica l growth; highlighted cost reduction, integration challenges, and emerging innovations such as bifacial and perovskite cells. PV development requires policy support, grid modernizatio n, and sustained investment in innovative technologies. Akinola (2023) Nigeria Solar Photovoltaics Development in Nigeria: Drivers, Policy and market analysis using secondary data from national energy Identified major drivers (energy deficit, Nigeria can accelerate PV adoption through stable policy Barriers, and Policies reports and case studies. falling PV costs) and barriers (policy inconsistenc y, financing constraints, poor infrastructur e). reforms and targeted incentives. Ayik et al. (2024) South Sudan Techno- Economic Modeling of Stand-Alone Solar Photovoltaic Systems: A Case Scenario from South Sudan Techno- economic modeling with HOMER software and local energy load assessment. Standalone PV systems are economicall y viable with reduced lifetime cost compared to diesel systems. Solar PV provides a cost- effective energy alternative for rural communities in South Sudan. Bisu et al. (2024) Northern Nigeria A SWOT Analysis Approach for the Development of Photovoltaic (PV) Energy in Northern Nigeria SWOT (Strengths– Weaknesses– Opportunities– Threats) framework based on regional energy datasets. Identified high solar irradiance and available land as strengths; infrastructur al limitations and vandalism as threats. Effective PV expansion requires security improvemen ts, investment support, and infrastructur e upgrades. Diemuode ke et al. (2021) Nigeria Solar PV Electrification in Nigeria: Cur
