Solar panels are remarkably durable, but like any technology exposed to the elements year-round, they can experience performance issues that impact your solar energy production. From shading and weather damage to inverter malfunctions and wiring faults, most solar problems are preventable with proper installation and regular maintenance.
In this comprehensive guide, we explore what causes the most frequent solar panel issues, how to identify them, and practical solutions to keep your system running at maximum capacity for decades.
What Causes Solar Panel Issues?
Solar panel issues are caused by various factors, such as:
- Environmental factors. These include extreme weather conditions like hail, heavy snow, and temperature fluctuations that put stress on panels and connections. Dust accumulation, bird droppings, and debris block sunlight absorption, while moisture infiltration leads to corrosion and electrical faults.
- Mechanical factors. Often, improper installation practices result in inadequate mounting hardware, loose wiring connections, and insufficient ventilation around solar system components. Manufacturing defects, though less common with quality brands, can cause premature cell degradation and hot spot formation.
- Electrical factors. These issues arise from failing inverters, damaged charge controllers, and degraded bypass diodes that prevent proper power conversion and distribution. Additionally, grid compatibility issues and voltage fluctuations can trigger anti-islanding protection, causing unexpected system shutdowns even during optimal solar conditions.
12 Most Common Solar Panel Issues and Tips for Fixing
Now that we’ve covered the factors that cause solar panel issues, let’s examine the most common solar panel faults associated with these factors so you can quickly diagnose problems and implement solutions before they escalate.
#1. Shading and Weather-Related Obstructions
Shading is one of the most significant solar panel issues affecting system performance. Even partial shade on a single panel can reduce your entire array's output by up to 10%. Trees growing taller, new construction casting shadows, or accumulated debris like leaves and snow all create shading problems that impact solar panel efficiency.
The solution is simple. Trim overhanging branches seasonally, install solar panels away from potential shade sources, and consider adding microinverters or power optimizers to minimize shading impact on individual panels. For winter months, invest in a soft-bristled snow rake designed for solar panels and remove accumulations before they freeze into ice that blocks sunlight. Use the snow rakes only for ground-mounted or safe-to-reach systems.
#2. Dirty or Damaged Solar Panels
Dust, bird droppings, and environmental pollutants accumulate on panel surfaces, reducing light absorption. In agricultural or industrial areas, this buildup happens faster, requiring more frequent cleaning. Physical damage from hail, falling branches, or installation mishaps creates micro-cracks that worsen over time, leading to hot spots and electrical failures.
Regular solar panel cleaning every 6-12 months with soft brushes and deionized water prevents buildup that causes permanent etching. Inspect panels quarterly for cracks, discoloration, or delamination signs. Minor surface damage might be repairable with specialized sealants, but panels with extensive cracking or electrical damage require professional replacement.
#3. Low Output
Low solar output often stems from multiple factors working together. Degradation rates of 0.5-0.8% annually are normal, but accelerated degradation indicates underlying problems. System undersizing, incorrect tilt angles, or panels operating above optimal temperature ranges all contribute to disappointing production levels that fall short of projected savings.
Start by comparing actual production against expected values using monitoring data. Check for shading, soiling, or connection issues first. If output remains low, have a professional verify your system's DC/AC ratio, confirm proper grounding, and test individual panel outputs.
#4. Wiring and Connection Faults
Faulty wiring causes intermittent power loss, arc faults, and potential fire hazards in solar systems. Loose connections from thermal cycling, corroded terminals from moisture infiltration, or damaged cables from rodent activity create resistance that reduces power transmission and generates dangerous heat buildup.
Inspect all visible connections monthly for signs of burning, corrosion, or looseness. Thermal imaging cameras can identify hot connections before they fail completely. Professional electricians should handle any wiring repairs, ensuring connections meet torque specifications and replacing damaged MC4 connectors or DC cables.
#5. Inverter Issues
The inverter converts DC electricity from panels into usable AC power, making inverter problems particularly disruptive to system operation. Common failures include:
- Overheating from inadequate ventilation
- Ground faults from moisture damage
- Component degradation after 10-15 years of continuous operation
- Error codes, unusual noises, or complete shutdown
Ensure adequate airflow around inverters by maintaining 12-inch clearance on all sides. Clean air filters monthly in dusty environments. For older systems, upgrading to a hybrid inverter provides improved efficiency, battery compatibility, and enhanced monitoring capabilities. String inverter failures might warrant switching to microinverters for better individual panel management and reduced single-point failure risks.
#6. Battery Issues
In hybrid solar systems with energy storage, battery problems impact backup power availability and self-consumption rates. Symptoms include reduced capacity, inability to hold charge, or premature voltage drops under load. Improper charging parameters, extreme temperatures, or deep discharge cycles accelerate battery degradation.
Maintain batteries within manufacturer-specified temperature ranges with combiner boxes, ventilation, or heating as needed. Program charge controllers for appropriate battery chemistry settings because lithium batteries require different parameters than lead-acid types.
#7. Poor Installation or Low-Quality Components
Substandard installation practices and low-quality components create cascading failures throughout your solar array. Improper grounding increases lightning damage risk, while inadequate mounting systems allow panels to shift, stressing connections. Cheap components might save money initially, but fail prematurely, requiring expensive replacements.
Always verify installer certifications and request detailed equipment specifications before committing to any solar kit. Quality installations use tier-one panels with 25-year warranties, NEMA-rated enclosures for outdoor equipment, and properly torqued stainless steel hardware. If you suspect installation issues, hire an independent inspector to verify code compliance and identify necessary corrections before problems compound.
#8. Hot Spots
Hot spots occur when individual cells overheat due to shading, manufacturing defects, or physical damage. These localized temperature increases, sometimes exceeding 200°F, permanently damage cell structure and can cause fires in extreme cases. Thermal imaging reveals hot spots as bright areas significantly warmer than surrounding cells.
To prevent hot spots, proper system design is key. That way, you avoid potential shading scenarios. Install bypass diodes to route current around damaged cells. For existing hot spots, determine whether cleaning, trimming vegetation, or panel replacement offers the most cost-effective solution.
#9. PID (Potential Induced Degradation)
Potential induced degradation of solar panels occurs when voltage differences between panels and the ground create leakage currents that degrade cell performance. High humidity, elevated temperatures, and system voltages above 600V accelerate PID effects, potentially reducing output by up to 30% in extreme cases. Symptoms include unexpected power drops in specific strings and visible cell discoloration patterns.
Combat PID by ensuring proper system grounding and using PID-resistant solar panels in high-voltage installations. Anti-PID boxes reverse degradation effects by applying opposite polarity voltage during non-production hours. For severe cases, module-level power electronics isolate panels from system voltage, preventing further degradation while maintaining production.
#10. LID (Light Induced Degradation)
Light-induced degradation causes approximately 2-3% power loss within the first hours of sunlight exposure as oxygen-boron complexes form in silicon cells. While manufacturers account for LID in power ratings, excessive degradation beyond specifications indicates quality issues. This initial degradation stabilizes but permanently reduces panel capacity below nameplate ratings.
Choose panels with anti-LID technology like gallium-doped silicon or PERC cells with reduced LID susceptibility. Since LID is irreversible, understanding the actual stabilized power output helps accurately size systems to meet energy needs after initial degradation occurs.
#11. Delamination and Moisture Ingress
Delamination occurs when protective layers separate, allowing moisture penetration that corrodes internal components. White discoloration, bubbling backsheets, or visible moisture indicate seal failures requiring immediate attention. Once moisture enters, corrosion accelerates, causing irreversible damage within weeks.
Inspect panel edges and junction boxes quarterly for seal integrity. Small delamination areas might be repairable using specialized adhesives and edge sealants. However, panels with extensive delamination or internal moisture require replacement.
#12. Grid Connection Problems
Grid-tied systems experiencing frequent disconnections or failure to export power often suffer from grid compatibility issues. Voltage fluctuations, frequency variations, or updated utility requirements can trigger anti-islanding protection, shutting down production even during perfect weather conditions.
Review inverter settings against current utility interconnection requirements—standards change periodically, requiring firmware updates or setting adjustments. Install power quality monitoring equipment to document grid conditions during disconnection events. For persistent issues, consider adding a solar system with battery backup to maintain production during grid disturbances.
How to Identify Solar Panel Issues
Identifying solar panel issues early on prevents minor problems from becoming major failures. Combining technology with regular inspections is a good approach to timely solar system troubleshooting. Let’s see how to do this in more detail.
Use a Monitoring System
Modern monitoring platforms track individual panel performance, identifying underperforming units before system-wide impacts occur. Real-time production data compared against weather conditions reveals efficiency drops, indicating solar panel degradation or component failures. Set alerts for production drops exceeding 10% from expected values, triggering immediate investigation.
Physical Inspection Checklist
Quarterly visual inspections catch problems that monitoring systems might miss. Check for cracked glass, frame damage, or burn marks on panels. Examine mounting hardware for rust, loose bolts, or shifting that stresses electrical connections. Inspect combiner boxes and disconnect switches for signs of overheating, water intrusion, or insect infiltration that causes arc faults.
Document findings with photographs, comparing against previous inspections to identify progressive changes. Pay special attention after severe weather events when wind, hail, or lightning may cause hidden damage.
Electrical Testing (Performed by Professionals)
Annual professional testing with specialized equipment provides a comprehensive system health assessment beyond visual inspection capabilities. I-V curve tracing identifies degradation patterns, shading impacts, and connection resistance issues. Insulation resistance testing reveals moisture ingress or ground faults before they cause shutdowns.
Thermal imaging during peak production reveals hot spots, failing bypass diodes, or overheating connections invisible to standard inspections. Professionals also verify proper grounding, arc-fault protection functionality, and compliance with updated electrical codes that change periodically.
How to Prevent Solar Panel Issues Long-Term
Proactive solar panel maintenance significantly extends system lifespan and optimal performance throughout decades of operation. Here are a few strategies to follow:
- Install weather mitigation components. These include lightning arrestors, surge protection devices, and rapid shutdown systems meeting the latest NEC requirements. Add critter guards preventing rodent damage to wiring while maintaining proper ventilation. In hail-prone regions, consider protective screens or panels with reinforced glass rated for larger hailstone impacts.
- Implement MLPE technology. Module-Level Power Electronics, including power optimizers or microinverters that mitigate shading impacts, enable individual panel monitoring, and reduce DC arc-fault risks. These components also simplify system expansion by allowing mixed panel types and orientations without string-matching constraints.
- Schedule professional maintenance annually. This includes torque checks on all connections, cleaning of ventilation systems, and firmware updates for smart components. Professionals identify developing issues before they impact production, often covered under maintenance agreements that include performance guarantees.
- Maintain detailed documentation. Installation reports, equipment specifications, warranty information, and maintenance records prove invaluable for solar panel warranty issues, claims, and helps technicians quickly diagnose problems. Create a maintenance log tracking cleaning dates, inspection findings, and any repairs performed.
Ready to Troubleshoot and Prevent Solar Panel Issues?
Check out Portable Sun’s range of solar panels, accessories, and monitoring tools to keep your system safe and efficient.
Final Thoughts
Understanding common solar panel issues allows you to maintain peak system performance through proactive monitoring and timely interventions. While solar technology proves remarkably reliable with 25-30 year lifespans, addressing minor problems quickly prevents cascading failures.
Regular maintenance, quality components, and professional support ensure your solar system continues delivering clean, affordable electricity for decades. With proper care, solar installations provide reliable solar power that pays dividends through energy independence and environmental stewardship.
Solar Panel Issues FAQ
#1. What is the biggest problem with solar panels?
The biggest problem is typically shading, which can reduce the entire system’s output by more than 10% even when affecting just one panel. Other major concerns include inverter failures after 10-15 years and gradual degradation, reducing efficiency over time.
#2. What are the signs of a faulty solar panel?
Visual signs include cracks, discoloration, burn marks, or delamination. Performance indicators show significant power drops compared to other panels, hot spots visible through thermal imaging, or complete failure to generate power during sunlight.
#3. What causes one panel to stop working?
Individual panel failures result from physical damage, failed bypass diodes, severe hot spots, or complete junction box failure. Broken internal connections from manufacturing defects or moisture ingress can also cause a total panel shutdown.
#4. How do I know if my inverter is bad?
Error codes on display screens, unusual buzzing or clicking sounds, frequent grid disconnections, or zero power production despite sunny conditions indicate inverter problems. Red warning lights or complete display failure require immediate professional attention.
#5. Can weather permanently damage my solar panels?
Extreme weather can cause permanent damage—large hail creates micro-cracks, lightning strikes destroy electronics, and sustained winds can tear panels from mountings. However, quality panels withstand most weather conditions when properly installed.
#6. How long do solar panels really last?
Quality solar panels last 25-30 years, maintaining 80-85% original capacity. With proper maintenance, many systems operate efficiently beyond 30 years, though inverters typically require replacement after 10-15 years of service.
Disclaimer: The content on Portable Sun is for informational purposes only. Electrical work can be dangerous—always consult a qualified professional. We are not liable for any injuries, damages, or losses from installation or use. Always follow local regulations and safety guidelines when handling electrical components.