Why do Solar Panels Degrade Over the Time?
All solar panels slowly gradually degrade. This is because most solar power systems have production guarantees that get shorter over time. Generally, solar modules can experience an annual solar panel degradation rate of about 0.5% to 3%.
We will discuss the Factors that Contribute to Normal Degradation and why solar panels degrade Over time.
What is Solar Degradation?
The process in which efficiency of solar panels power production decreases over time is called degradation. According to NREL study, average solar panels lose about 0.5% of their value every year. However, the degradation rate could be higher, from 0.5% to 3% in hotter places and for residential solar systems that install solar panels on your roof.
If the decline rate is 0.5%, it means that the power output of a solar panel will go down by 0.5% every year. This means that the module makes about 90% of the electricity it did in year 1 in 20 years.
Factors that Contribute to Normal Degradation
There are four primary contributors to this natural degradation stemming from environmental factors: thermal cycling, damp heat, humidity freeze, and ultraviolet (UV) exposure.
Thermal cycling: Weather conditions that are very hot or very cold affect the soldered links inside the panel.
Damp heat: Prolonged exposure to high humidity at elevated temperatures can lead to the separation of the material insulating the cells.
Humidity freeze: Occurring when high humidity suddenly freezes can affect the adhesion of the junction box.
UV exposure: The backsheet (the side of the panel facing away from the sun) can become discoloured and worn down from exposure to the sun’s ultraviolet rays. The back sheet keeps photovoltaic cells and electrical parts safe from outside forces and electricity from flowing.
Another factor influencing degradation in solar arrays is the busbars, wires across solar cells that transport electrons. Paradoxically, the more busbars present in a module, the more efficient it becomes.
Busbars are usually soldered to the solar cell to connect them. Those soldering places put stress on the solar cell, which can cause tiny cracks to form. If you have a lot of small busbars, the bonding points will be more minor, which may make that part of the cell less stressed.
If you think your solar panels are broken or not working right, you should call the company that put them up or the company with a repair plan. Sometimes, the problem is easy to fix, like when a solar professional cleans it.
Causes solar panel degradation
Solar panels usually come with a 25- to 30-year warranty that will last, but their performance decreases over time. So, by the time they hit 30 years, they won’t be as valuable as they were on the first day.
Solar panels are a green way to get power, but many things can change how well they work over time. Here are the leading causes of solar panel degradation, giving you information backed by studies, polls, and sources. This knowledge aims to empower you to make informed decisions for the sustained performance of your solar energy system.
Natural Aging:
Solar panels experience a natural aging process over time, as with any technology. The National Renewable Energy Laboratory (NREL) has performed research that indicates frequent maintenance can lessen the influence of this aging process. These findings highlight the significance of long-term considerations for optimal panel performance. These findings highlight the importance of long-term considerations for optimal panel performance.
External Factors:
External elements, including thermal cycling, damp heat, humidity freeze, and UV exposure, play a crucial role in solar panel degradation. NREL’s 2015 survey of New York installers highlighted the prevalence of issues caused by these external factors. This underscores the necessity of selecting panels designed to withstand specific climate conditions, emphasizing regional considerations in solar panel choices.
Potential Induced Degradation (PID):
The increasing use of transformerless inverters in U.S. solar projects introduces potential induced degradation (PID) as a concern. Researchers have found that electrical current can leak from transformerless inverters that are not grounded. This can cause sodium ions to move around, making the panel work less well. Careful inverter selection and proper grounding during solar installation are vital preventive measures.
Reduced Material Quality:
Cost-cutting measures implemented by some solar panel manufacturers can result in thinner frames and lower-quality materials. Research by NREL suggests that thinner frames may bend under stress, affecting the overall integrity of the solar panel. Investing in panels with robust frames and high-quality materials becomes imperative to ensure prolonged efficiency.
Thinner Busbars:
The industry’s inclination towards thinner busbars can impact solder bond failures. While it may increase the failure results, this approach reduces stress on individual cells simultaneously. Keeping the general structure’s integrity requires finding a balance between these factors. [Reference: Industry Trends Report on Busbar Design].
Flexible Panels and Installation:
With the goal of cost reduction, module companies are introducing ultra-thin, flexible solar cells. However, these panels are more susceptible to microcracks during installation. Studies show that careful handling during transport and installation is very important to avoid unneeded stress and possible microcracks over time. [Reference: NREL Flexible Panels Study].
By learning about all the different causes of solar panel degradation, customers can make smart choices about which systems to buy, how to put them, and how to keep them in good shape.
Using best practices and choosing reliable parts based on research and poll results will ensure that solar panels last for years and continue to work well.
What Can We Do?
Not every new technology poses risks, and not all modules are prone to failure. NREL research indicates a decrease in reported PV module issues. While the nature of problems may evolve, there’s a positive trend with increasing module warranties and longer system lifespans.
Prudent purchasing and careful installation of solar panels and associated components can minimize the likelihood of degradation. If you choose well-known brands and place them carefully, you can be sure that they will work perfectly and lose at most 3% of their power each year.
What is Light Induced Degradation (LID)?
Photovoltaic (PV) modules experience a reduction in performance during the first few hours of sunshine exposure, known as Light-Induced Degradation (LID). It mainly affects how installed modules perform compared to the specs listed on the nameplate that specific PV module suppliers supply.
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