Despite the need for a long-lasting, reliable solar system, we still see many solar panel brands competing almost exclusively on price. In practice, as some brands skimp on product quality to remain price-competitive, solar panels begin to fail before their expected lifetime is reached. Here are 11 of the most common solar panel failures to look out for in a solar installation and how WINAICO works to prevent them in your installation.
HOT SPOTS ACCELERATE THE DEGRADATION OF SOLAR CELLS
Solar cells are designed to generate electricity when exposed to sunlight.
As current flows through the solar cell strings in the modules, the resistance in the cells converts the current into heat losses.
Any imperfections in solar cells such as cracks, poor solder joints, and mismatches will result in higher resistance and eventually become hot spots.
The long-term effects of hot spots include burn marks that degrade solar cells and back sheets, eventually leading to fires if left unchecked.
To eliminate hot spots in the field, WINAICO uses automated production processes to sort out defective solar cells before they are connected.
This ensures that WINAICO does not ship broken cells and badly soldered solder bands.
MICROCRACKS ON SOLAR CELLS REDUCE ENERGY PRODUCTION
Advances in semiconductor processing have resulted in wafer-thin solar cells about 170 μm thick, about twice the diameter of a human hair.
This leads to extremely brittle solar cells that are prone to cracking from any force.
When microcracks form in a solar panel, the affected solar cells have difficulty conducting electrical currents, resulting in poor energy production and hot spots.
WINAICO uses the electroluminescence inspection process, which acts like an X-ray machine for modules, to ensure that no microcracks occur during solar module production.
In addition, our expert installation partners exercise the necessary care when transporting and handling solar modules, thus ensuring error-free installation.
BROKEN GLASS MAKES SOLAR CELLS MORE SUSCEPTIBLE TO WEATHER DAMAGE
The front glass pane of a solar module is the first line of defense against the elements such as rain, dust, hail, and the occasional stray golf ball.
An ideal glass should be strong enough to withstand reasonable loads such as hail while still allowing as much sunlight as possible to penetrate the solar cells.
When glass is damaged, not only does light transmission decrease, but foreign elements such as water and dust can get under the glass, shadowing the solar cells and affecting energy output.
WINAICO chooses reinforced solar glass materials that strike a balance between weight and strength to ensure our modules are reliable while being easy to handle.
Our module glass is tested against 35mm thick balls of ice traveling at 100km/h to ensure it can withstand a hailstorm.
The anti-reflective coating on the glass also maximizes the amount of light that reaches the solar cells for the best yields.
DUST ACCUMULATIONS NEAR MODULE EDGES CAN SHADE SOLAR CELLS
When solar panels are mounted on roofs with a shallow pitch, rainwater often collects in the panel frames.
When the water evaporates, dust residue is left behind and creates an unwanted shadow that reduces the module’s energy production.
WINAICO’s unique frames are specially designed with sloping profiles and drainage channels to facilitate water drainage from the surface and remove dust and dirt.
CRACKED SOLAR CELLS ARE A SIGN OF POOR PRODUCTION QUALITY
Not all solar panel production lines are created equal.
If there is a bad production line, cracked solar cells will also be laminated into solar modules, leading to a mismatch of the cells and reduced electricity production.
In WINAICO’s production line, the sorting and stringing process is automated.
To minimize the line resistance, defective cells are sorted out before soldering.
After the solar cells have been connected to 6 strings of 10 cells each, they are connected and soldered to a 6×10 array within a module.
We have seen solar panels with poorly soldered connections resulting in 1/3 of the solar cells being open circuit, reducing the panel’s energy production by 1/3 or more.
The open-circuit can be detected with an IR camera as there is a significant temperature difference between the solar cell strings.
This error can be prevented through finely tuned manufacturing techniques and careful EL inspection.
A DEFECTIVE JUNCTION BOX CAN RESULT IN AN OPEN CIRCUIT
A junction box on the back of a solar module is the most important interface for conducting electricity to the outside.
If water or dust gets into the junction box body, the bypass diodes inside can short circuit and burn out.
A burned bypass diode or connector can leave the panel in an open circuit and completely cut off the transfer of power to the outside.
WINAICO carefully selects IP67 rated junction boxes that prevent dust and water ingress and protect the electrical circuits.
SLUG TRACKS CAN BE SIGNS OF MICROCRACKS
When solar cells are cracked, the cells continue to generate electricity along the cracks, the resulting localized heat can degrade the cell surface and EVA.
If water vapor is also present, discolored snail trails form along the microcracks, which not only reduce energy production but also spoil the appearance.
The best way to reduce slug tracks in solar panels is to choose reliable encapsulation materials to prevent water vapor from penetrating the laminate and to treat the panels carefully to prevent the formation of microcracks.
PID DEGRADATION DAMAGES SOLAR CELLS AND REDUCES ENERGY OUTPUT
Solar panels are typically connected in long series to generate high system voltage, sometimes as high as 1000V, to drive solar inverters.
The high voltage difference between the grounded frames and the solar cells may be too great for inferior quality solar cells and the degradation begins to worsen.