In partnership with FLIR Systems, the world’s largest supplier of thermal imaging technology, Raptor Maps recently hosted a webinar to cover the basics of inspecting solar farms with drones. With 1,500 registered viewers, we reached an unprecedented audience interested in applying this technology to detect issues and optimize asset management.

The entire webinar can be viewed below for anyone who was unable to tune in live. The following are responses to questions that were received during the webinar. Part 1, a summary of the main themes, can be found here.

Webinar Q&A

Should I make a thermal map as the solar inspection deliverable?

Raptor Maps does not recommend creating radiometric orthomosaics (thermal maps) of solar farms as the deliverable for a solar farm inspection. Thermal maps require flights at higher altitudes, resulting in a loss of detail, which is exacerbated by the blending of radiometric images. Thermal maps of solar farms are also unable to provide the detail a client needs in order to identify, classify, and localize issues. The high sidelap required means additional time spent in the field. Raptor Maps has developed its solar software solution to deliver the analytics and reports that solar companies expect from a drone inspection.

Should we take videos or photos to capture images of a solar farm?

We recommend taking infrared and high-resolution color (RGB) photos with your drone.

What flight planning strategy does Raptor Maps recommend to produce the highest quality data?

• Infrared images with a high overlap (in the direction of flight) and low sidelap (between passes).
• Color (RGB) orthomosaic flight pattern at 250–400 ft to enhance report quality. Required if no satellite image of site.

Exact altitude depends on your camera/lens setup, but a minimum 5 cm/pixel ground sampling distance (GSD) is necessary for cell-level issues. If you are using a multicopter, maintain heading at all times. Fly in a grid pattern either parallel OR perpendicular to the rows. Confirm your images contain metadata (GPS location, relative altitude, etc.) and are free from motion blur and glare.

We recommend using the flight planning app provided by the manufacturer of your drone. This FLIR forum is a great place to learn more about flight planning apps for thermal inspections, link here.

How should we angle our camera for optimal data collection?

Start with your camera pointed nadir (straight down) and tilt up to 20 degrees to avoid glare and get the best view of the modules. However, your camera should not be aligned to the modules straight-on. See this technical note to understand why.

What is the value of the Raptor Maps’ solar software solution?

Raptor Maps eliminates the time-consuming process of turning your aerial data into actionable information for solar professionals. Raptor Maps has developed Raptor Solar™, the first Artificial Intelligence (AI) software solution, to help you process thermal images, color images, and site data generated from aerial solar site inspections with drones and/or manned aircraft. The software manages the identification, classification, and localization of every solar farm issue captured in the inspection dataset.

The software analysis includes finding and classifying​:

• Major electrical issues (inverter, combiner box failure, reversed polarity)
• Defect identification at the string, module, and cell level
 (e.g., activated bypass diodes, shattered and soiled modules, etc.)
• Tracker and racking issues
• Site issues (e.g. shading, vegetation, flooding, security risks, etc.)

You can learn more about the Raptor Solar™ software here.

What is the thermal certification requirement to conduct these inspections?

There are no thermography licensing requirements required to successfully capture data for qualitative assessments of solar farms. However, it is valuable to have be familiar with thermography basics and understand the science behind these inspections. If you are interested in learning more, we recommend attending a Level 1 Thermography course and/or familiarizing yourself with the science behind aerial thermography with FLIR Delta.

How is the price determined for a solar inspection using drone technology?

There are many variables that impact the costs of performing this inspection, as well as the price that a solar company is able to pay. These variables include: size of the solar farm, the amount of work included in the project (multiple sites, multiple inspections a year, etc.), the location of the site and travel time/distance, the country/region of the drone inspection, the country/region of the solar company hiring for this service, type of client hiring for this service, etc. We strongly recommend structuring costs for this service based on the size of the solar farm and/or size of the total volume of work the client needs done.

How does Raptor Maps present a solar farm inspection report?

We offer a sample PV system inspection report here (link to be updated shortly). Raptor Maps solar software analysis delivers results through an online portal as well as standard digital and downloadable formats including .PDF, Excel, and .KML. You can also learn more about the software’s analysis capabilities here.

Are there any chance of misreadings from inspection results?

Infrared inspections capture effects such as shadowing, for example, which may appear as hotspots or damaged modules from thermal data alone. While the pattern can help to distinguish these types of effects, high-resolution color photos are an important complement to thermal imaging and will help you identify the root cause of issues, and help you avoid delivering false positives to a client. It is important to capture this imagery of the solar farm within the same timeframe/day that you inspect the site with a thermal imaging camera.

What does Raptor maps charge for software/processing?

Raptor Maps solar analysis and reporting software is priced per MWdc of site data processed. The costs include complete post-processing of infrared and color (RGB) data sets, inspection analytics, and comprehensive reports available in digital and downloadable formats. If you need a quote, please contact us here.

In partnership with FLIR Systems, the world’s largest supplier of thermal imaging technology, Raptor Maps recently hosted a webinar to cover the basics of inspecting solar farms with drones. With 1,500 registered viewers, we reached an unprecedented audience interested in applying this technology to detect issues and optimize asset management.

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. Part 2, a recap of the most frequently asked questions during the webinar, can be found here.

Commercial Drone Operations for Solar Farm Inspections

Drones are more accessible than ever before, and the market for thermal imaging is rapidly expanding. A remote pilot certificate can now be earned through a knowledge test, and the drone/camera hardware has become more integrated and user-friendly. As the photovoltaic (PV) solar industry experiences double-digit annual growth, drones have become an effective and efficient means to analyze PV assets ranging from utility-scale power plants to community and industrial installations. The majority of operations and maintenance (O&M) companies are either flying drones themselves or contracting drone services, and asset owners are also realizing the benefits.

Value of Thermal Imaging in PV System (Solar Farm) Inspections

Aerial thermal imaging detects PV system anomalies from the inverter (large) level down to the string, module (panel), and cell levels. When areas in the PV system are defective, the energy from the sun is not converted into electrical energy, resulting in an increase in temperature. Additionally, changes in the surface properties of a module manifest as a difference in emissivity, which is detected with a thermal camera. The results of aerial thermal imaging inform asset management, and save 2–5 times the labor cost in the field. Every single module is analyzed, and site condition is quantitatively tracked over time.

Planning Inspections

It is important to know the purpose of the PV system inspection and understand the level of detail a client needs prior to data collection. You should also check to see if there is satellite imagery of the PV system; if not, plan on capturing color (RGB) images to for an orthomosaic. Even if there is satellite imagery, color (RGB) images improve the quality of the report. Make sure to note the module technology (e.g., polycrystalline, CeTe), wiring (e.g., number of modules per string), and other pertinent information.

Collecting High-Quality Data

Fly on a sunny day, and avoid glare and motion blur. Take radiometric images with your thermal camera, as well as a color (RGB) dataset.We recommend high overlap (in the direction of flight). Low sidelap (between passes) is acceptable, as this will save a considerable amount of time in the field. Fly either parallel or perpendicular to the rows (not diagonally). A high-altitude site overview is helpful for detecting larger issues. Ensure your images contain metadata (GPS, altitude, timestamp, etc.). Verify your data before leaving the site.

Creating Valuable Deliverables

Raptor Solar deliverables are optimized for asset owners, performance managers, field technicians, and other solar professionals. Managers need summary statistics, grouped logically, and analysis to facilitate decision-making. Technicians need to quickly and accurately locate an identified module. Deliverables should integrate into the existing workflow. The client should be able to security share the results with their customers and within their own organization to participate in the decision-making process. Changes to the site should be quantitatively tracked over time.