The following series breaks down the three most common levels of aerial thermography inspections used by Raptor Maps to identify defects, faults, and anomalies affecting PV system performance. The inspections; Overview, Standard, and Comprehensive, differ in flight altitude, data capture time, level of analysis, and the level of detail in the final deliverables. While aerial thermography is often the most efficient method to inspect a solar PV system for performance issues, understanding the level of inspection you need will enable you to maximize ROI. In this article, we will go over parameters, use cases, and the pros and cons of Overview Aerial Inspections.
Of the three types of UAV inspections, an Overview inspection is flown at the highest altitude, providing infrared thermal imagery at a 10-15 cm/px resolution and high-definition color imagery at a 5 cm/px resolution. These inspections are performed very quickly, due to a maximum flight speed of 30 MPH (48 KMH). Combined, the high altitude and speed allow for very large sites to be inspected quickly.
Overview aerial thermography inspections should be used to identify larger-scale anomalies with a significant impact on PV system performance. Particularly in the case of large scale PV systems (20 MW or more), and multiple smaller PV systems that are grouped together in the same geographic area. An overview inspection is the most economical solution to identify major faults and anomalies that will warrant a field visit and repairs. The thermal infrared and high-definition (HD) color image resolutions of this inspection enables the accurate identification of module, string, inverter, combiner, and other large scale anomalies. These high-impact anomalies cause a large loss in annual production and revenue and are the highest priority to resolve.
The main drawback to an overview aerial inspection is the limited image resolution and limit of what module and sub-module level anomalies can be correctly identified. The resolution of the data is low due to the current limitations of IR sensors. The level of detail in the HD color images is also low and has limits on what can be identified. This increases the chance of having a false positive for sub-module level faults, including diode and cell anomalies. Sub-module inspections require a higher image resolution and a lower flight altitude. Due to these drawbacks, absolute temperature accuracy is not available for Oviewview inspections.
Industry Use Cases:
In the PV industry, Overview inspections have been used when teams are more focused on finding anomalies that have the highest power loss impact on their PV system. Teams then use the data to properly allocate resources on which PV systems or sections of PV systems need to be more thoroughly inspected. The overview inspection is widely applied by teams managing PV systems looking to quickly gauge the operating health and production.
To close, an overview aerial thermography inspection will quickly and cost-effectively identify high impact anomalies, providing data on where further inspection should be focused. The speed and altitude make it efficient and economical to inspect PV systems of various sizes and densities. Though fast, they lack the detail to confidently identify sub-module level anomalies and can produce false-positives. Overall, these inspections are a good option for teams looking to quickly assess the health of a PV system and identify areas that need a more granular diagnosis.
If you would like to learn more about how using drones and software can support solar inspections for solar PV systems please contact us HERE or email us directly through firstname.lastname@example.org. We can also help you learn more about our software that converts your inspection imagery into final reports that are accurate and easy to use for asset management and maintenance.