The flying (infra-red) eye from Saxony-Anhalt

A successful test flight

Markus Köhler started his business venture in January 2014. His idea originated in his original professional field - the property sector. Part of his work involved taking photos of buildings - including from the air - to present them in brochures. He originally worked with a 15-metre-high tripod before starting to use cameras attached to drones.

Using the drones, he started thinking about other areas of industry in which this technology could be put to good use. The answer: checking and detecting photovoltaic systems with infra-red technology. What followed were several tests, the development of the drones for their new purpose, the completion of many test flights, the creation of an effective reporting method in cooperation with the customers - and the necessity to overcome quite a few challenges and setbacks along the way. They weren't enough to throw the enthusiastic hobby drone pilot off course, however.

"In Europe alone, the market potential is currently estimated to be around 180 gigawatt peak. The area of business remains relatively undeveloped. And nothing that I'm doing is really that difficult. It is more the many high detail, technical improvements, our highly regarded reporting, the care that we apply, as well as our precision and our specialisation on high volume business that make our service special," explains Köhler.

When he or one of his pilots completes one of their projects - which could be anywhere in Europe - the customer is often surprised with the assessment they receive at the end of the flight. After all, the infra-red eye of the drone sees everything. During the slow reconnaissance flight, the smallest discrepancies in temperature are detected, allowing conclusions to be drawn about defects in the modules. Every defect means a loss in earnings - and the loss depends on the type of fault and its frequency. If the image shows that a complete row of solar panels isn't working for instance, the customer can be very angry because they have been relying on their monitoring system, that has failed to reveal it.

"Sometimes we uncover problems with the inverters, sometimes it's defective fuses, and sometimes broken cables." These are joined by cell breakages, frequent cases of individual modules running idle and so-called sub-string diode problems. The operators often ask Markus Köhler to fly over their systems to check out warranty-related issues regarding their solar systems. Köhler also frequently encounters the big topic of the PID effect, or "potential induced degradation" - the successive decline in the modules' voltages which spreads like a virus - during his work. Many of these defects go unnoticed by the built-in monitoring systems. Quite deliberately, Köhler doesn't use the word 'faults', but rather, 'anomalies'. At the end of their order, every customer gets a detailed listing of the anomalies that have been revealed on the modules in question. They also include the corresponding photos - but these can only be deciphered by experts like Köhler, even though he isn't one to go in for overly detailed, jargon-based evaluations. "On some of the photos I can see the fault or the cause of the problem immediately. Apart from a glass breakage, none of them can be identified with the naked eye," explains Markus Köhler.

A start-up at 56

Although the smart gentleman with the suit and tie would appear to have little in common with the typical young and trendy executives of today, the entrepreneur was nonetheless eager to try something new. His business model is customised to his customer's requirements.

"At 56, I have a lot of business experience that many young entrepreneurs simply do not have. Thanks to my property company I've got a stable business background which enabled me to take this step, and has so far provided all the funding for my investments," explains Köhler. Although the infra-red drones are yet to deliver any profits, this is set to change. Making money with just one drone, however, isn't feasible. The company therefore has ten drones equipped with infra-red cameras, 15 pilots and 16 assessors.

"The only incalculable risk is the weather. The drones have to fly in sunlight (at least 700 W/m²) to be able to check the collectors properly. Our latest generation drones can cope with wind speeds of up to force 7. In central Europe, this means that there are only around 60 to 80 days per year on which the reconnaissance flights are possible. This, of course, means that the service we are offering has a high commercial risk."

The subtle difference

"It is neither the drones nor the camera technology that are the special things. It is our combination of many small and succinct details which make us stand out from our competitors," explains Köhler, with more than just a little pride. The drones have been designed especially for their use. Then there is the system of evaluation that we ourselves have configured which summarises the data in one file and which allows the customer to link every anomaly with the right part of the module.

Köhler doesn't want to reveal the secret to exactly how it works. His list of customers has developed very well. He now completes flights for the TÜV, which uses the Flying Inspection Service and the infra-red drones in its certification work. He also has customers in Great Britain, Spain and Italy. The drones usually fly over outdoor installations - a 20 megawatt facility being the biggest to have been surveyed so far - as well as large roof installations.

Markus Köhler has also been considering the future of his start-up, and he plans to present his latest brainchild at the Intersolar 2016: the surveying of photovoltaic systems by manned aircraft. "The added costs of this system can be covered by its huge gains in efficiency! You can't stand still if you want to keep up with the customers' needs, which get more and more sophisticated all the time," says Markus Köhler.

Koehler's Flying Inspection Service is also collaborating with the Fraunhofer Centre for Silicon Photovoltaic CSP in Halle/Saale, Saxony-Anhalt, and collates statistical data regarding faults and failures affecting solar installations. With the Fraunhofer Institute in Braunschweig, a project is being conceptualised for testing the drone technology to assess its suitability for inspecting the rotary blades on wind power turbines.