Yes, solar panels break sometimes, but probably not in the way you are thinking. Most solar panels are manufactured to withstand some pretty heavy beatings from the elements, so its pretty unlikely that you would see a physically broken solar panel. In fact, SunPower panels are guaranteed to be durable enough to endure “golf-ball-sized” hail plummeting down on them and have the highest rating in durability available. When solar panels break (or lose efficiency dramatically), it’s typically caused by something invisible to the naked eye – micro cracks!
What are micro cracks and how to do they occur?
A solar panel is made up of many silicon solar cells that are all interconnected. While the panels themselves are very durable, the silicon solar cells are made of very thin wafers, usually around 0.20mm thick. Although they have some ability to flex, they can suffer from pressure/stress-induced cracks that are so small they are impossible to see with the naked eye. These are known as micro cracks and are one of the main sources of malfunctioning or even inactive cells. Micro cracks are nearly impossible to avoid and how your panels react to these cracks is very important.
Micro cracks are triggered by stress to the panel from mechanical, chemical, and natural factors such as hail, snow, sun, wind and severe cold. Further stress factors are geared towards the thermal cycles of the cells (going from hot to cold or cold to hot – very common for New Mexico’s desert climate), involving contracting, expanding and flexing metal contacts, solder and wire interconnects.
The following video from the National Renewable Energy Labratory (NREL) illustrates what these conditions can do to a solar panel over time.
What effect do micro cracks have on solar panels?
Conventional solar panels break and degrade in efficiency and power output after micro cracks occur. This is due to the way they are designed; power is moved through thin conductors on the front of each cell. If these connections are broken due to cracks, the power is unable to be moved throughout the solar panel. SunPower solar panels are designed with patented copper back plating. This allows for greater structural integrity and multiple points of contact allowing the flow of power even with a micro crack. The following video demonstrates the difference between SunPower solar panels and conventional panels.
Are micro cracks covered under the product warranty or performance warranty?
A crack in the silicon cell is a product defect and will affect the performance of the solar panel. Therefore, it is covered under the product warranty (typically 10 years for conventional solar panels). SunPower panels carry a 25-year combined product and power warranty, meaning you are fully covered for 25 years – giving you peace of mind – in the rare event that your solar panels are effected. That’s the Sunpower difference.