From 2010 to 2020, solar energy saw an increase of around 42% each year. The cost to buy and install solar panels decreased. Plus, tax credits helped offset some of the costs to purchase and install solar arrays. When paired with decreased electricity bills, solar is gaining ground.
There’s one problem. A solar panel cannot last forever. Most panels last no more than 30 years. Each year, the panels produce less electricity. By the time a panel is 20 years old, it’s typical to have the panel no longer producing more than 80% of the rated power. That’s why most panels only have a 20 to 25-year warranty. There’s been growing concern over what will happen as the first wave of solar panels installed in the early-2000s reach their end-of-life.
When a solar panel is no longer producing enough energy, it’s time to remove them. That leads to other issues as solar panel recycling is a relatively new industry. Solar panels are a mix of metal, plastic, and glass. Aluminum and glass make up 80% of the weight of a solar panel. Not every state has a plan in place. There is growing concern that most homeowners or business owners will simply haul their dead solar panels to the landfill.
But, they can’t just go into the landfill. They contain metals that can damage the environment. They must be removed from a roof or ground mount and brought to a recycling facility that is equipped with experts and the machines needed to recycle them. It’s a growing industry, which can make it challenging to find out where you’re supposed to bring them.
It’s a Growing Field
Recycling solar panels has been a complex issue that few states have really considered. The Federal Government classifies solar panels as hazardous waste per the Resource Conservation and Recovery Act.
Until 2021, solar panel recycling was labeled as hazardous waste in California. That made it hard to recycle materials in an economically-friendly manner. Thanks to the law change on January 1, 2021, California became the first state in the U.S. to consider solar panels as universal waste, which makes recycling easier to manage. Hopes are that other states will take similar action now that one state has taken the initiative.
As the world is relatively new to solar panel recycling, people are working on advancements in solar panel recycling technology. One innovation has been from a Japanese company that developed a machine that uses a hot blade to separate the glass from the solar cells in less than a minute.
Experts in a South Korean university came up with a way to use organic solvents that bond to the lead ions in solar cells and keep them contained. That will allow for recycling without emitting any of this damaging metal.
Two experts at an Australian university found a way to turn the recycled silicon from solar panels and reuse it to make the high-energy anodes used in lithium-ion batteries. A Swedish energy group also came up with a good use for recycled solar panel aluminum. The recycled metal can burn into a thermal energy storage system that stores solar energy for use after dark.
All of these advancements will continue to make it easier to recycle photovoltaic solar arrays. If you have them on your roof or in your backyard, learn what happens when they’re at the end of their lifecycle.
Solar Panel Recycling Takes Three Main Steps
There are three main steps involved when a company recycles a solar panel.
- The junction box and frame have to be removed from the solar panel.
- The glass and silicon wafer must be separated.
- The silicon and metals have to be separated and then the silicon is purified.
To better understand this process, it’s best to look at the construction of a solar panel from the bottom to the top.
At the very bottom is your junction box. The junction box is a mix of plastic and metal that contains the negative and positive terminals and output cables that connect to the interior diodes. This enables the series of panels to be linked together while ensuring the power keeps moving forward from one panel to the next.
The junction box is affixed to the bottom of a plastic laminated backsheet that’s often made from polyethylene terephthalate (PET) and coated with the polymer polyvinyl fluoride (PVF). That backsheet is covered in a soft, plastic film called a polymeric encapsulation that’s usually made from ethylene-vinyl acetate (EVA).
The next components are busbars. A busbar is a metal strip or bar (often aluminum or copper) that connects the solar cells, which are made from aluminum, silicon wafers, an anti-reflective layer, and a metal grid. There are several busbars connecting all of the solar cells.
On top of those components are another sheet of polymeric encapsulation, a layer of low-Fe glass, adhesive, and the aluminum frame that holds everything together. Each of these materials has to be recycled properly. If they end up in a landfill, toxic metals could end up in groundwater or soil and cause harm for future generations. Plastics take decades and even centuries to breakdown.
What Methods Are Used to Recycle the Different Materials?
To start, a mechanical process is used to remove the aluminum frame and the junction box. Once removed, they can go to shredders where the plastic and metals are separated.
Silicon has to be separated from the glass using chemicals or heat. An acid bath or high heat can help dissolve and burn up the adhesive that holds the plastic sheets and silicon wafers from the glass. Glass and plastic sheeting are then moved to shredders. After shredding, machines may use vibration to separate the heavier glass from plastic. Another method is to use a laser to identify glass from plastic.
The silicon and remaining metals that hold the solar cells together undergo chemical and electrical processing to separate the silicon from the metals. Silicon is purified so that it can be reused. Metals are shredded so that they’ll eventually get melted down and reused.
Recycling Solar Panels
When it’s time to recycle your solar panels, ERI is one of the few providers who can help.
Talk to ERI. Our recycling facilities do more than recycle electronics like personal and work computers and cellphones. Our PV Management and Solar Panel Recycling program safely recycles the different components in photovoltaic equipment and solar panels. We’ll dispatch a team of experts to recover the panels and bring them to one of our locations for recycling.
When you trust in ERI, you know all work is done in the U.S. Nothing is sent overseas. We’ll recycle your solar panels correctly and ensure that the bulk of the glass, metal, plastic, and silicon are reused to make new items and never end up in a landfill where toxic metals can harm the environment.