A big step for LED flashers in cell production

If you’re buying a flasher for cell production, you will soon have to give more thought as to whether you want the flash to be generated with a xenon lamp or with a combination of many LEDs. Hanwha Q Cells has been using an LED flasher from the start-up company Wavelabs in its production since January this year.

The decision by Hanwha Q Cells to adopt the LED flasher is notable because experts continue to voice doubts about the accuracy of LED flasher measurements compared with the established xenon flashers. The standards do not state clearly enough whether the accuracy is sufficient.

But the Wavelabs light spectrum resembles the standard sun spectrum quite closely at first glance. "We have deviations of less than 5%, calculated according to the standard," says Torsten Brammer, one of the three founders of Wavelabs Solar Metrology Systems GmbH.

The Hanwha Q Cells experts have taken a closer look and have evaluated the accuracy using spectral mismatch factors over a period of months, and are now using it regularly. The possibility of measuring not only with the entire light spectrum but also with certain sections of the spectrum is also of interest to Hanwha Q Cells experts. This allows inline diagnostics of potential production errors, they say.

Which technology gets chosen is ultimately an economic decision. A relatively large spectral mismatch factor could very well be compensated with additional calibration measures. In this respect, the success of Wavelabs does not mean that the age of the xenon flasher is over.

More on the evaluation of the Wavelabs LED flasher and an interview on the debate over xenon and LED technology with Halm, a leading manufacturer of xenon flashers, can be found on page 62 in the April issue of pv magazine.

Correction: In the print version of the article, there was an unfortunate error in the X axis of the graph representing the different light spectra. The corrected chart can be found here. The xenon spectrum is unfiltered. The flasher manufacturer uses filters to make the spectrum more similar to the standard spectrum.