Drones For Solar Panel Inspections
- Drones are a powerful tool for solar panel inspections, collecting data more than 50x faster than manual methods.
- Solar panel installations have grown massively – up by 81% in 2019, compared to 2018. More installations mean more inspections.
- Harnessing the DJI ecosystem, the M300 RTK and H20T payload is a great solution, offering expanded flight time and thermal, zoom and wide-angle capabilities.
- “Drones increase data quantity and quality and reduce costs and hazardous man-hours,” says DJI.
Drones have become a vital tool for solar panel inspections, collecting data more than 50x faster than manual methods and improving safety by avoiding hazardous man-hours.
And the emergence of UAVs as the go-to tool for this type of work looks set to accelerate, as the trend towards adopting renewable energy is expected to grow massively in the coming years.
This combination offers long flight times, smart features to streamline and automate inspections, and thermal, zoom, and wide-angle capabilities – helping to increase daily productivity.
The M300 RTK has substantially improved fieldwork with its new functionalities. It has allowed us to increase daily productivity on the configuration of the plant, reaching up to 40 MWp per day of fieldwork.
Ignacio Bullon, CEO of solar panel inspection company Exanter
DJI Gold Partner Heliguy sells both the M300 RTK and M200 Series platforms, and can support your enterprise drone program throughout its lifecycle.
The benefits of using drones for solar panel inspections were explained during a webinar hosted by Eduardo Rodriguez, Enterprise Product Manager for DJI Europe.
He said: “Drones featuring thermal imaging payloads allow operators to perform a full solar farm operation in a matter of hours, compared to days using manual methods. They increase data quantity and quality and reduce costs.”
A Look At The Market
Worldwide growth of photovoltaics (also known as solar PV) has been close to exponential between 1992 and 2018. During this period of time, photovoltaics (PV) has evolved from a niche market of small scale applications to a mainstream electricity source.
And this trend is not slowing down. In fact, an 81% growth is expected in 2019 across the 28 EU countries, jumping from 11.3 GW (gigawatt) installed in 2018 to 20.4 GW in 2019.
And with these countries having until 2020 to meet their binding national renewable targets, it is predicted that there will be a large investment in the PV market and, as such, the number of installations will continue to climb.
By 2023, for instance, Germany, Spain, France, Netherlands and Italy will generate more than 75% of all European photovoltaic energy, according to statistics provided during the DJI webinar.
A photovoltaic system employs solar modules, each comprising a number of solar cells, which generate electrical power. PV installations may be ground-mounted, rooftop mounted, wall-mounted or floating. The mount may be fixed, or use a solar tracker to follow the sun across the sky.
And guess what, all of these components need to be inspected for maintenance and to ensure your operations are running smoothly.
This is where drones come in.
Drones Versus Manual Methods
Solar panel inspections are already happening, but the vast majority are still performed manually, using hand-held thermal cameras.
A thermal camera can help identify manufacturing defects, cracks, faulty inter-connectors, defective bypass diodes and temporary shadowing.
Hand-held and manual inspections are fine, but this process is not as efficient as it could be. Fly forward the drone – which yields faster and more accurate data capture and helps to improve safety.
In a nutshell, here are some of the ways that drones are a superior inspection method compared to traditional/handheld techniques:
- Increase efficiency: Drones collect data more than 50x faster than manual methods. Solar farms are typically very large installations, so a drone equipped with an appropriate thermal camera can scan the site for defects much faster than using a thermal camera on the ground.
- Get better quantity & quality information: Efficiently identify issues manual processes might miss.
- Avoid hazardous man-hours: Conduct surveys and inspections without being exposed to potential danger.
- Reduce costs: Not only in inspection, but maintenance, equipment and potential shut downs.
- Store, track & distribute data: Manage data with a secure portal and convenient reporting.
When it comes to increasing efficiency and enhancing data capture, drones have major advantages. For instance, thanks to the sophisticated payloads they can carry, drones let solar panel inspectors obtain both thermal and RGB (visible light) data.
And while thermal imaging is crucial for solar panel inspections, RGB is essential to give a complete picture of what is happening on your site.
During the webinar, Eduardo said: “With the use of drones, apart from increased efficiency and reduced costs, we can capture both thermal and RGB data and this is really, really relevant.
“By carrying out only thermal inspections, this could potentially lead to a false positive, which means we could misidentify non-electrical issues like soiling, shading or animal nesting, and you could be misled to thinking that these are electrical problems when they actually are not.”
He added: “Thermal and RGB data sets are also important when it comes to quantitative and qualitative analysis – both essential to understanding defects on solar panels.
“In terms of quantitative analysis, this refers to temperature data from every pixel on the thermal sensor. This is known as radiometric data, and this can be used to evaluate the impact of the defect.
“This is completely different from qualitative analysis. This refers to the data captured by the RGB sensor, as well as the post-analysed thermal data. It tells us which type of problem you have. It won’t tell the impact of the problem – we get that from quantitative analysis – but it will tell us if there’s an electrical problem or more of a shading/soiling problem.”
Increasing efficiency is crucial when it comes to inspecting solar panels. With weather conditions having to be almost perfect – dry, clear, little-to-no wind and the panels reaching a certain level of irradiance – there are often only a few hours in the day when checks/maintenance can be carried out. Therefore, a drone lets you capture this data quickly.
Using The DJI Eco-system
So, the case for carrying out drone inspections has been made. But which DJI aircraft is best suited for this type of work?
Out of these choices, the M300 RTK provides the optimal solution.
Solar Panel Inspection With The M300 RTK
The M300 RTK is DJI’s flagship commercial drone and it has a range of functions and capabilities which make it the perfect choice for PV inspections.
Firstly, its flight performance helps to drive efficiencies, thanks to a maximum flight time of 55 minutes without payload, or 43 minutes with the H20T.
This endurance – the longest of any DJI aircraft – ensures that more data can be collected during a single flight.
The M300 RTK is also DJI’s most robust aircraft to date, with an IP45 rating – exceeding the IP43 rating of the M200 Series V2 and V1 – and has an enhanced wind-speed resistance of 15m/s.
The drone benefits from hot-swappable batteries, enabling operators to switch them without restarting the aircraft – helping to reduce downtime.
Introducing the H20T Payload
The M300 RTK can also carry up to three payloads, has a maximum payload weight of 2.7kg, and a maximum take-off weight of 9kg.
On the payload front, the drone can be integrated with the XT2 thermal camera, Z30 zoom camera, and third-party sensors through Payload SDK.
But the real highlight of the M300 RTK is the H20 camera series, engineered especially for this drone.
For PV inspections, the H20T is an ideal solution, as it comes with zoom, thermal, and wide-angle capabilities. It also has a laser rangefinder, but that function isn’t really of use for checking solar panels.
The key specifications are:
- Thermal: 640 x 512px radiometric camera. Frame rate 30fps.
- 20MP Zoom: 23x hybrid optical zoom; 200x maximum zoom. Video resolution 4k/30fps.
- 12MP wide camera: Equivalent focal length 24mm; DFOV 82.9°.
According to IEC standards, you need at least a 640 x 480 thermal resolution to perform an effective thermal solar panel inspection. The H20T surpasses this.
The IEC also says that a 9MP camera is sufficient if you require RGB images to understand your thermal data. So again, the H20T fits the bill.
The H20T also allows operators to switch between camera views.
M300 RTK For Smart Inspection
The M300 RTK has a range of smart inspection features which streamlines and automates solar-panel inspections.
- Live Mission Recording: Record mission actions such as aircraft movement, gimbal orientation, photo shooting, and zoom level to create sample mission files for future automated inspections.
- AI Spot-Check (with the H20 Series): Automate routine inspections and capture consistent results every time. Onboard AI recognises the subject of interest and identifies it in subsequent automated missions to ensure consistent framing.
Using the M200 Series For PV Inspections
The DJI M300 RTK is DJI’s flagship enterprise drone, but if it isn’t for you, there are other options available.
While not as powerful or weather-resistant as the M300 RTK, its predecessors, the M200 Series V2, are still reliable, rugged, and capable aircraft for PV inspections.
RELATED ARTICLE: M300 RTK v M200 Series V2
Focusing on the payloads, the XT2 is a robust dual-sensor thermal solution, with a 640 × 512 thermal resolution and a 12MP RGB camera.
The XT2’s capabilities surpass the 640 x 480 thermal resolution, and 9MP RGB thresholds set out by the IEC standards for effective solar panel inspections.
However, if you need to perform more detailed RGB inspections or you want to capture more precise orthomosaics, the 12MP sensor of the XT2 is not enough.
And this is where the X5S comes in, thanks to its incredibly powerful 20.8MP RGB camera. It also has a Micro 4/3 sensor and a dynamic range of 12.8 stops.
Both payloads can be integrated with the M200 Series, however they can’t be connected at the same time on the M210/M210 RTK models as they both connect to the gimbal number one port. (The M200 drone can only carry one payload).
While this means that you will need to conduct separate flights, it still provides an efficient solution and helps you capture quality thermal and RGB data quickly and efficiently.
Mavic 2 Enterprise Dual In Solar Panel Inspections
Another alternative is the DJI Mavic 2 Enterprise Dual.
This lightweight and extremely portable solution is able to capture visible and thermal data, and is a cheaper option than the M200 Series V2 and M300 RTK, and separate payloads.
However, while its visual camera is capable of capturing 12MP images, its 160 x 120 thermal resolution is not the strongest for solar panel inspections.
It’s not to say that the Dual can’t be used for this type of work, but you would need to fly really close to your inspection site, impacting your efficiency in the process. Its limited thermal resolution could also mean that some deeper problems might be missed.
PV Checks Using The M600 Pro
Another solution to throw into the mix is the DJI M600 Pro. This heavy-duty industrial drone, which can carry large payloads, is suited to very specific missions and might not be necessary for solar panel inspections. However, this tweet below shows that it can be used for solar panel inspections – especially on very large sites.
Solar panel installations are expected to rise throughout the UK and Europe over the coming years. A jump in installations means an increase in inspections. This bodes well for the drone industry.
After all, drones are a far more effective solution than traditional, hand-held manual techniques – helping inspection firms increase efficiency, capture incredibly accurate data and enhance safety.
To find out more about the drones and payloads mentioned in this article, or to discuss how Heliguy can support, scale or start your enterprise drone program, contact us by sending us an email or giving us a call.