In terms of labor intensity, using drones to inspect solar panels is easier than inspecting them manually. Traditional solar field assessments consist of inspecting each panel with handheld thermal imagers to check for defective cells or cables. But, the days of labor-intensive solar inspections are falling behind us thanks to drone thermography. With a drone, solar inspections are 70% faster and 40% cheaper too. Many solar asset owners are ready to get on board, but there are a few things about drone solar inspections that no one is telling you.
Solar companies need the whole truth before making the choice to integrate drones into their operations. Here at The Drone Life our team of trained drone pilots has conducted a large number of aerial thermography solar inspections. Our first-hand experience and in-depth training put us in a place to inform solar companies about what really goes into drone solar inspections. It’s a significant undertaking with many benefits, but we still think there are four major drawbacks of drone solar inspections that solar companies need to know:
Table of Contents
1. You Need Technical Training to Understand How Thermography Works
Understanding how thermography works is not an easy task. The person operating the drone and analyzing the data needs very specific skills and knowledge. Topics they should be well versed in include thermography science, flight planning, drone safety, and how to select the proper IR camera and sensor for the job.
Pilots at The Drone Life go through specialized training to obtain their Infrared Thermography Certification (ICT). ITC Certification is an expensive investment, with tuition fees for the training costing about $2,000 per person. This is a cost that solar companies are often unaware of, but the training is essential. ICT Certification is the gold standard qualification within the thermography industry and exceeds the requirements of international standards. This training qualifies our team to properly capture and interpret thermal images using a drone.
Common sUAS Thermography Vocabulary
- Qualitative & Quantitative
- Emissivity
- Gain
- Temp Span
- Auto Tune
- Thermal Tuning
- Spot Size Ratio
- Palettes
- Isotherms
- Blackbody
- Reflected Apparent Temperature
- IFOV & FOV
- Solar Absorption
- Thermal Crossover
- Thermal Shadow
- Environmental Diurnal Cycle
- Solar Reflectance
- Radiometry
- Multi-Spectral Dynamic Imaging
- Flat Field Correction
2. High-Quality Drone Equipment Costs a Lot of Money
Another drawback to drone solar inspections that solar companies are oftentimes unaware of is how much it really costs to invest in the best quality drone equipment. Before purchasing any drone equipment, companies need to determine if they’ll see a positive return on their investment. Our guide, The Ultimate ROI Guide for Infrared Drone Solar Inspections, helps companies decide if it’s worth the investment. In that guide, we estimate that the initial equipment, training, and software investment will exceed $30,000. The physical drone hardware makes up about 80% of that cost, while soft costs like training and software complete the other 20%.
The most commonly used drone for solar inspections is the DJI Matrice 300 paired with the Zenmuse H20T thermal sensor. Together, these cost about $24,500. Less expensive solutions exist such as the DJI Mavic 2 Enterprise Advanced with a built-in thermal sensor that retails for about $6,500. However, the compromise of using a cheaper infrared drone is that it will yield less accurate and less detailed results.
The pilot may try to compensate by working slower and taking more photos than typically required in order to provide an acceptable level of detail in post-processing, but the final results are still likely to be sub-par than those produced by a higher quality infrared drone system.
DJI Matrice 300
3. This is Not a Job for a Beginner Drone Pilot
Training an in-house employee to fly a drone for inspections may seem like a good idea for solar companies at first, but this is not a job for a beginner pilot. In-house drone solar inspections frequently turn out to be a terrible idea. A novice flyer with only the basic knowledge of how to operate a drone doesn’t have the knowledge or field experience needed to successfully fly an aerial thermography drone mission.
To get the best images, the pilot needs to know their camera settings. They’ll have to get the settings exactly right to ensure their images are captured at the right shooting angle, time intervals, and speed. One wrong setting can throw off all the data, and a costly re-flyover would need to happen. A qualified pilot will also understand their flight environment, from weather implications to topographic limitations. They need to know how to plan their flight’s altitude and range-to-target to get the most accurate information. And they also need to know how to navigate the legal requirements of flying a drone in controlled airspace, how to obtain airspace authorization through LAANC, and how to obtain an FAA waiver when flying in other restricted conditions.
DJI XT PRO
DJI GS PRO
With an investment in training, certifications, and a new pilot can obtain all these skills over time. However, it is easier and more economical for most solar companies to outsource their drone inspections to a professional who already has the skills and experience.
4. There’s More Work to Be Done After Flying the Drone — Interpreting the Data
Once the drone has flown the solar field and the images have been collected, there is still more work to be done. The drone’s images need to be uploaded into a post-processing software designed to analyze aerial thermography data. A misconception believed by some solar companies is that the images can be paged through one by one to detect a fault in the solar panel. However, that is not the case. In reality, the images are run through a specifically designed software that can process the thermal images and identify anomalies. Thanks to image metadata captured during the drone flight, the issues can then be geo-referenced, located, and reviewed for remediation.
Using software is much more efficient and accurate than a visual review of each separate image. At The Drone Life, we are partnered with software company RaptorMaps, the global leader in solar drone software.
Raptor Maps Image Uploading
Using their platform, we are able to detect cell anomalies, soiling, cracks, inverter anomalies, module delamination, string outages, module failures, shadowing, combiner anomalies, and more. There are fees associated with using software services, but solar companies don’t have to take this cost on themselves. Using The Drone Life, solar companies can more efficiently monitor their solar assets for a fraction of the cost.
Solution: Trust Your Drone Solar Inspections to a Qualified Professional
There is a way for solar companies to get around these drawbacks, and that is to outsource the work to a professional drone services company. Drone inspection companies like ours have already invested in the tools and training needed for aerial solar inspections so that solar companies don’t have to do it themselves. Our pilots are licensed to operate by the Federal Aviation Administration and trained in aerial thermography by the Infrared Training Center.
Solar companies that understand the drawbacks of infrared drone solar inspections prefer to hire true drone professionals who have the education, tools, and experience needed to conduct the inspections correctly. Drone solar inspections done right have resulted in an average savings of over $1,900 per MW. For more detailed information, check out our guide The Ultimate ROI Guide for Infrared Drone Solar Inspections. Weigh your options carefully, do the research, and if you have any questions reach out to us at The Drone Life.
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.
