Inspection of photovoltaic systems and solar systems by drone
Solar systems and photovoltaic systems are generally considered to be low-maintenance compared to comparable industrial systems . Nevertheless, it may be necessary to inspect, maintain and appraise a photovoltaic system. The drone or multicopter is a quick and inexpensive option for this inspection process. This means that regular visual inspections can be carried out quickly and easily using a thermal imaging camera . This is also the reason why drones are being used more and more to inspect photovoltaic systems. More and more specialist companies are relying on the intelligent flying robots to promptly detect damage or contamination.
Even if a photovoltaic system is generally classified as low-maintenance, it must be possible to ensure proper operation on a regular basis. To do this, the energy yields gained must be checked again and again. In particular, the values from the previous year serve as a comparison when evaluating the systems. If the yields deviate from the norm, it is very likely that there is a malfunction or a technical defect.
What faults can occur in a photovoltaic system?
Thermal damage
Mechanical damage
Contamination by dust and dirt
Weather-related cancellations
These and other influences can significantly affect a photovoltaic system or its operation. And as if that weren't enough, theft and / or vandalism can also be responsible for the fact that a regular check using a drone is considered useful.
Drone inspection : When photovoltaic and solar ground-mounted systems need to be inspected
If you want to use a drone for inspection , you can use a variety of options. The advantages differ from those of conventional forms of inspection.
Depending on the size, the assessment of a photovoltaic system including its modules can become a very expensive matter. This applies above all to photovoltaic ground-mounted systems. These are systems that were not installed on a facade or on a building. Their large area requires more effort in the inspection. Such solar parks have to be subjected to regular visual inspections, which, however, involves enormous effort. The effort relates in particular to the costs and the deployment of personnel. In order to be able to localize the existing faults, a manual visual inspection is usually required, which is combined with regular cleaning work.
Many companies have neither the technical equipment nor the staff and certainly not the necessary specialist knowledge. A drone with a thermal imaging camera offers every photovoltaic system operator as well as every maintenance company the opportunity to detect damage, dirt, vandalism and theft of individual modules at an early stage. And this in a fast and efficient way, which also proves to be cost-effective. A drone or a multicopter cannot only be equipped with optical cameras. There are also drones that have a thermal imaging camera . This allows the efficiency of a photovoltaic ground-mounted system to be optimally assessed and potential damage to be identified.
The same applies to photovoltaic systems mounted on facades or buildings. Appropriate technical equipment and trained personnel are required to carry out maintenance or visual inspections as part of an inspection on the roofs of real estate . The technical equipment not only refers to scaffolding and cherry pickers, but also to abseiling systems. A drone ensures that these outdated forms of inspection are obsolete. Drone services with a thermal imaging camera can be booked by both commercial and private operators of a photovoltaic system in order to detect contamination and damage from a safe distance. Is the visual inspection by means ofOnce the drone and thermal imaging camera have been completed, repair or cleaning work can then be carried out on the photovoltaic system.
The inspection of photovoltaic systems using drones and thermal imaging cameras is on the rise
While owners of private households are increasingly installing smaller photovoltaic systems, larger areas require significantly more square meters to be inspected. This concerns, for example:
company building
open spaces
warehouses etc.
It doesn't matter whether it's private or business: Investments are made in a photovoltaic system because it should pay off at some point. It is therefore important that photovoltaic systems that have already been installed are increasingly maintained. Thermography by drone proves to be a purely optical and non-contact measurement method. If there are temperature differences on the solar modules, these are immediately visible with a drone and thermal imaging camera . For this purpose, thermographic images are created, which serve as a first indicator of potential sources of error.
Drone inspection : why is thermography becoming increasingly important?
The photovoltaic system is to be seen as a useful contribution that is being made to the energy transition. With regard to the sustainable use of resources, photovoltaic systems are simply indispensable. And that is also the reason why their operation should run as smoothly as possible. The solar inspection using a drone and thermal imaging camera is the best test tool that can be used here. After all, large-area solar modules can be flown off in a very short time with a drone. Inspection using a drone and thermal imaging camera simply proves to be very effective as a trained eye is able to immediately communicate potential defects or loss of yield to the customer so that the appropriate action can be taken. The time-consuming construction of a truck, which is referred to as a "climber", is completely eliminated when it comes to an elevated working platform. During the drone inspection , the expert has nothing to do other than follow the inspection on the screen. In this way, he can convince himself of the reliability and functionality from a safe distance and then evaluate it.
Solar inspection by drone : what thermography can do
Regardless of whether it is for maintenance or as part of commissioning: Thermography can also be helpful when it comes to documentation. It helps to avoid yield losses and defects. Before the warranty periods expire, warranty claims can be asserted against the manufacturer by regularly carrying out documentation using drones and aerial thermography . The topic of fire protection is also becoming increasingly important. Poorly cooled or incorrectly installed electrical components can quickly cause a fire. If inverters have been installed at dizzy heights, these can also be quickly checked for possible malfunctions with a thermographic drone inspection .The thermal imaging camera ensures that temperature differences can be made visible.
Which defects are most frequently discovered in a solar system with a drone?
In the context of thermal drone inspection , certain sources of error keep popping up. Below are some examples of defects that appear again and again.
Faulty bypass diodes
Contact failure in solar cells
dirt
penetrated moisture
Short circuits in solar cells
Cracks in the module glass
Loose contact points
cracks in cells
Faulty wiring etc.
Which details have to be considered during the thermographic inspection with a drone and thermal imaging camera ?
If possible , the inspection flights for the thermographic recordings should be recorded on dry and cloud-free days. Malfunctions in the operation of a photovoltaic system can generally be created from a solar radiation of 600W/m². Conspicuous changes in the thermal properties can then be diagnosed best.
How does infrared thermography work using a drone ?
The drone pilot checks in advance whether the use of a drone with a thermal imaging camera is possible at all. The possibility relates to both legal and physical circumstances. Obtaining a flight permit is essential. This must be obtained from the operator of the solar system as well as from the owners of neighboring properties. If the solar system to be checked is near the airport or in a residential area, permission must be obtained from the aviation authority.
Inspection flight of the drone after permission has been granted
As soon as the green light has been given, the drone will be ready for use in no time. At least when an experienced drone pilot is at work. First, it flies over the system at a height of about 10 meters. This maneuver serves to get an overall impression. As soon as the first abnormalities appear, the flight altitude is reduced. The previously programmed flight route is then activated and the drone flies in the automatic route program and takes overlapping thermal aerial photos of the photovoltaic system. Anomalies in the system are analyzed in detail. Both the analysis and the evaluation of the infrared images are carried out after the inspection flight.
What are the advantages of drone inspection by an external expert?
The drone pilot is able to program the drone and keep an eye on it during the flight phase. He has been trained to fly the drone while keeping an eye on the safety of the aircraft. The expert was trained to analyze solar systems and to observe the areas to be checked in flight. As soon as the expert discovers anomalies, he provides the drone pilot with the correct instructions. He relays what needs to be done and where to fly the drone. Evaluation and analysis are the responsibility of the expert. The drone pilot takes care of flying the drone 100 percent.
What can only an expert or thermographer see in photovoltaic systems?
In order to be able to evaluate and interpret thermograms correctly, a high level of experience is required. After all, significant temperature deviations on the solar modules do not necessarily indicate a defect. It is only when an entire sub-area fails that higher performance losses are the result. However, incorrect measurements and misinterpretations happen faster than you think. For this reason, it makes sense to carry out the inspection as a duo. A well-trained drone pilot is just as essential as a correspondingly experienced expert or thermographer.
What are the advantages of a drone inspection of photovoltaic systems? The overview
Efficient and safe to use
Fast results without much effort
Live image transmission and storage of the data
Drones are immediately ready for use (also during operation)
Land and water traffic will not be affected
Staff and other people are not endangered
Liability and security risks are minimized
Various camera systems provide more flexibility
Documentation can be repeated quickly and at will