Recently, there has been a trend of installing glass covers on both sides. Solar panels with glass protective layers on both sides are called double-glazed solar panels, glass on glass solar panels, and glass-glass solar panels. They are sometimes called double-glass solar panels. The benefits of using glass instead of opaque substrates outweigh the disadvantages of being more expensive and heavier than plastic substrates.
Double glazing only allows them to receive light from the back and front. There must be solar cells to convert the light received from the back. Although the efficiency of the rear system is not good, some manufacturers do claim that the rear efficiency is as high as 80% of the front efficiency. Double-sided solar panels do have advantages under special conditions, albeit at a certain price. Double-glazed solar panels have several advantages over standard silicon solar panels with plastic back sheets. Some of them will be discussed below.
Durability of double glass solar panels
We often see cargo cartons marked "glass, handle with care". It is generally believed that glass products are fragile. But in fact, it's not. Of course, a vessel made of glass will be very fragile in shape, but it will be very strong in sheet glass, especially if it is supported on another smooth surface. The thickness of the glass protective film on the front of our mobile phone is less than one millimeter, but it can be maintained well. The glass panels used on high-quality solar panels are suitable for withstanding an inch of hail. These hailstones can easily dent the car and may damage the windshield. But not thin panels on solar panels.
A German company claims that the front and rear sides use panels with a thickness of only 2 mm, which makes its panels no heavier than standard panels. Allegedly, the total glass thickness is less than 4 mm (2 mm on each side), and when these panels are smashed with a hammer or jumped on, they will not be damaged!
When standard types of solar panels are subjected to wind, snow or other pressure, they will bend. This tends to produce micro-cracks on the panel, thereby reducing the conversion efficiency. As claimed again, double-glazed solar panels are not easily affected.
Glass does not react with many chemicals, and certainly does not react with environmental components. This is why wine can be preserved in glass bottles for thousands of years. Since glass is non-reactive, there is no chemical reaction between the glass plate and the solar cell or epoxy resin that holds the panel together. Although the reactivity of the plastic backplane is not high, the glass is far superior.
Compared with standard solar panels, another advantage of double-glazed solar panels is reduced PID. PID is a potential cause of performance degradation. In standard solar panels, PID may reduce performance by as much as 30%. The reason is the stray currents in the module, especially those relative to ground potential. Moisture penetration and temperature will increase the effect. Since the double-glazed glass can isolate moisture from both sides, the double-glazed solar panel is actually not affected by PID.
Longer Service Life
Since the performance decline is much slower than standard solar panels, the average life span of double-glazed solar panels is longer. This means that some manufacturers can provide up to 30 years of warranty.
Bifacial solar cell modules have many advantages over traditional solar panels. Power can be generated from both sides of the double-sided module, thereby increasing the total energy production. They are generally more durable because both sides are UV resistant, and when the bifacial module is frameless, it can reduce the trouble of potentially induced degradation (PID). When more power can be generated by double-sided modules in a smaller array footprint, the cost of the system (BOS) will also be reduced.