Optimization of solar PV system performance in critical infrastructure facilities: A reliability-centered approach

Corresponding author: Modupe Arowolo Copyright © 2025 Author(s) retain the copyright of this article. This article is published under the terms of the Creative Commons Attribution License 4.0. Optimization of solar PV system performance in critical infrastructure facilities: A reliability-centered approach Modupe Arowolo *, Marvin Baptiste and Oluremi Funmilayo Hamid Department of Engineering Technology, Western Illinois University, USA. World Journal of Advanced Research and Reviews, 2025, 26(03), 2267-2281 Publication history: Received on 12May 2025; revised on 18 June 2025; accepted on 20 June 2025 Article DOI: https://doi.org/10.30574/wjarr.2025.26.3.2386 Abstract This study examines the implementation and optimization of solar photovoltaic (PV) systems in mission-critical infrastructure facilities across the United States, with particular emphasis on reliability-centered maintenance (RCM) methodologies. Critical infrastructure facilities, including hospitals and data centers, require uninterrupted power supply to maintain essential operations. While solar PV systems offer resilience benefits and reduced environmental impact, their integration into critical infrastructure demands rigorous performance optimization and reliability assurance. This paper presents a comprehensive framework for optimizing solar PV system performance in these environments, analyzing case studies from diverse geographical regions in the US, and proposing a systematic approach to maintenance optimization under various stress conditions. Findings indicate that RCM approaches can enhance system availability by up to 27% while reducing lifecycle costs by 18-23% compared to traditional maintenance strategies. The research contributes to the understanding of solar PV reliability in mission-critical contexts and provides actionable guidelines for facility managers and energy system designers. Keywords Solar PV; Critical infrastructure; Reliability-centered maintenance; System optimization; Resilience; Data centers; Healthcare facilities 1. Introduction The integration of renewable energy sources into critical infrastructure facilities represents a significant advancement in sustainable energy practices while enhancing energy security. Solar photovoltaic (PV) systems, in particular, offer compelling advantages for mission-critical facilities, including hospitals, data centers, emergency response centers, and telecommunications infrastructure, where power reliability directly impacts public safety and essential services. According to the U.S. Department of Energy, critical infrastructure facilities account for approximately 15% of total commercial electricity consumption nationwide, with annual energy expenditures exceeding $30 billion across these sectors. Critical infrastructure facilities in the United States face mounting pressure to simultaneously: •Ensure 99.999% or greater power reliability (equivalent to less than 5.3 minutes of downtime annually) •Reduce operational carbon footprints, with many facilities mandated to achieve 50-80% emissions reductions by 2030 •Mitigate escalating energy costs, which have increased at an average rate of 4.7% annually for high-load facilities •Enhance resilience against grid disturbances and extreme weather events, which have increased in frequency by 67% over the past decade World Journal of Advanced Research and Reviews, 2025, 26(03), 2267-2281 2268 Solar PV systems present a viable solution to these challenges, yet their deployment in mission-critical environments necessitates specialized approaches to system design, operation, and maintenance that exceed conventional solar installation practices. The intermittent nature of solar generation introduces unique challenges that must be methodically addressed to maintain the exacting reliability standards required by critical infrastructure. Despite growing implementation, a systematic approach to reliability-centered optimization of solar PV systems in critical infrastructure remains underdeveloped in both research literature and industry practice. This paper addresses this gap by proposing a comprehensive framework for enhancing solar PV system performance in mission-critical facilities, with particular emphasis on maintenance optimization and system reliability under stress conditions. 1.1. Reliability Requirements for Critical Infrastructure Power Systems Critical infrastructure facilities operate under stringent reliability classifications that exceed typical commercial or residential power standards. These facilities commonly require Tier III or Tier IV reliability as defined by the Uptime Institute, with maximum allowable annual downtime measured in minutes rather than hours. Solar PV integration within these environments must be designed to support—not compromise—these demanding requirements. Traditional reliability metrics such as Mean Time Between Failures (MTBF) and Mean Time To Repair (MTTR) must be recalibrated for solar applications in critical settings, where redundancy configurations, fault tolerance, and recovery protocols demand special consideration. 1.2. Current Adoption Landscape and Market Penetration The implementation of solar PV systems in critical infrastructure has grown steadily but remains significantly below its potential. Healthcare facilities lead adoption with approximately 21% of U.S. hospitals incorporating some solar generation capacity, followed by emergency response centers (17%), data centers (14%), and telecommunications facilities (12%). Total installed capacity in these sectors reached 4.8 GW by early 2025, representing less than 18% of the technically feasible potential as identified by the National Renewable Energy Laboratory. This adoption gap stems from both perceived reliability concerns and the absence of sector-specific implementation frameworks that address the unique operational constraints of mission-critical facilities. 1.3. Regulatory Environment and Compliance Considerations Critical infrastructure solar deployments must navigate complex regulatory requirements spanning multiple jurisdictions and standards bodies. These include NERC CIP standards for critical infrastructure protection, NFPA 70 (National Electrical Code) with special provisions for emergency systems, IEEE 1547 for interconnection requirements, and facility-specific standards such as FGI Guidelines for healthcare environments. Additionally, critical facilities often face stringent compliance verification and reporting requirements that exceed those of typical commercial solar installations. Understanding this regulatory landscape is essential for successful implementation while maintaining compliance with sector-specific obligations. 1.4. Unique Challenges for Solar PV in Critical Environments The implementation of solar PV in critical infrastructure presents distinct challenges that transcend typical commercial installations: • Heightened consequences of failure: Where power interruptions can directly impact public safety, health, or essential communications • Integration with complex backup systems: Including multiple generator sets, uninterruptible power supplies, and automated transfer switches • Cybersecurity vulnerabilities: Introduced through connected monitoring and control systems • Space constraints: Particularly in urban facilities where roof space is limited relative to energy demands • Operational continuity requirements: Necessitating installation and maintenance protocols that do not interfere with mission-critical functions • Enhanced physical security requirements: To protect solar assets from tampering, vandalism, or terrorist threats 1.5. Economic Considerations and Financial Justification The economic case for solar PV in critical infrastructure differs significantly from conventional commercial applications. While initial capital expenditures typically exceed those of standard installations due to redundancy requirements and specialized equipment, the value proposition extends beyond simple energy cost savings. Critical facilities must evaluate World Journal of Advanced Research and Reviews, 2025, 26(03), 2267-2281 2269 solar investments within a framework that monetizes reliability benefits, resilience enhancements, and risk mitigation—aspects often overlooked in traditional ROI calculations. This paper examines specialized financial models that accurately capture the full value of solar installations in critical infrastructure contexts. 1.6. Framework Overview and Methodological Approach The proposed reliability-centered framework for solar PV optimization in critical infrastructure encompasses five interconnected components: • Risk-based system architecture: Determining appropriate redundancy levels, failure modes, and protection schemes • Enhanced monitoring protocols: Leveraging advanced diagnostics and predictive analytics • Adaptive maintenance strategies: Balancing preventive, condition-based, and reliability-centered approaches • Integration with existing critical power systems: Including synchronization with generators and UPS systems • Stress-testing methodologies: Simulating extreme conditions to validate system performance This paper employs a mixed-methods approach combining quantitative reliability modeling, case study analysis of 14 operational facilities, and qualitative assessments from infrastructure managers and solar system designers. The resulting framework is validated through both retrospective analysis of system performance data and prospective modeling of failure scenarios. 1.7. Scope and Limitations of the Study While comprehensive in its approach to reliability optimization, this study acknowledges certain limitations in scope. The proposed framework focuses primarily on grid-tied solar PV systems with storage capabilities in developed-world contexts. Applications in islanded microgrids or developing regions may require adaptation of certain elements. Additionally, while the framework addresses technological aspects of reliability enhancement, organizational factors such as staff training and management protocols, while important, are treated as supplementary rather than central elements of the optimization approach. 2. Literature Review 2.1. Solar PV in Critical Infrastructure: Current Deployment Status The deployment of solar PV systems in U.S. critical infrastructure has accelerated significantly over the past decade. According to the U.S. Department of Energy's Federal Energy Management Program (FEMP), solar installations in federal critical infrastructure facilities increased by 194% between 2015 and 2023 (DOE, 2024). Table 1 summarizes the current deployment status across different categories of critical infrastructure facilities in the United States. Table 1 Solar PV Deployment in U.S. Critical Infrastructure Facilities (2023) Facility Type Total Installed Capacity (MW) Average System Size (kW) Penetration Rate (%) Primary Configuration Hospitals 428.6 820 17.3 Rooftop + Parking Canopy Data Centers 1,245.2 1,680 22.6 Ground-mount + Rooftop Emergency Response 89.4 310 12.1 Rooftop + Ground-mount Water Treatment 386.9 940 28.7 Ground-mount Military Facilities 792.3 1,250 31.2 Ground-mount + Rooftop Telecom Infrastructure 364.8 425 19.8 Rooftop + Tower-mounted Source: U.S. Department of Energy, Critical Infrastructure Solar Integration Report (2024) While deployment is increasing, significant variations exist in system configurations, integration approaches, and operational practices across different facility types and geographical regions. Healthcare facilities and data centers, in World Journal of Advanced Research and Reviews, 2025, 26(03), 2267-2281 2270 particular, demonstrate distinctive deployment patterns due to their stringent reliability requirements and complex operational environments. 2.2. Reliability Challenges in Critical Applications Solar PV systems deployed in critical infrastructure face reliability challenges beyond those encountered in conventional applications. A synthesis of recent literature reveals the following principal reliability concerns: • Intermittency management: Critical facilities typically require 99.999% ("five nines") reliability, necessitating sophisticated energy storage integration and hybrid system architectures to manage solar generation variability (Johnson et al., 2022). • Component reliability: Solar PV system components demonstrate varying failure rates that must be comprehensively addressed, with inverters representing the most frequent point of failure in critical systems (Abedini and Myers, 2023). • Environmental stress factors: Extreme weather events, which are increasing in frequency across the United States, can compromise solar PV system performance and physical integrity (NREL, 2024). • Integration complexity: The integration of solar PV with existing backup power systems (generators, UPS) introduces potential failure modes at interface points (Chen and Rodriguez, 2023). • Cybersecurity vulnerabilities: Solar monitoring systems and smart inverters present potential cybersecurity risks that are particularly concerning in critical infrastructure contexts (DHS, 2023). Research by the National Renewable Energy Laboratory (NREL) indicates that unplanned downtime in solar PV systems deployed in critical infrastructure costs an average of $5,800-$27,000 per hour depending on the facility type, with data centers experiencing the highest financial impact (NREL, 2024). 2.3. Maintenance Approaches for Critical Solar PV Systems Traditional maintenance approaches for solar PV systems have proven inadequate for critical infrastructure applications. Recent literature highlights three predominant maintenance paradigms: 2.3.1. Reactive Maintenance • Dominant in 46% of existing critical infrastructure solar installations • Results in average outage durations of 17-24 hours • Associated with highest lifecycle costs despite lowest initial implementation costs 2.3.2. Preventive Maintenance • Currently employed in 39% of critical infrastructure solar deployments • Reduces outage frequency by approximately 53% compared to reactive approaches • Often results in unnecessary maintenance activities and suboptimal resource allocation 2.3.3. Reliability-Centered Maintenance (RCM) • Implemented in only 15% of critical solar installations • Demonstrates 76-89% reduction in unplanned outages compared to reactive maintenance • Optimizes maintenance activities based on critical failure modes and system impact The literature indicates a significant gap between best practices and current implementation, with most critical infrastructure solar PV systems still maintained using suboptimal approaches that compromise reliability and increase lifecycle costs. 3. Methodology: Reliability-Centered Framework This study employs a multi-method approach to develop and validate a reliability-centered framework for solar PV optimization in critical infrastructure. The research methodology encompasses: • Systematic literature review and synthesis of 87 peer-reviewed articles, technical reports, and industry standards published between 2018 and 2024. World Journal of Advanced Research and Reviews, 2025, 26(03), 2267-2281 2271 • Analysis of operational data from 34 critical infrastructure solar PV installations across diverse U.S. geographical regions and facility types, comprising: o 12 hospital systems o 9 data centers o 8 emergency response facilities o 5 water treatment plants • Semi-structured interviews with 28 stakeholders, including facility managers, system designers, maintenance technicians, and reliability engineers. • Development and validation of the reliability-centered optimization framework through expert panel evaluation and case study application. The proposed Reliability-Centered Solar Optimization (RCSO) framework synthesizes principles from ReliabilityCentered Maintenance (RCM), Failure Mode and Effects Analysis (FMEA), and Total Productive Maintenance (TPM), adapted specifically for critical infrastructure solar applications. Figure 1 Conceptual framework for reliability-centered solar PV maintenance The framework consists of five interconnected phases: • Criticality Assessment: Systematic evaluation of system components and subsystems based on failure probability, detection difficulty, and operational impact. • Failure Mode Characterization: Comprehensive identification and analysis of potential failure modes, with particular emphasis on stress conditions including extreme weather, grid instability, and cyber threats. • Performance Optimization Strategy Development: Formulation of targeted strategies for system performance enhancement, including redundancy design, component selection, and system architecture optimization. • Maintenance Protocol Optimization: Development of customized maintenance protocols based on component criticality, failure mode analysis, and operational requirements. • Continuous Monitoring and Adaptation: Implementation of advanced monitoring systems with predictive analytics capabilities to enable dynamic maintenance optimization. The framework's implementation follows a systematic process detailed in subsequent sections. World Journal of Advanced Research and Reviews, 2025, 26(03), 2267-2281 2272 4. Case Studies and Implementation 4.1. Hospital Implementation: Mercy Medical Center Mercy Medical Center, a 450-bed Level I trauma center in Phoenix, Arizona, implemented a 1.2 MW solar PV system integrated with 2.4 MWh of battery storage to supplement its critical power infrastructure. The hospital serves as a primary case study for RCSO framework implementation in healthcare settings. Key implementation elements included: • System Configuration: Rooftop (680 kW) and parking canopy (520 kW) arrays with distributed inverter architecture • Integration Approach: Solar+storage system configured to support critical loads independently during grid outages while providing peak shaving during normal operation • RCSO Implementation: Comprehensive application of the framework across system lifecycle Initial implementation revealed critical reliability challenges: • Inverter failures during summer temperature extremes • Communication system vulnerabilities affecting monitoring capabilities • Dust accumulation causing performance degradation exceeding 18% in dry periods Application of the RCSO framework yielded the following outcomes: • 94% reduction in unplanned downtime • 27% improvement in system availability during peak demand periods • 16% reduction in maintenance costs despite increased maintenance activities • Enhanced resilience during two extended grid outage events in 2023 4.2. Data Center Implementation: EdgeCore Digital Infrastructure EdgeCore's 28 MW data center in Sterling, Virginia implemented a 4.6 MW solar PV system with the RCSO framework as a central element of its sustainability and reliability strategy. The facility maintains Tier IV certification, requiring 99.995% uptime. Implementation highlights include: • System Architecture: Ground-mount (3.8 MW) and rooftop (0.8 MW) arrays with N+1 redundancy in inverter systems • Stress Condition Design: Enhanced system hardening against electromagnetic interference, cyber threats, and severe weather events • Maintenance Protocol: AI-augmented predictive maintenance system with component-specific optimization The data center case study demonstrated: • Successful maintenance of Tier IV uptime requirements (100% during the 18-month study period) • 23% reduction in total maintenance costs compared to conventional protocols • 8.3% performance improvement under high ambient temperature conditions • Effective response to three severe weather events without performance degradation 5. Results and Analysis 5.1. Performance under Stress Conditions Analysis of system performance across the 34 study sites revealed significant variations in performance degradation under different stress conditions. Figure 2 illustrates comparative performance degradation across different facility types and environmental stressors. World Journal of Advanced Research and Reviews, 2025, 26(03), 2267-2281 2273 Figure 2 Performance degradation comparison under various stress conditions for solar PV systems with and without RCSO implementation The data demonstrates that solar PV systems in critical infrastructure without RCSO implementation experienced performance degradation of 14-37% under extreme conditions, while those with comprehensive RCSO implementation maintained performance within 3-12% of baseline capacity. Key findings include: • Temperature Extremes: Systems with RCSO implementation demonstrated 62% less performance degradation during high-temperature events (>100°F) compared to conventionally maintained systems. • Grid Instability: During voltage fluctuation events, RCSO-optimized systems maintained 88% of rated output compared to 61% in conventional systems. • Dust/Soiling: Optimized cleaning protocols based on RCSO principles reduced soiling-related losses by 74% in arid regions. • Severe Weather: Hurricane-exposed facilities with RCSO implementation recovered full functionality within 8 hours of event cessation, compared to 47 hours for conventional systems. 5.2. Reliability Metrics and Comparative Analysis Comprehensive reliability analysis was conducted using four primary metrics across all study sites. Table 2 presents a comparative analysis of these metrics between conventional maintenance approaches and RCSO implementation. Table 2 Reliability Metric Comparison by Maintenance Approach Reliability Metric Conventional Approach (Average) RCSO Implementation (Average) Improvement (%) Mean Time Between Failures (MTBF) 1,876 hours 5,324 hours 183.8% Mean Time To Repair (MTTR) 18.4 hours 6.2 hours 66.3% System Availability 92.7% 98.4% 6.1% Performance Ratio Under Stress 68.3% 84.5% 23.7% Source: Compiled from case study operational data, 2022-2024 The most significant improvements were observed in Mean Time Between Failures, indicating that the RCSO framework's preventive measures substantially reduced failure frequency. Mean Time To Repair improvements suggest that the framework's diagnostic capabilities and maintenance protocol optimization enabled more efficient fault resolution. World Journal of Advanced Research and Reviews, 2025, 26(03), 2267-2281 2274 5.3. Cost-Benefit Analysis Implementation of the RCSO framework requires initial investment in advanced monitoring systems, staff training, and process development. Figure 3 illustrates the cumulative cost comparison between traditional maintenance approaches and RCSO implementation across a 10-year operational period. Figure 3 Cumulative cost comparison between conventional maintenance and RCSO implementation over 10-year system lifecycle Cost analysis reveals: • Initial Implementation Costs: RCSO implementation required average initial investment of $0.12/W for existing systems and $0.08/W when integrated during system design. • Operational Cost Reduction: Annual maintenance costs averaged 18% lower for RCSO-implemented systems despite increased monitoring and preventive activities. • Downtime Cost Avoidance: Reduced unplanned downtime yielded average savings of $147,000 annually per facility (ranging from $42,000 for small emergency response facilities to $824,000 for large data centers). • Return on Investment: Average ROI for RCSO implementation was achieved in 14.2 months across all facility types. The analysis demonstrates that RCSO implementation yields significant financial benefits beyond reliability improvements, making it economically viable even in budget-constrained facilities. 6. Optimization Framework Implementation Guide The successful implementation of the RCSO framework requires a structured approach tailored to specific facility characteristics. Figure 4 presents a decision-making flowchart for implementing optimization strategies based on facility type, system configuration, and operational priorities. World Journal of Advanced Research and Reviews, 2025, 26(03), 2267-2281 2275 Figure 4 Decision-making flowchart for RCSO strategy implementation in critical infrastructure facilities 7. Implementation Framework 7.1. Implementation Phases For optimal results, RCSO implementation should proceed through the following phases: 7.1.1. Assessment and Baseline Establishment • Comprehensive system audit and performance baseline documentation (Williams and Rodriguez, 2023) • Critical component identification and failure impact analysis (Chen et al., 2024) • Operational requirement definition and performance prioritization (Patel and Nguyen, 2023) 7.1.2. System Enhancement • Strategic redundancy implementation based on criticality assessment (Blackwell and Harrison, 2024) • Monitoring system upgrades or implementation (Jefferson and Kumar, 2023) • Component replacement or upgrading for identified weak points (Sharma et al., 2024) 7.1.3. Protocol Development • Customized maintenance schedule optimization (Martinez and Lee, 2023) • Failure response protocol development (Thompson and Wilson, 2024) • Staff training and capability development (Gonzalez and Petersen, 2023) 7.1.4. Integration and Validation • Verification testing under simulated stress conditions (Richardson et al., 2024) • Integration with existing facility management systems (Liu and Johnson, 2023) • Performance validation against established baselines (Kapoor and Winters, 2024) 7.1.5. Continuous Improvement • Ongoing data collection and analysis (McKenzie and Davidson, 2023) • Periodic reassessment and protocol refinement (Yamamoto and Okafor, 2024) • Incorporation of emerging technologies and methodologies (Ferguson and Edwards, 2023) According to a longitudinal study of 28 critical infrastructure facilities, organizations that followed a structured implementation approach demonstrated a 37% reduction in solar system-related incidents compared to those