Damp Heat Test: testing set up and purpose

The PV Damp Heat Test is an accelerated environmental aging test that determines the ability of the solar panel to withstand long-term exposure to high temperature and penetration of humidity. 

How is the Damp Heat Test performed?

The damp heat test is performed by applying 85°C ± 2°C with a relative humidity of 85% for for an uninterrupted cycle of 1,000 hours, which is well over 1 month. The to-be-tested solar panel is for this purpose placed in a damp heat test chamber in which the panel is exposed to these conditions.This test particularly challenges the lamination process of the PV module and the edge sealing from humidity. The peel strength of the PV modules that are laminated according to the traditional lamination process is decisive.[caption id="attachment_2601" align="aligncenter" width="310"] Damp Heat Test machine, source: schunk-group.com[/caption]

What problems can be found through the Damp Heat Test?

Problems that can be identified with the pv damp heat test are:

1. Corrosion
2. De-lamination
3. Junction box and module connection failures

Certification process

Damp heat testing is part of the IEC 61216 standard for crystalline solar panels, and IEC 61646 for thin film panels. Surprisingly the test is not part of the UL 1703 standard, as UL is solely focused on safety.The Damp Heat test is considered the most difficult test to pass during a certification process. It was said that over 60% of glass solar panels fail this particular test.