Raptor Maps partnered with RMUS on a webinar to cover the specifics of using drones for the inspection of PV systems (solar farms) with both infrared and high-resolution cameras. The goal of the webinar was to break down how to set up a drone flight (equipment and flight app), how to collect the best data, and an overview of what types of deliverables are most valuable to companies involved in building, owning, and managing these sites.

The entire webinar can be viewed below for anyone who was unable to tune in live. The following is a summary of the central themes discussed in the webinar.

How to Fly and Inspect a Solar Farm with a Drone and Infrared Camera

To minimize the time you spend in the field and the amount of data you have to collect and transfer, it is critical to perform a few practice flights as soon as you purchase your hardware. Familiarizing yourself with how to set up the hardware and how to set up a mission (flights) doesn’t have to be done at a solar farm. We also strongly recommend practicing how to map out both a thermal imaging inspection and a high-resolution imaging inspection.

Ideally, PV inspections should be performed on sunny days with minimal wind and cloud coverage. Less than 25% cloud coverage is ideal. Also, flying in the morning or late afternoon can help avoid issues with glare from the panels, which impacts image quality.

In order to ensure there is no motion blur, you should not fly over 7 mph (3m/s). The flight should be parallel along the solar rows, with 80% overlap (frontlap) in the direction of flight and 20% overlap (sidelap) between passes. We have seen that pointing the camera perpendicular to the flight path (in the direction the solar panels are facing) can result in better data quality as well and quicker processing turnaround time.

Why You Should Also Do a High-Resolution Color Imaging Drone Inspection

Raptor Maps recommends performing two flights as part of the data collection. One primary inspection using a radiometric infrared (thermal) imaging camera, ie. DJI FLIR Zenmuse XT 640x512 30Hz 13mm Lens, and a second inspection using a high-resolution (RGB) color imaging camera, ie. DJI Zenmuse X3.

A thermal imaging camera will allow you to identify issues that cannot be seen with the naked eye and are impacting production of the site. Certain defects found in thermal imagery need to be double-checked against high-resolution images, such as shattering or soiling, to determine the root cause of the anomaly. High-resolution images also capture a higher-level of detail, enabling additional reporting on a PV system. This data can be used to identify potential warranty related issues like delamination and/or create an RGB map of a solar farm with no current satellite imagery available for use as a base-layer in an inspection report.

Why You Should be Delivering a PV System Inspection Report to Your Client and NOT Just a Thermal Map of the Solar Farm

A radiometric orthomosaic (thermal map) is a high-level representation of an area of land that has been captured with a thermal camera and the images have been stitched together. After dozens of meetings with solar companies we have learned that a thermal map is NOT a complete deliverable.

The high altitude solar inspections have to be performed at to produce thermal maps cause you to lose large amounts of image detail and false positives or stitching artifacts are often created. Thermal maps also require at least 4X the number of images to be captured for a map to be created vs an inspection that results in the creation of an image based report. This means a lot more time on site flying and everything involved in long flight time.

In contrast, a report created using the individual thermal and high-resolution imagery allows you deliver more detailed information to the client. Reports generated with Raptor Maps also require much less data to be captured, ie. less overlap, and less time flying a site so you can fly more sites in a day/week.

How Raptor Maps Has Made it Easy for Anyone to Turn Your Raw Solar Farm Inspection Data into a High-Quality PV System Inspection Report

Once you have finished flying both the infrared and high-resolution imaging missions, you most likely have a few thousand photos to analyze before you can create a valuable report. Raptor Maps believes your time is better spent flying more sites or performing other valuable tasks instead of reviewing the large volume of images you’ve captured and then building a report.

We have built software that automates the identification, classification, and localization of anomalies from the drone imagery. The software is able to process the inspection data using AI and machine learning and is able to analyze both thermal and high-resolution color imagery of solar farms from 100 kWp to 300+ MWp.

Raptor Maps software also automatically produces a PV system inspection report with the analytics generated during data review. These reports are suited for performance managers, asset owners, and field technicians. Every identified anomaly is classified by type and localized within the site and assigned coordinates, enabling technicians to quickly visit each anomaly in the field. The primary report also includes site information, details about the actual inspection, and a defect analysis. This is valuable for asset management, as it isolates areas with the most loss and identifies the root causes.

PV inspection reports produced by Raptor Maps are integrated into a clients workflow through an interactive portal which is accessible to third parties, so clients can share with their own clients how the asset is performing. Reports also allow you to track changes over time and compare sites across portfolios, enabling better decisions concerning solar farms over different regions. Raptor Maps software allows asset owners and O&M managers to spend less time reviewing data, allocate less capital towards labor, and grow their portfolios.