Solar Module Flasher (Class AAA) for Power Measurement under Standard Test Conditions (STC)

STC-Power Measurement with the Module Flasher

Unfortunately, not all solar modules show the power, which they should have according to the data sheet. To determine the real power, a solar module flasher is used.

The solar module flasher determines the power of a solar module under Standard Test Conditions (STC).

For this, a Xenon lamp produces a light flash for the duration of 20 milliseconds. The produced spectrum is the standard sun spectrum AM 1.5.
During the flash, the current/voltage curve of the solar module is measured and thus the power of the module is determined.
The flasher used in the lab has the highest class of accuracy AAA.

Electroluminescence Measurements

Results of an Electroluminescence Measurement
During production, during transport or during mounting of the solar modules an undetected damage of the modules can happen.
E.g. strong vibrations can lead to micro cracks in the solar cells. These not in any case directly cause power losses. However, over the years, these cracks get larger and severe yield losses of the plant can be the result.

If you have a suspicion regarding module damage, the electroluminescence technique is the first choice for module examination. In a dark room the module is energized by a reverse current which leads to a glowing of the solar cells. As Silicon is an indirect semiconductor, the emitted light is very poor, moreover the radiation lies in the infrared region. With specific cameras this radiation can be made visible and thus facilitates a detailed, damagefree inspection of the solar modules.


Example of a Dark-Thermography Measurement
Some solar modules have cell defects or bad contacts, e.g. because of corrosion. With Dark-Thermography these defects can be found out and documented.

For this, the solar module is energized by a strong reverse current. Inactive cell parts remain relatively cool while bad contacts can be detected by high temperatures.

Peak Power Determination On-Site

Example of the measurement of a mixture of good and bad modules
The On-Site Peak Power Method offers the possibility to measure the real power of a photovoltaic plant. With a characteristic curve measurement device a whole string of moudules can be measured.

By simultaneously measuring the irradidation and the module temperature, the string power under standard test conditions (Peak Power) can be calculated. Moreover, the course of the current/voltage curve gives information about cabling faults or quality differences of the used modules.

A large advantage of the method is the small effort: The modules must not be dismounted and the result is got relatively quickly. Disadvantages are the weather dependance and a relative large measuring tolerance of up to +/- 10 %.

Bright Thermography

The two cells at the right lower module are defective
Also on-site Bright-Thermography can be used. For this the PV plant is surveyed in normal feed-in operation with a thermography camera.

Are you interested in our offers?

Are you importer, distributor or installer of PV modules and you want to test your modules for their realy power?

Are you plant owner and you have the impression that your solar plant does not work well?

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