Technical inspection of photovoltaic panels and thermography with drones

Drone thermography is a non-destructive analysis technique based on the acquisition of infrared aerial images. This occurs thanks to the radiation emitted by the system, which is able to determine the temperature.

Thermography can be applied in all sectors where an aerial thermographic technical inspection is required. In fact, thanks to drone technology, it is possible to perform a complete mapping of the area, inspecting the object or surface quickly and easily.

At SG drones we have the possibility, thanks to our thermography drones, to perform area inspections with high performance sensors and FLIR, DJI XT2 and DJI H20T thermal cameras.

Census of photovoltaic panels

The census of photovoltaic panels performed with drones is an important part of the technical inspection of solar systems. It consists of an exhaustive and systematic collection of information on the photovoltaic panels installed in a specific photovoltaic plant or location. The main objective of the census is to obtain a complete and detailed view of all the solar panels present in the system, which allows to have an updated record of the configuration and distribution of the solar modules.

During the survey, the drone moves along the entire PV plant and captures high-resolution images of each panel. These images can be both visual and thermographic (infrared) to obtain a greater amount of data on the condition of the panels. In addition, the drones can carry out other specific measurements and tests to evaluate the performance and efficiency of the panels.

Census of photovoltaic panels with drones offers several benefits:

• Identification of damaged or defective solar panels: Images captured during the census can detect PV panels with physical damage, cracks, breaks or hot spots (HOT SPOT) that may affect system performance.
• Quality control and system condition monitoring: The census provides an up-to-date record of the condition of the panels, which facilitates monitoring over time and helps to make comparisons with previous measurements.
• Locating specific PV panels for interventions and maintenance: The information collected during the census allows for quick identification of problematic solar panels, which facilitates the planning of interventions and corrective actions.
• Evaluation of the efficiency of the installation: By having a complete view of the panels, the overall efficiency of the system can be calculated more accurately and it is possible to determine if there are areas in need of optimization.

Mapping of defective hot spots

The mapping of defective hot spots is an essential part of the technical inspection of photovoltaic panels with the use of a drone. It consists of using the thermographic images obtained during the technical inspection with drones to identify and precisely locate the hot spots («HOT SPOT») present on the solar panels.

During the technical inspection, thermographic cameras mounted on the drone capture infrared images of the photovoltaic panels in operation. Hot spots are generated when faulty, poorly connected or malfunctioning cells cause excessive heat buildup in those areas.

The mapping of defective hot spots involves the following steps:

• Thermographic image capture: The drone travels around the photovoltaic plant and captures high-resolution infrared images of the photovoltaic panels in operation. These images reveal the temperature variations in the solar panels and highlight the hot spots clearly and distinctly.
• Thermographic image processing: The thermographic images obtained are processed and analyzed to identify the hot spots present in each panel. This is done by detecting and mapping areas with unusually high temperatures.
• Correlation with electrical data: For a more accurate assessment, the areas identified as hot spots on the thermographic images are correlated with the electrical measurements collected during the technical inspection. This allows to confirm whether the hot spots correspond to faulty cells or real electrical problems (O&M).
• Report generation: Once the mapping of defective hot spots is completed, a detailed report is produced that includes the precise locations of the hot spots on each panel. This provides a complete picture of the situation and helps to plan corrective actions. These reports are provided to the client as a pdf document and are also accessible through a web platform where they can be downloaded, filtered by type of defect or temperature or even view the images taken.
• Corrective actions: With the information provided by the hot spot mapping, technicians and system owners can take specific corrective actions to repair or replace defective cells, improve electrical connections, or fix other problems affecting system performance.

Mapping faulty hot spots is essential to ensure optimal operation and performance of photovoltaic panels. By identifying and addressing problems early, energy losses are avoided and system life is extended, resulting in a higher return on investment for solar installation owners.

Monitoring of photovoltaic panels

Photovoltaic panel monitoring with drones is a continuous and systematic practice that involves regular tracking of the performance and status of solar panels installed at a specific PV plant or location using drones and telemetry technologies. It consists of the periodic collection of relevant data and measurements to evaluate the efficiency and performance of the PV panels over time.

PV panel monitoring with the use of a drone can include the following activities:

• Regular inspections: Drones are used to perform regular visual and thermographic inspections of PV panels. These inspections can take place monthly, quarterly or at other regular intervals, depending on the needs and requirements of the system.
• Image and data capture: During monitoring, drones collect high-resolution images and thermographic data from the panels. These images and data are analyzed to detect possible damage, hot spots («HOT SPOT»), shadowing, or any other problems that may affect system performance.
• Performance analysis: Energy production data obtained from the solar panels are compared with theoretical estimates and historical data. This allows the actual system performance to be evaluated and any significant deviations to be detected.
• Early detection of problems: Regular monitoring with a drone makes it possible to detect problems in the panels alone and the system at early stages, making it easier to plan corrective actions before problems escalate and affect energy production.
• Analysis of system efficiency: Continuous monitoring allows to evaluate the overall efficiency of the system over time and to make informed decisions on possible improvements and optimizations.
• Recording and documentation: All measurements and data collected during monitoring are recorded and documented to maintain a complete history of the system’s condition, which is useful for maintenance, follow-up and audit purposes.
• Alerts and notifications: In some cases, automatic alerts and notifications can be set up to inform system operators or owners of problems detected during monitoring.

Drone monitoring of photovoltaic panels is a powerful tool to ensure optimal performance and long-term efficiency of solar systems. It enables proactive and efficient management of the PV plant, as well as informed decision making to maximize solar energy production and extend the lifetime of the panels.

Performance analysis and post-production

Performance and post-production analysis is a critical phase in the technical inspection of photovoltaic panels with drones. After visual and thermographic inspections and other field measurements, the collected data is processed and analyzed to obtain detailed and valuable information on the performance and condition of the solar panels.

The performance analysis and post-production process includes the following stages:

• Data processing: Data collected during inspections using a drone, such as visual images, thermographs, are downloaded and organized for analysis.
• Data correlation: Visual and thermographic data from each specific panel are linked, allowing any physical damage or defects detected to be related to hot spots («HOT SPOTs») and possible electrical problems identified in the thermography.
• Problem identification: Processed and correlated data is used to accurately identify panels with damage, hot spots, shading or any other problems affecting system performance.
• Performance evaluation: Energy production data obtained in the field are compared with historical data and theoretical estimates. This allows to evaluate the actual performance of the system and to determine if there are significant losses or deviations from the expected performance.
• Report generation: Detailed reports are produced that include the results of the performance analysis, observations on the status of the panels and recommendations for corrective actions or improvements, if necessary.
• Post-production of images and videos: Visual and thermographic images captured during inspections undergo a post-production process to improve the quality and clarity of the visual information. This makes it easier for technicians and system owners to identify and understand problems.
• Tracking and documentation: A complete record of performance and post-production analysis results is maintained, allowing for tracking over time and comparison with future inspections.

Performance and post-production analysis is essential to obtain a detailed and accurate picture of the status of the PV panels and overall system performance. This provides valuable information to make informed decisions on system maintenance, optimization and improvement, helping to maximize solar energy production and extend the life of the panels.

In general, drone thermography is an effective technique for the technical inspection of photovoltaic panels. By using this technique, owners of solar installations can ensure that their systems are working properly and that they are generating the expected energy.