SOLON

The solar power plant on the rooftop will transform solar energy to electric. This profitable capital investment. However, to gain a maximum yield and high power output for decades, the high-quality equipment is necessary. The solar module, the most important part of solar installation, should be reliable and capable continuously generate electricity within long years. The FLIR thermal imaging cameras allow to help to maintain its high quality throughout all service life.

One of the enterprises which estimated the high potential of technology of thermovision for quality control and check of solar modules is the German company SOLON. "We widely use the FLIR thermal imaging cameras both when carrying out research and development, and during operation" — the head of group of department of research and development of SOLON company Oliver Franck reports. The SOLON SE company founded in Berlin in 1997 is an active world supplier of solar installations. It develops the photo-electric systems and makes solar modules. Besides, design and construction of the large systems installed on roofs and also production and installation of "turnkey" solar power plants falls within the scope of its activity. The SOLON Group company has branches in Germany, Italy, France and the USA.

Acquisition of the solar module is a long-term capital investment. As a rule, solar installation pays off in 11 — 13 years depending on its price, cost of the electric power and quantity of sunlight. "Our modules are expected operation within 30 — 40 years and more — Frank adds. — Simple arithmetics shows that they will make profit for the owner within decades".

Thermovision for quality checks the Producer of solar modules should release the reliable and strong devices capable to sustain decades of operation. The SOLON company is not engaged in production of solar photo cells. It means that means are necessary for it for quality control. "SOLON positions itself as the producer of high-quality products — Frank says. — Therefore to provide compliance of our solar modules to the high standards admitted to the companies we are obliged to carry out tough quality checks for all solar photo cells and materials of the module. We check capability of materials to maintain pressure, temperature, humidity and other conditions. By search of shunts and the general quality checks of solar photo cells the FLIR thermal imaging camera plays a key role.

To detect shunts before lamination, we apply reverse bias to a unit photo cell and we create the thermal drawing using the thermal imaging camera of FLIR Systems company. Hot sections indicate the local shunts which arose in semi-conductor material of a photo cell owing to production defects. This simple check allows us to be convinced that the quality of a photo cell is at the necessary level".

The thermal imaging camera plays a key role for conducting checks Now the Berlin company SOLON uses the FLIR P65 thermal imaging camera. Frank is very happy with it: "We purchased this thermal imaging camera in 2006, and it still works perfectly. Search of shunts using thermovision is the main quality check of all new solar cells".

Now for these purposes in the market the FLIR SC660 thermal imaging camera is offered. Its uncooled detector (microbolometer) creates IK - images with the resolution of 640x480 pixels at thermal sensitivity lower than 30 mk. In the camera algorithms of automatic optimization of contrast are implemented that facilitates the thermovision analysis of objects with a large number of parts. The possibility of replacement of lenses in combination with the advanced functions of the camera does FLIR SC660 model by the ideal tool for check of solar photo cells on existence of shunts.

Thermovision under operating conditions "Success of the camera in department of research and development developed into purchase of two new FLIR thermal imaging cameras of series T for conducting checks under operating conditions — Frank continues. — They are compact, easy and ergonomic that does them by the ideal tool for similar checks". "The FLIR thermal imaging cameras excellently supplement our methods of check under operating conditions — Folker continues. — While we had no FLIR thermal imaging cameras, we had to investigate each segment manually. You can imagine, what is the time it borrows, especially on big installations. And even at detection of a problem segment we had to guess in what photo cell the defect is localized".

Instant identification of a problem "Using thermal imaging cameras from FLIR Systems company we instantly detect the defective place of the module and at once we see what the problem consists in. As origins of malfunctions in solar modules can be different, the solution of each problem requires special approach".

Hot sections on IK-images give information on the problem reason. Usually thermal anomalies demonstrate loss of power output of the considered solar module, and such high temperatures in certain cases are registered that it is possible to speak about risk for security. As a rule, such problems can be fixed. "We often come to a conclusion that the reason of a problem is in defects of connections. The quality of electrical connections can worsen over time, but usually it is easy to fix these problems".

Thermovision helps establish the reason the problem Reason also there can be a destruction of photo cells or a glass protective layer and defect of the shunting diodes. And it not everyone. "The FLIR thermal imaging cameras are the best of the tools presented at the market for detection of faults and the reasons of decrease in power output of modules — Folker explains. — It is especially relevant in the presence of the defective shunting diodes (if the defect, for example, is caused by a thunderstorm) because to reveal such problem very difficult. However defective diodes are well visible on the IK-image. The list of problems which are detected using the thermal imaging camera can be continued infinitely. By search of any problems connected with the solar module, the major stage is determination of its temperature drawing".

At the same time Folker Dentsler checks not only the module. "We visually check all installation, including cables, connectors, boxes of safety locks and inverters. Thermal imaging cameras from FLIR company is an excellent tool and for maintenance of electrical systems in general". Ergonomic construction Now all FLIR thermal imaging cameras of series T used for carrying out engineering inspections under operating conditions are equipped with the uncooled detector (microbolometer) with the resolution of 320 x 240 pixels which creates accurate IK-images at thermal sensitivity less than 50 mk. the camera fet which are specially developed for conducting checks at maintenance have the maximum operational suitability. They have compact, easy and ergonomic construction.

"The turned IR sensor is especially convenient — Folker Dentsler tells. — When checking under operating conditions we try to observe from a reverse side of the module if installation it allows. Using the turned IR sensor it is very easy to do it, and at the same time we should not creep on the ground. Thanks to ergonomic construction we can point the thermal imaging camera at the module almost at any angle".

The instant reports of the Camera FLIR of series T used by SOLON company for conducting checks under operating conditions support a number of useful functions, such as Thermal Fusion (consolidation visual and IK-images) and instant creation of the report. "We several times used the Thermal Fusion function, however function of instant creation of the report is more useful to us. At inspection of solar installation we can show at once to the user or the manager preliminary results".

Of course, the pro forma statement is followed by official. "For drawing up reports we use the software of FLIR Reporter. It allows us to adjust the level and an interval for demonstration of a significant difference of temperatures. Besides, it is compatible to Microsoft Office Word therefore we easily create reports in usual programs".

"The combination of high-quality service, excellent training and, of course, thermal imaging cameras with the quality which does not have analogs does FLIR Systems by the ideal partner for us — Folker sums up the result. — If we need to purchase the new thermal imaging camera, it, undoubtedly, again there will be a camera FLIR".