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 M200 Series drones are a great solution as they can carry top-class thermal and RGB payloads.
- “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.
When it comes to integrating drones into your solar panel inspection workflows, DJI has a range of solutions; the best being an M200 Series UAV integrated with a DJI Zenmuse XT2 thermal sensor and a DJI Zenmuse X5S RGB camera. DJI Gold Partner Heliguy sells these and can support your enterprise drone programme.
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?
A look through the enterprise ecosystem picks out two prime candidates – the M200 Series or the Mavic 2 Enterprise Dual. And out of the two, drones in the M200 Series (V1 or V2) provide the optimal solution.
Focusing on the payloads, the XT2 is a robust dual-sensor thermal solution, with a 640 × 512 thermal resolution and a 12MP RGB camera.
According to IEC standards, you need at least a 640 x 480 thermal resolution to perform an effective thermal solar panel inspection. The XT2 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 XT2 is perfect for this.
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.
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.
An alternative to using the M200 Series and the XT2/X5S 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 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.
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.
When it comes to the DJI ecosystem, the M200 Series drones, integrated with an XT2 thermal sensor and X5S camera, offer a comprehensive and well-rounded tool for this type of inspection work.
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 programme, contact us by sending us an email or giving us a call.
James is Heliguy’s Blogger and Drone Content Executive. James keeps our readers up to date with drone news within the ever-changing industry.