05.03.1917 / Blog, Blog
Defects in modules at solar farms can be reliably identified using thermographic cameras.
Over the next two years, juwi Operations & Maintenance GmbH will inspect solar farms with a total rating of about 285 MW for operator CEE using thermographic cameras. juwi operations expert Maik Lojewski explains why this type of inspection is crucially important for solar module troubleshooting:
Thermography can identify defects which are not evident in normal monitoring: faulty cells, faulty diodes, hotspots, broken glass, module strings out of action. For example, the output of a module with a faulty diode may be reduced by about 33 percent. If you assume that about 10 modules per megawatt are faulty in the case of ground-mounted system, the total reduction in output soon mounts up.
In addition, solar farm operators who inspect their modules with the thermographic camera can submit complaints about defects to the manufacturer. Thermography can also identify recurrent manufacturing errors of the type which have occurred with almost all manufacturers so that complaints can be submitted. In comparison, the cost of this very precise type of troubleshooting is very reasonable; you can normally expect a cost of about €1,000 per megawatt. Considering that there are about 10 faulty modules per megawatt and each module has a value of about €250, the cost/benefit analysis is quite simple.
It is also important to note that this approach can be used for virtually all types of modules. However, in the case of thin film modules, other service providers only have very limited experience. In this area, we certainly have an exceptional position together with our partner HaWe Engineering: juwi and HaWe have already inspected many megawatts of First Solar thin-film modules successfully using a thermographic camera. Modules with a suspicious image in the thermogram are checked by characteristic curve measurements and “flashing” to confirm the results. This way, we can clearly say whether a module has significantly reduced output on the basis of the thermograms. We have a better command of this approach than any other service provider.
I am convinced that annual thermographic inspection of solar parks would be a profitable investment for any operator. At any rate, our service has been very well received and many operators have already opted for annual inspection.