Solar panels are an extremely effective way of powering your home and appliances. However, people worry about whether storing away their panels would make them lose their efficiency, particularly if they need to move away or are using them to power their vacation home. So, do solar panels degrade when not in use?
Solar panels do not degrade when they are not in use. However, they do degrade at an average rate of about 1% a year at a minimum. Additionally, your panels will degrade as a result of regular wear and tear and even sun exposure.
While your panels will not degrade simply as a result of disuse, there are several other reasons they will degrade. To learn more about solar panel degradation, keep reading.
Solar Panels Degrade Naturally in Performance Over Time
Regardless of whether or not you use your panels, how you use your panels, and how well you maintain your solar panels, they will degrade over time.
Specifically, they degrade by 0.5%-3% a year, with an average degradation of about 1%. Most of the reasons for this degradation can be attributed to sunlight exposure, so it can be argued that your panels will degrade less or even less if they’re carefully stored out of direct sunlight.
However, another major reason for solar panel degradation is humidity. So, unless your panels are packed extremely carefully and exposed to no humidity whatsoever (which is extremely challenging to do), your panels will continue to degrade over time. Furthermore, some degradation happens as a result of general aging.
Reasons for Solar Panel Degradation
As mentioned above, there are several reasons your solar panels can degrade. These include:
Microcracks
Your solar panels will naturally develop microcracks as soon as you start using them.
When exposed to normal weather conditions, solar panels will undergo the thermal cycling process. This is to say, they’ll get hot and expand in the summer and get cold and contract in the winter.
This process is natural and cannot be avoided if you plan on using solar panels. It also causes microcracks–cracks too small to be seen by the naked eye–to develop along the silicon of your panels.
Though these cracks are often invisible to us, they can cause the soldered electrical connections in your panels to collapse.
This reduces the paths available for the electrons to travel along the panel and into your solar battery/appliances, resulting in lower electricity output from your panels.
Sun Exposure
Though it may seem counterintuitive, your solar panels can actually get too hot to work efficiently. Specifically, they stop being as effective at temperatures over 95°F (35°C).
However, the surface temperature of the panels can get significantly hotter than this limit, causing your panels to stop working as efficiently.
When exposed to sunlight, your solar panels can actually start to discolor, turning brown and yellow from the original black.
This is also known as ethyl vinyl acetate (EVA) browning. EVA browning may also occur due to the formation of acetic acid, which happens as a result of the chemicals involved in creating solar panels.
Discoloration also significantly affects the performance of your panels. This is because the change in color prevents them from absorbing as much sunlight as they would in ideal conditions.
Light-Induced Degradation (LID)
As the name implies, LID occurs as soon as your solar panels are exposed to sunlight. This is different from the impact of high temperatures since sunlight at any temperature can cause LID.
This is because exposure to sunlight also means exposure to solar radiation. This exposure negatively affects the photoconductivity of your panels.
LID is not an ongoing issue–it occurs during the first 1,000 hours of using your panels, after which your panels “adjust” to the solar radiation.
During this period, your panels will lose anywhere from 1-3% effectiveness before stabilizing.
There are several versions of LID, including:
- UV LID. Happens when your solar panels are exposed to UV radiation, which causes the silicon oxide crystals on your panel to convert to boron dioxide. This coating of boron dioxide affects the panels’ ability to absorb sunlight.
- Direct LID. This happens when you’re initially setting up your solar panels, providing them with what is possibly their first exposure to direct sunlight. When exposed to direct sunlight, the connections within the panels can warp and buckle as a result of both light and heat exposure.
Humidity
Aside from light, humidity is one of the primary causes of degradation in solar panels. Specifically, if your solar panels are stored or used in locations where there is high humidity, your panels’ junction box adhesion can be affected.
This is one issue that your panels may face even while in storage because if the storage area is humid, they’ll continue to degrade even when they aren’t in use.
Potential Induced Degradation (PID)
While most of the other forms of degradation will happen to most, if not all, solar panels, this isn’t the case with PID.
PID does not occur in all panels. However, if it does happen, it can be extremely damaging to your panels, negatively affecting their functioning by as much as 30-80%.
This form of solar panel degradation occurs when the different parts of your panel work at different voltages. This is especially common when multiple panels are connected together.
When the different parts in the panels are at different voltages, this increases the risk of voltage leaks. It is these voltage leaks that cause damage and degradation to your solar panels.
Final Thoughts
Your solar panels will not degrade when they aren’t being used. In fact, it can be argued that it is panel use that causes degradation.
However, you must also consider age-related degradation, which happens whether or not your panels are in use.
While solar panels degrade naturally, you can slow down this degradation by investing in high-quality solar panels and ensuring your panels are assembled correctly.
If you’re not confident about your solar panel assembly skills, it’s best to hire a professional–doing so is much cheaper than having to replace your panels because of a mistake during assembly.
