10 Common Solar Panel Defects and How to Avoid Them

10 Common Solar Panel Defects and How to Avoid Them

Talk your trusted solar panel repair specialist once you see these signs.

Solar panels are designed to generate electricity for 20 years or more – helping households and businesses reduce or even eliminate their energy bills, but the ongoing price war has led to some manufacturers cutting corners in order to remain competitive. As a result, some solar panels can start to fail before they reach their expected lifespan.

If you are wondering if your panels are fine or if they need replacing or repairing, then you’ve come to the right place. Here are 10 of the most common solar panel defects and how Aztech Solar avoids them during installation.

Hot spots

1. Hot spots

Solar cells are designed to generate electricity from exposure to sunlight. However, as electric current flows through the solar cell strings, there may be some resistance due to hot spots. Very hot days can reduce the efficiency of a solar cell.

Any imperfections such as cracks, mismatches, or poorly soldered joints can also become hot spots in the long run and lead to higher resistance. There are two long-term consequences:

  • Hot spots cause burnt marks that speed up the degradation of solar cells
  • Portions of backsheet could show through and start a fire if left unchecked.

To eliminate hot spots, reliable, skilled solar panel fitting companies like Aztech Solar check for imperfections on each solar cell before installing them. Broken cells and poorly soldered ribbons get automatically discarded.


2. Microcracks

Technological advancements in the semiconductor industry have led to wafer-thin solar cells measuring around 170 μm thick – roughly twice the diameter of human hair. Due of their super thin construction, modern cells have become more brittle and prone to microcracks which can result in hot spots and poor energy generation. Here at Aztech Solar, we take exceptional care in handling and transporting solar panels to prevent microcracks during solar installation.

Broken glass

3. Broken glass

The front glass panel of a solar module is its first line of defence against rain, hailstone, dust, tree branches, and the occasional stray ball. Therefore, it should be strong enough to withstand stress while allowing maximum absorption of sunlight.

Broken glass can make solar cells vulnerable to weather damage, and when water and dust are able to seep in under the glass, it can severely diminish the amount of light absorbed by the solar module.

To be sure, Aztech Solar only sources solar panels that have been tested against falling balls of ice and withstand the impact of hailstorms.

Dust build-up

4. Dust build-up

Dust build-up near the panel edges can significantly affect the energy production of your system. When solar panels are installed on rooftops that are flat or at a slight angle, there is a tendency for module frames to collect rainwater. As the water evaporates, dust residue is left behind and creates unwanted shade. Aztech Solar installs frames specially designed with sloping profiles and drainage channels to clear away rainwater and other debris.

Cracked cells

5. Cracked cells

The absence of robust quality control may lead to the accidental lamination of cracked solar cells into solar panels. When this happens, a mismatch is introduced to the cells, which can impact power generation. Automated production lines can screen out imperfect cells before ribbon soldering to minimise electric current resistance.

Poor string connection

6. Poor string connection

After solar cells are put together into strings, they are soldered into connected wires to complete the array inside a solar panel. When these interconnections are poorly soldered, the circuit remains open, reducing energy production by a whopping 30 per cent or more. An IR camera, which can show temperature differences among solar cell strings, can detect open circuits.

Defective junction box

7. Defective junction box

Another cause for an open circuit is a defective junction box. The junction box at the back of a solar panel is key to conducting electricity from the solar system to your home. However, if dust or moisture seeps into the junction box, it can lead to a short circuit of the diodes inside.

When the bypass diodes are burnt, they can leave the panel in an open circuit and stop transferring electricity altogether. Aztech Solar carefully selects IP67 rated junction boxes to keep dust and water from trickling into the circuits.

Snail trails

8. “Snail trails”

Even when the solar cells are broken, they can continue to generate electricity along the cracks. This, however, will cause localised heat to break down the cell surface which makes a pattern known as “Snail trails”. There may also be discoloured “snail trails” along microcracks if moisture is present. Unfortunately, apart from reducing power production, snail trails also give your panels a bad look. The best way to minimise this problem is to choose top-quality encapsulation materials that prevent water from entering the laminate.

Potential Induced Degradation (PID)

9. Potential Induced Degradation (PID)

Voltage, heat and humidity can cause PID on poor-quality solar modules, which can lead to reduced energy yield and cell damage. Solar panels are often connected in long series to produce enough voltage to drive solar inverters. However, when there is too much voltage difference between the grounded frames and solar cells, they may begin to deteriorate.

To prevent PID, solar panels go through enhanced PID tests to ensure the components do not break down under high voltage.

10. Cracked backsheets

Solar modules are exposed to temperature fluctuations every day and, when there are cracks on the backsheets, water can seep into the module laminate and damage solar cells. Here’s the bad news: according to the 2019 Global PV Reliability Report from DuPont, solar panel backsheet defects are on the rise.

The good news is that Aztech Solar uses only PV panels with backsheet materials that have been tested for damp heat and thermal cycling reliability – ensuring maximum water insulation.

Why choose Aztech Solar

With solar rebates and incentives about to end in Australia, customers are in a mad rush to install solar systems on their properties. This has resulted in some inexperienced installers cutting corners and producing precarious solar installations.

According to an NSW Fair Trading inspection, 18.5% of solar installations have major defects (122 of 658 cases). Minor defects were also spotted in 418 installations, or 63.5% of all properties inspected. Following the poor results of a safety audit conducted in Sydney, the government of New South Wales has called for further inspections of solar panels.

At Aztech Solar, our installations are all about high performance and reliability. We make sure that your investment is protected from solar panel defects – from carefully sourcing PV modules to installing the final array on your roof. Call us today on 02 4067 2643 and ask for a FREE quote or, to find out more, visit us online at aztechsolar.com.au.


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