For building owners who have invested in solar energy, the expectation is clear: consistent, high-yield performance and a strong return on investment. The long-term success of any solar installation, however, depends in part upon a proactive approach to maintenance—particularly through regular, comprehensive and insightful PV modules inspections.
Understanding the Risks: Common PV Systems Failures
Solar photovoltaic (PV) arrays are intricate systems that operate under a wide range of environmental and operational stresses. Over time, these stresses can lead to various types of failures which, if not promptly detected and repaired, may significantly reduce system performance and profitability.
Failures in PV systems can occur at several scales. At the sub-module level, for example, individual cell failures within a module can degrade overall performance, while bypass diode failures may cause entire sections of a module to underperform and potentially overheat. Full module failures—often due to manufacturing defects, aging, or environmental exposure—can severely reduce system energy output. At a broader level, string failures within series-connected groups of modules can result in substantial energy losses across the entire array.
In addition to these electrical issues, physical factors such as wiring degradation, mounting hardware problems, and surface contamination (caused by dirt, bird droppings, leaves, or other debris) also pose ongoing risks to optimal system operation.
The Role of Thermal IR Drone Technology in Inspections
While routine visual inspections are valuable, they are often insufficient for detecting subtle or internal faults. This is where thermal infrared (IR) drone technology sets a new standard for solar PV inspections. Drones equipped with thermal IR cameras can survey even large-scale arrays quickly and efficiently, requiring zero system downtime and minimal labor costs as compared to traditional inspection methods.
Thermal infrared (IR) drones detect defects by measuring temperature variations across the solar modules. For example, defective cells within modules or malfunctioning connections often create “hot spots” that are visible in thermal images. Thermal imaging is also particularly effective at identifying temperature anomalies associated with bypass diode failures, whole module malfunctions and multi-module string failures—important issues that are nevertheless often invisible during standard inspections.
By flying over installations and scanning with thermal cameras, drones can quickly and efficiently identify anomalies without direct contact. The high-resolution thermal maps generated by thermal IR drones provide precise, actionable insights, allowing maintenance teams to target specific modules or strings for repair, rather than relying on time-consuming and expensive manual checks. This allows for early defect-detection and subsequent maintenance, improving system performance and longevity.
Finally, drone-based inspections reduce the need for personnel to access rooftops or elevated structures, improving workplace safety and supporting compliance with occupational health standards.
A displaced rooftop module causing thermal anomalies in adjacent modules – discovered during a drone inspection.
Business Benefits of Regular, Periodic PV System Inspections
For building owners and managers, the benefits of incorporating thermal IR drone inspections into a regular maintenance schedule are clear. Early detection and remediation of faults ensure your array operates at peak efficiency, maximising energy yield and financial returns. Targeted maintenance minimises unnecessary labor and replacement expenses by addressing issues before they escalate. Proactive care slows system degradation, protecting your investment and supporting long-term sustainability goals. Furthermore, periodic, documented, professional inspections are often required to maintain manufacturer warranties and insurance coverage.
Best Practices for Inspection and Monitoring
To maintain optimal performance, it is advisable to engage certified specialists utilizing thermal IR-equipped drones for a comprehensive annual review. Additional PV system inspections should be scheduled following severe weather or other events that may impact system integrity. Real-time performance monitoring can be implemented to flag output anomalies between scheduled inspections, ensuring that any issues are addressed promptly.
Conclusion: Protecting Your Solar Investment
Regular solar PV inspections, utilizing thermal IR drone technology, are not just a best practice—they are a business imperative. By leveraging such advanced diagnostics, building owners can safeguard their solar assets, ensure optimal performance, and secure the long-term value of their renewable energy investments.
The author is a Swiss BAZL and US FAA licensed commercial drone pilot and CAT 1 Infrared Thermographer, and has the Solar Energy Professional Certificate from the Delft University of Technology (Netherlands).
Parhelion can help transform the future of your solar array
Parhelion Aerospace is your certified and experienced solar modules inspector in Switzerland.
Using modern, sophisticated and safe drones, Parhelion captures high-resolution visual and thermal infrared imagery of your solar modules, and analyses them for evidence of defects. We then provide you with a comprehensive report of the results. This approach provides definitive insights that serve as a reliable guide for effective repairs that protect your PV system and improve its future performance, saving money and maximising your system’s energy output.
To schedule a modern, 21st-century inspection of your solar modules, feel free to contact Parhelion. We are committed to working with you to meet your inspection needs.
Parhelion Aerospace is SORA approved, by the Swiss Bundesamt für Zivilluftfahrt (BAZL).