Why Do Solar Panels Lose Efficiency?
It’s an increasingly known fact that solar panels are a great way to reduce our carbon footprint. But we can’t simply install these systems and expect them to endlessly work at full capacity. Yes, it is true that, technically, there isn’t an expiration date for solar panels.
Still, as time goes by, their efficiency to convert sunlight into energy - for use in our homes or workplaces - will decrease. And, for this process, there are many causes, let’s check them out.
This may come as a surprise to you: higher temperatures are actually worse for the efficiency of solar panels. Think about ice inside a glass bottle, for example. The hotter it is, the more the ice shrinks. The same thing applies to solar panels.
In short, when photons - the particles that come from sunlight - impact the solar cells, they excite the electrons present in the equipment, eventually channelling them into electricity. If the temperature is too high, the number of electrons that are in an ‘excited state’ is bigger, which means less energy is transferred (or needed) from the photons. Hence, the panel’s efficiency to produce electricity is quite lower.
Light-Induced Degradation (LID)
When a fresh new solar panel is exposed to sunlight (in the first days or even months), its users should expect a sudden drop in the equipment’s effectiveness. This happens precisely due to the first exposure to the sun. It is a process known as “Light-Induced Degradation”, or LID. Unless you buy a second-hand panel, LID is inevitable. The positive aspect is that it generally stops after the first year of the solar cell’s use.
Potential-Induced Degradation (PID)
Imagine that the solar cells from your panels leak voltage into other elements of the modules - like the glass or the frame, for example. This is a process called “Potential-Induced Degradation”, or PID, and it can damage the panel’s capacity by more than 30%. PID can be caused by high temperatures, humidity and other environmental factors, but also by the incorrect installation of the equipment. One way you can avoid this is to choose a solar panel with inbuilt PID resistance.
Dirt and dust
The more sunlight reaches your panels, the more electricity the system can produce. This means you want to avoid every possible obstacle blocking the sun from powering the solar cells, namely trees. But don’t forget about dust either. Over time, the surface of the panels tends to accumulate layers of dirt that can also block solar energy. And, since the cells in the solar panels are connected in series, one dusty module can compromise the entire string. To avoid this, you should clean your system every once in a while.
The same is true about snow. That said, expect a drop in electricity production after a snowfall. However, it should be interesting to note that, if you decide not to clean the panels, the snow melting, after some time, can actually serve as a ‘washing’ mechanism, as it removes all the dirt in the process.
Like dirt and snow, solar shading can block the necessary sunlight from reaching your panels. This can also be quite detrimental for electricity production. On this note, you might want to consider installing your photovoltaic system away from trees and even other potential obstacles, like chimneys.
Bearing in mind all these factors, you will surely be better prepared to set up your solar system and will be able to produce all the energy for your needs. And don’t forget: every few months, make sure your panels are properly checked up. That way, you know you can go solar and be much more efficient.
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