Thermal Imaging For Testing Your Solar Panels

Photo taken of a panel by Accord Electrical using our advanced thermal imaging camera. You can see where the camera has picked up on a damaged hot cell.

How it works

The 320 × 240-pixel thermal detector accurately measures temperatures up to 650°C (1202°F) and produces crisp, vibrant imagery that can be enhanced with patented FLIR MSX® technology for added detail and perspective.

Ineffective solar cells

Thermal cameras are an ideal tool to check solar panels for bad cells, according to Mr. Kimpel. “If a solar cell produces less electricity, it usually produces more heat than the other cells. That means that you can very easily spot such ineffective cells with a thermal camera.” The cause for solar cell inefficiency usually lies in the uniformity of the semiconductor material that is used, for most solar panels this semi-conductor is silicon. The multi-crystalline silicon wafers used in most solar cells can be very prone to develop these non-uniformities either during the production process or later. If a solar cell has a higher concentration of these non-uniformities, it produces less electricity and more heat than others, dragging the performance of the entire panel down.

Defects

Defects may render an entire panel useless for the conversion to alternating current a certain amount of electric current is needed, so if inefficient cells drag the electricity production of the entire panel below this critical threshold the entire panel can be rendered completely useless. But there are many other possible causes for a solar panel’s performing poorly like broken cells, broken glass, water leakage, broken soldering points, defective substrings, defective bypass diodes, delamination of the semi-conductor material, defective connectors, to name just a few. Whatever the cause may be, thermal imaging cameras help the operator to find out where the cause is located and often it even indicates what the cause might be. In all the possible scenarios a thermal camera can play an important part in finding out what is wrong.

Identifying defects

“We want to prevent such defective solar panels from reaching our clients”, explains Mr. Kimpel. “And we also want to be able to monitor their performance after they are installed.” Identifying these defects requires efficient, cost-effective test and measurement methods for characterizing a cell’s performance and its electronic structure. “We invited several different suppliers to demonstrate their thermal imaging cameras and FLIR proved to have the best product for our application. We set up a test situation with an operating solar panel and we wanted to see which thermal imaging camera would spot the hot spot first

Photo taken of a panel by Accord Electrical using our advanced thermal imaging camera. You can see where the camera has picked up on water-damaged cells.