As solar energy continues to expand as a reliable and sustainable power source, ensuring the performance and longevity of photovoltaic (PV) systems has become more critical than ever. IEC 62446–3:2017 provides a global standard for thermal inspections of PV systems, offering clear guidelines for accurately identifying faults using drone technology. This standard ensures that inspections meet a consistent benchmark, enabling the detection of critical issues like hot spots, cell degradation, and electrical faults.
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By adhering to the IEC 62446-3:2017 standards, businesses can ensure that their solar panel inspections are thorough, accurate, and reliable. This not only helps to maintain the performance and longevity of their solar panels but also contributes to the overall integrity and credibility of the solar industry.
During new site commissioning and ongoing solar inspections, adhering to IEC 62446–3:2017 standards become particularly important. A thorough, compliant inspection establishes a high-quality baseline for the system, ensures early detection of potential issues, and holds EPCs accountable. These inspections not only safeguard the system’s initial performance but also lay the groundwork for reliable operation and long-term efficiency.
In addition, it should be noted that the current version of the IEC 62446-3:2017 standards have been in place for several years now, and a new version of the standards for drone-based solar PV thermography is currently under development to address advancements in drone technology and data analysis methods.The updated standard aims to refine guidelines for thermal imaging resolution, environmental condition monitoring, and anomaly classification to improve accuracy and reliability further. While no official release date has been confirmed, experts suggest the update could be published approximately October 2025 as international working groups finalize the revisions.
What is an IEC-Compliant Drone Solar Inspection?
An IEC-compliant drone solar inspection follows the guidelines specified in IEC 62446–3:2017, the international standard for testing and documenting faults in photovoltaic (PV) systems using infrared (IR) thermography. These standards specify requirements for image resolution, flight altitude, and sensor accuracy to ensure the precise identification of anomalies, such as hot spots, potential-induced degradation (PID), and module defects.
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During an inspection, drones capture high-resolution thermal images and visible-light photos of the solar array. This data provides a detailed view of each module’s performance and highlights subtle faults that could otherwise go unnoticed. By adhering to these stringent standards, an IEC-compliant inspection delivers consistent, reliable results that meet the needs of stakeholders, from EPCs and utility companies to insurers and warranty providers.
How Does IEC Compliance Improve Inspection Accuracy?
IEC-compliant inspections significantly enhance the accuracy of fault detection in solar PV systems. By adhering to IEC 62446–3:2017 standards, inspections are conducted with high-resolution thermal imaging and precise sensor sensitivity, enabling the detection of critical issues that could be missed in non-compliant inspections.
Key faults such as cell cracking, potential-induced degradation (PID), and interconnect degradation are often subtle and require detailed imaging to identify. For example, cell-level hotspots and microcracks might appear as very faint anomalies in a non-compliant inspection but are clearly visible in the higher-quality data captured under IEC guidelines.
What's included in YOUR GUIDE...
Techniques for Exposing Warrantiable Items on Your PV Sites.
A Proven Roadmap for Successfully Implementing Drones in Solar.
Strategies for Identifying DC Losses and Avoiding Downtime.
Non-compliant inspections, often conducted at higher altitudes, take less overall time to complete but result in less detailed images. This isn’t necessarily due to lower-resolution equipment but rather the relationship between altitude and pixel coverage. Just like any camera, thermal cameras are made up of pixels, and as altitude increases, each pixel covers more surface area on the module. With fewer pixels per hotspot, the precision of temperature measurements and image clarity deteriorates, making it harder to accurately identify defects.
Source: IEC 62446–3:2017
Are There Additional Costs for an IEC-Compliant Inspection?
Yes, IEC-compliant inspections typically incur higher costs due to the rigorous standards involved. One key factor is increased flight time; drones must fly at lower altitudes to capture high-resolution thermal and visual images, which slows the overall inspection process. Additionally, IEC-compliant inspections require comprehensive reporting. This involves processing a larger volume of images and tagging each anomaly with detailed descriptions, which increases the workload for data analysts.
While these factors raise costs, the investment is well worth the cost. The higher resolution and detailed reporting ensure no critical faults are overlooked, providing a thorough and accurate assessment of the PV system’s health. This level of precision helps EPCs, and asset managers address potential issues early, reducing downtime and long-term maintenance costs. The detailed documentation also helps with insurance and manufacturer requirements, supporting warranty claims and reducing risks of claim denial.
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Do Warranty Claims Require IEC-Standard Inspections?
IEC-compliant data plays a critical role in supporting warranty claims for solar PV systems. Insurers often require inspection reports that adhere to IEC 62446–3:2017 standards, as they provide the detailed, high-resolution evidence they require.
Non-IEC-compliant inspections, however, may lack the necessary detail, leading to challenges in claim approval. For instance, low-resolution thermal images might fail to clearly document issues like microcracks or hotspot severity, leaving insurers without sufficient evidence to validate a claim.
By providing thorough and standardized documentation, IEC-compliant inspections reduce the risks for asset owners and ensure coverage for necessary repairs or replacements.
What's included in YOUR GUIDE...
Techniques for Exposing Warrantiable Items on Your PV Sites.
A Proven Roadmap for Successfully Implementing Drones in Solar.
Strategies for Identifying DC Losses and Avoiding Downtime.
Are there U.S. standards like those from NEC, ASNT, UL, or NFPA that apply to drone thermography inspections for PV?
Currently, no U.S.-based organizations such as NEC (National Electrical Code), ASNT (American Society for Nondestructive Testing), UL (Underwriters Laboratories), or NFPA (National Fire Protection Association) have drone-specific standards for solar PV thermography inspections. The European IEC 62446–3:2017 remains the primary global standard, addressing aerial thermographic inspections of PV systems.
While organizations like NFPA have guidelines on thermal inspections (e.g., NFPA 70B for electrical maintenance), these are tailored to ground-based or handheld inspections rather than drone use. Similarly, ASNT offers general guidelines for nondestructive testing personnel certification but lacks drone-specific criteria.
This gap underscores the significance of adhering to IEC standards to ensure inspection consistency, accuracy, and global compliance for PV systems. As the demand for drone inspections grows, U.S.-based standards may eventually evolve to address this need.
Which Anomalies Are Often Missed Without an IEC-Compliant Inspection?
Non-IEC-compliant inspections often overlook critical issues, including but not limited to:
Potential-Induced Degradation (PID):
- Subtle degradation of module output over time.
- Difficult to detect without high-resolution imaging.
Microcracking:
- Tiny fractures that can grow and cause significant power loss.
- Often invisible in low-quality thermal images.
Overheating Split-Phase Junction Boxes:
- Potentially hazardous faults leading to electrical failure or fire.
- Requires detailed thermal imaging for early detection.
Failed Junction Box Identified Using Drone Thermography
Absolute Temperature Accuracy:
- The quality of the temperature measurements being documented.
- Highly technical process to achieve accurate Delta T (ΔT) temperatures between modules.
The Long-Term Impact
When anomalies are missed, they can escalate into larger, more expensive problems over time. Faults such as PID or microcracks can significantly reduce the energy output of the PV system, while overheating junction boxes, which can become serious safety risks. As issues worsen, downtime increases, repairs become costlier, and overall system efficiency declines. IEC-compliant inspections address these risks by ensuring early and accurate fault detection, enabling timely interventions that protect the system’s performance and longevity.
Source: IEC 62446–3:2017
Pros and Cons of IEC-Compliant Inspections
IEC-Compliant Pros
- Higher Accuracy and Fault Detection: Ensures subtle issues like microcracks, PID, and thermal anomalies are identified early.
- Improved System Reliability and Performance: Facilitates timely maintenance, reducing downtime and maximizing energy production.
- Baseline of Data for New Systems: Establishes a detailed reference point for future inspections and performance tracking.
- Stronger Evidence for Warranty Claims: Provides standardized documentation that aligns with manufacturer acceptance requirements.
IEC-Compliant Cons
- Longer Inspection Time and Higher Costs: Drones need to fly at lower altitudes with slower passes, increasing field time and expense.
- Increased Data Processing Workload: A larger number of images requires more time and effort for analysis and reporting.
- More Complexity in Meeting Standards: Requires specialized knowledge of equipment, trained personnel, and meticulous adherence to guidelines.
Getting Started with IEC-Compliant Inspections
IEC-compliant drone solar inspections are a vital component of ensuring the reliability, efficiency, and long-term performance of PV systems. By adhering to IEC 62446–3:2017 standards, these inspections provide unmatched accuracy in detecting critical faults, establish a strong baseline for new system commissioning, and align with the documentation requirements for warranty claims and insurance coverage. While IEC-compliant inspections may involve higher costs and additional processing time, the value they deliver in preventing costly downtime and maintaining optimal energy production far outweighs these challenges.
IEC-compliant inspections are not just a recommendation—they are the standard for ensuring the success of your solar PV projects. By partnering with a skilled drone service provider, you can ensure that your systems meet compliance standards and achieve peak performance. At The Drone Life, our FAA-licensed and OSHA-certified pilots bring unparalleled expertise to every project. Schedule a free consultation with us today and discover how we can support your solar PV inspections, from commissioning to ongoing maintenance.
What's included in YOUR GUIDE...
Techniques for Exposing Warrantiable Items on Your PV Sites.
A Proven Roadmap for Successfully Implementing Drones in Solar.
Strategies for Identifying DC Losses and Avoiding Downtime.
