Common Solar Panel Faults Detected by Monitoring Systems and How to Fix Them Early

As solar power continues to play a central role in the UK’s transition to renewable energy, more businesses are investing in solar photovoltaic (PV) systems to cut carbon emissions and reduce long-term energy costs. Yet, like any complex technology, solar systems can experience performance issues over time. Identifying common solar panel faults early is crucial to maintaining energy output, protecting equipment, and ensuring a strong return on investment.

Solar faults can arise from various causes, such as environmental conditions, component degradation, or installation errors, and may go unnoticed without the right monitoring tools in place. Left unchecked, these issues can lead to reduced generation, safety risks, or expensive system repairs. This is where modern solar monitoring systems make a difference. By continuously tracking key performance indicators like voltage, current, and energy yield, they provide real-time insights that help operators detect and resolve faults before they escalate.

For commercial properties, manufacturing facilities, and public sector sites, understanding how these systems work, and what faults they can uncover, is vital for maintaining operational efficiency. In this article, we’ll explore the most common solar panel faults, how monitoring systems detect them, and the practical steps you can take to fix them early. Along the way, we’ll highlight best practices for performance optimisation, preventive maintenance, and the long-term benefits of proactive monitoring.

Whether you manage a rooftop array, a solar carport, or a ground-mount installation, this guide will help you make informed decisions to safeguard your solar investment and keep your system performing at its best.

Why Identifying Common Solar Panel Faults Early Matters?

Solar power is one of the most reliable and low-maintenance energy solutions available today. However, even the most robust systems can experience issues over time. Identifying common solar panel faults early helps maintain efficiency, protect investments, and prevent costly downtime.

Modern monitoring systems give businesses real-time visibility into their solar PV performance. They track energy production, detect abnormalities, and alert operators to faults before they become serious problems. For UK companies managing large solar installations, proactive monitoring is no longer optional, it is essential for ensuring long-term reliability and return on investment.

Understanding Common Solar Panel Faults and Their Impact

Understanding the common solar panel faults that can occur within a PV system is essential for maintaining long-term energy performance and preventing costly disruptions. These faults can develop gradually over time due to environmental wear, component degradation, or electrical imbalances. For commercial systems generating thousands of kilowatt-hours each month, even a small fault can lead to significant financial and operational losses if left unaddressed.

Monitoring systems play a crucial role in identifying these faults early, ensuring that any performance issues are resolved before they affect overall energy yield. Broadly, common solar panel faults can be classified into three categories: electrical faults, physical or environmental faults, and performance-related faults.

1. Electrical Faults

• Inverter errors: The inverter is the “brain” of the system. When it fails, the entire system’s output can drop to zero.
• String imbalance: When one or more panels underperform, the entire string’s performance suffers.
• Ground faults or wiring issues: Can trigger safety shutdowns or energy losses.

2. Physical or Environmental Faults

• Cracked or delaminated modules: Caused by extreme weather or material fatigue.
• Water ingress or corrosion: Compromises internal components and safety.
• Shading from nearby trees or structures: Reduces power generation significantly.

3. Performance-Related Faults

• Soiling and dirt accumulation: Dust and debris reduce efficiency by up to 10–15%.
• Hotspots or PID (Potential Induced Degradation): Uneven heating or voltage leakage can degrade panels permanently.

How Monitoring Systems Detect Common Solar Panel Faults?

Monitoring systems are the backbone of efficient solar operation, giving real-time insight into system health, performance, and energy yield. They allow operators to detect common solar panel faults quickly and accurately, often before they become visible or cause major power losses.

The Role of Monitoring in Solar PV Performance

Solar monitoring systems work like a continuous health check for your installation. They track the performance of every component, from individual modules to inverters, and compare actual energy output against predicted performance based on sunlight levels, temperature, and historical data.

If a component underperforms or behaves abnormally, the system flags it instantly. For commercial properties managing multiple sites or large rooftop systems, this visibility is invaluable in preventing downtime and maintaining consistent returns.

How Monitoring Systems Identify Faults?

Monitoring systems detect common solar panel faults by collecting and analysing multiple data points in real time, including:

• Voltage and Current: Sudden drops may signal wiring faults, string imbalance, or inverter malfunction.
• Power Output: Consistent underperformance suggests module degradation, shading, or soiling.
• Temperature Sensors: Elevated temperatures can indicate hotspots or electrical resistance.
• Irradiance Sensors: Compare expected vs. actual energy generation to highlight anomalies.

Data from these sensors is transmitted to a central dashboard or cloud-based software, which displays system performance and automatically alerts operators when irregularities are detected.

Automated Fault Detection vs Manual Inspection

Monitoring technology outperforms manual inspections in speed, precision, and long-term reliability.

Automated systems can detect common solar panel faults long before visible signs appear, often identifying small voltage discrepancies or subtle temperature differences invisible to the naked eye.

Types of Monitoring Systems

Depending on system size and complexity, there are several levels of monitoring that help identify and resolve common solar panel faults:

1. Inverter-Level Monitoring: The inverter provides essential fault codes and real-time data but may not show detailed module-level information. 
2. String-Level Monitoring: Detects performance inconsistencies between groups of panels. Ideal for medium-to-large commercial installations. 
3. Module-Level Monitoring: Uses optimisers or microinverters to track each panel’s output. This high-resolution approach identifies common solar panel faults like microcracks or shading on a single module. 
4. Predictive and AI-Driven Systems: Advanced platforms use artificial intelligence to detect performance patterns, predict future failures, and optimise energy yield automatically.

Why Early Detection of Common Solar Panel Faults Is Critical?

Timely identification of common solar panel faults is one of the most important factors in maintaining optimal system performance, financial savings, and operational continuity. Faults that go unnoticed can escalate quickly, reducing generation efficiency and shortening component lifespan.

• Protecting Energy Yield and Financial Performance: Even a minor fault, such as a single shaded module or loose connector, can impact an entire string, resulting in measurable energy loss. For large commercial installations, this translates into thousands of pounds in lost revenue annually.
• Reducing Repair and Maintenance Costs: Early fault detection prevents small issues from escalating into costly failures.Preventative maintenance through monitoring is typically 30–40% cheaper than emergency repairs triggered by unnoticed faults.

• Enhancing System Lifespan and Safety: Addressing common solar panel faults promptly reduces wear on electrical components and maintains safe operating conditions. Ground faults or overheating can lead to fire hazards, particularly on large commercial roofs. Continuous monitoring ensures compliance with UK electrical safety standards (such as BS 7671) and manufacturer warranty conditions.

• Supporting Sustainability and Compliance: Many UK businesses use solar PV to meet sustainability targets or reporting frameworks like SECR (Streamlined Energy and Carbon Reporting) or ESOS (Energy Savings Opportunity Scheme). Fault-free systems ensure consistent data for carbon accounting and energy performance reporting.

What to Do When a Fault Is Detected?

When a monitoring system identifies one of the common solar panel faults, taking a structured and safe approach ensures that performance is restored quickly without compromising system integrity or safety.

Step-by-Step Troubleshooting Process

1. Verify the alert: Confirm whether the monitoring system’s alert is accurate by checking the data trend and inverter dashboard.
2. Inspect the site visually: Look for visible issues such as debris, shading, or physical damage to panels and cabling.
3. Cross-check affected strings or modules: Compare the voltage and current data of the affected section against nearby strings.
4. Record findings: Document all readings, photos, and error codes for reference or warranty claims.
5. Restart or isolate equipment if safe to do so: Some faults may clear with a simple inverter reset, but avoid touching live components without qualification. 

Note: If in doubt, do not attempt electrical repairs. Certain common solar panel faults, such as ground faults or inverter errors, require qualified engineers for safe resolution.

When to Contact a Professional?

Certain faults can only be safely diagnosed and corrected by certified professionals. You should always contact a solar O&M provider when:

• The inverter displays persistent fault codes.
• The system experiences repeated shutdowns.
• Energy yield drops significantly despite normal irradiance.
• There are signs of overheating, smoke, or corrosion. 

Professional teams like EvoEnergy’s Maintenance and Monitoring Division can remotely diagnose system data, dispatch field engineers, and restore functionality swiftly, minimising downtime and maximising safety.

How to Maintain Optimal Performance and Prevent Common Solar Panel Faults?

Prevention is the best cure. Regular maintenance and data reviews reduce the likelihood of common solar panel faults recurring.

1. Routine Maintenance Practices

• Schedule biannual inspections for large commercial sites.
• Ensure panels are clean and free of obstructions.
• Verify inverter firmware updates and data connectivity.

2. Analysing Monitoring Reports

• Compare month-on-month yield to detect early performance dips.
• Use predictive analytics to identify ageing components.
• Investigate recurring alarms to spot systemic issues.

3. Professional Monitoring and Maintenance Plans

Engaging a certified operations and maintenance (O&M) provider ensures long-term reliability. EvoEnergy offers bespoke monitoring packages for commercial solar systems across the UK, combining real-time analytics with on-site technical support.

Key Considerations When Choosing a Solar Monitoring Solution

The right platform can make fault detection far more effective. When selecting a solution to identify common solar panel faults, consider the following:

1. System compatibility: Works seamlessly with your inverter and communication protocols.
2. Data accuracy and frequency: High-resolution monitoring ensures accurate fault diagnosis.
3. Alert management: Instant notifications via app or email.
4. Reporting tools: Clear dashboards and exportable performance summaries.
5. Support services: Access to professional maintenance when needed.

Stay Ahead of Common Solar Panel Faults with Proactive Monitoring

Identifying common solar panel faults early is only the first step in protecting the performance, safety, and financial return of a commercial solar PV system. While modern monitoring platforms provide valuable real-time insight into system behaviour, data alone does not resolve faults, prevent repeat issues, or safeguard long-term asset value.

This is where structured Operations and Maintenance, often referred to as Aftercare, becomes critical. A professional Aftercare programme ensures that alerts generated by monitoring systems are correctly interpreted, prioritised, and addressed by qualified engineers who understand both the electrical and operational context of commercial solar assets. From remote diagnostics and fault resolution to planned preventative maintenance, thermal inspections, cleaning regimes, and performance recommissioning, effective Aftercare transforms monitoring insights into tangible performance improvements.

For UK businesses operating rooftop, ground-mount, or solar carport installations, proactive Aftercare also plays a key role in maintaining compliance with electrical safety standards, protecting manufacturer warranties, and supporting accurate energy and carbon reporting. Rather than reacting to failures after energy losses occur, a dedicated O&M strategy helps prevent common solar panel faults from developing in the first place.

EvoEnergy’s Operations and Maintenance (Aftercare) services are designed specifically for commercial-scale systems, combining advanced monitoring, engineering expertise, and responsive on-site support. By pairing intelligent fault detection with long-term Aftercare, businesses can reduce downtime, maximise energy yield, and ensure their solar investment continues to deliver value year after year.

Speak with EvoEnergy’s monitoring and maintenance experts today to ensure your solar system delivers maximum output, minimum downtime, and measurable returns for years to come.