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February 2017

5 Visual Checks you can do before you buy a solar panel

To make sure you get your money’s worth, it is important that you buy Tier 1 solar panels. If you plan to buy unbranded solar panels from local distributors to save on cost, make sure you do these 5 visual inspections. While these will not guarantee that your solar panels will run the distance, it will at least increase your chances of getting a good buy.
Two (2) of these visual checks have to do with solar cells. Solar cells are the building blocks of solar panels. These are the 125mm x 125mm square cells that are put together to produce different types of solar panels of different power capabilities. The more solar cells, the more power a solar panel can produce. All Tier 1 solar panel manufacturers can manufacture and produce their own solar cells. So they can control the quality of their solar modules.
An estimated 90% of solar panel manufacturers however, resort to buying solar cells from third party manufacturers and then piece together and assemble the solar cells to make a solar module and solar panel. Because these solar cells come from different manufacturers, there is no certainty about its quality.
Here are the 5 visual checks:
1) Alignment of solar cells and its tabbing wire. The tabbing wire is the connection of the solar cells to each other. Solar cells are connected through by soldering the tabbing wires of adjacent solar cells. If this process is not automated, there is a big chance of misalignment. When tabbing wires are mis-aligned, there will be uneven current flow. This uneven current flow could lead to malfunction and a phenomenon known as hot spots.
2) Broken or chipped solar cells. The best solar cells are classified as Grade A. They can produce more than 90% of their rated output and have little or no micro-cracks. There are some who say that Grade B is also acceptable but Grade C is unacceptable and can lead to short term degredation. So broken or chipped cells are a sign of a lower grade solar cell which should be avoided whenever possible. For more information about the grading of solar cells, see:
3) Scratches. This is a sticky issue since solar panels are prone to scratches during handling. Small scratches have no effect on the performance of the solar panel in the beginning. However, if the scratch is big enough, it could lead to earlier than expected degredation. So if you can check the panels, get a clean and flawless one without scratches.
4) Fading serial numbers. Serial numbers are the identifying numbers we use to claim for a defective solar panel. If the serial number is faded or un-readable from the beginning, there is definitely something doubtful about the manufacturer. When we made a claim for a defective solar panel late last year in 2017, the first thing the manufacturer asked was the serial number.
5) Particles inside the solar panel. We have not encountered this but there a chance that insects or other small particles can get inside solar panel between the glass and the solar cell. If this happens it is not a good indicator for the manufacturer. The region between the glass and the solar cell should be a complete vacuum, with absolutely nothing in between.

If you want to learn more about solar panels and solar energy systems in general, we will be going to Davao on March 8. For tickets and registration, see link below:


Watch out also for an upcoming seminar in Isabela on April 8.

Image credits:
The image above was taken from a store window in Cubao. The image below with a broken solar cell was taken from Sinovoltaics, good source of information about solar for Asia.

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