3 Common Solar Module Quality Issues to Understand & Act On

482 views

Published on

The article explains about the cause & effect of Potential Induced Degradation, Snail Trail & Long Time Damp Heat as quality issues in solar PV modules.

Published in: Science
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
482
On SlideShare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
22
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

3 Common Solar Module Quality Issues to Understand & Act On

  1. 1.       3  Common  Solar  Module  Quality  Issues  to  Understand  &   Act  On     Potential Induced Degradation - Potential Induced Degradation (PID) occurs when the module’s voltage potential and leakage current drive ion mobility within the module between the semiconductor material and other elements of the module (e.g. glass, mount and frame), thus causing the module’s power output capacity to degrade. The ion mobility accelerates with humidity, temperature and voltage potential. To bring down the effect caused by PID, manufacturers need to improve the insulation of EVA and refractive index of silicon nitride layer of solar cell. Some suppliers ignore PID-free demand of solar cell, and partially pursue module’s high efficiency. Snail Trail - Snail Trail is caused by solar cell grid discolour and till now the mechanism is still unknown. Main reason is that moisture transmits through the back sheet, EVA and solar cell, and reacts with silver on cell grid and EVA. Choosing the back sheet with low moisture transmission could prevent Snail Trail. Also, the back sheet will turn yellow if the front EVA lets UV transmit. We should strictly control light transmission in EVA selection. Long Time Damp Heat - Solar panel power output will degrade after long-time damp heat (DH). After DH, heat spots might appear in the corresponding position of cell back-electrode in short-circuit condition, which can even cause 70% power degradation. Manufacturers ignore the importance of back electrode, to lower cost at the expense of using little silver. In current IEC standard, module power degradation must be less than 10% after module is subjected to long time damp heat of 1000 Hours.  

×