Solar energy is a growing field to provide clean, renewable power, Unfortunately, the current makeup of solar panels and other solar technology is not as renewable as it could be. Solar technology eventually wears out and can be difficult to recycle or dispose of once the material is spent. To address this issue, researchers and companies are creating new ways to maintain, create, and reuse new solar panels to make this technology even more beneficial for the environment.
How Solar Panels Work
Photovoltaic panels contain a number of materials, including glass, aluminum, silicon, and other microelectronic materials. When sunlight hits these materials in a solar panel, the light knocks electrons off of silicon atoms. These loose electrons flow, which creates an electrical current that can go to a grid or battery, providing electricity.
Why Panels Expire
Like any tool, solar panels get wear and tear from normal use. There are no moving parts, but chemicals can deteriorate and break down over time. Additionally, solar panels can be damaged by storms or debris. Solar panels in warmer climates may have a shorter life span since the warm temperatures cause the cells to be less efficient.
Most solar panels lose about half a percent in efficiency per year, which causes companies to have a limit on guarantees. Currently, most solar panels are guaranteed to last for a period of 20 to 30 years. Older solar panels from the 1970s and 1980s are still producing electricity, but they may not be producing as much energy as they have in the past. This means that if a panel is producing enough energy for your needs, you don’t have to buy a new one just yet, though it’s a good idea to remember the lifespan for future planning.
Recycling Solar Panels
Because many solar panels are still viable, there hasn’t been enough material and research to determine the best ways to care for an expired system. Many federal and state agencies concerned with disposing materials focus on hazardous materials that fail a toxicity/leaching test. Since most solar panels pass these tests, the panels remain unregulated.
To recycle a solar panel, it has to be separated into its different components. The metal and glass frames are removed and recycled like bottles and cans. This leaves the cells themselves, which can be treated in a number of ways. In one process, the entire panel is shredded and then crushed to fully separate the materials. Then, the materials are spun with a weak sulfuric acid and hydrogen peroxide solution in a drum for 4 to 6 hours. After that, the material is fed through several screens to separate the materials further. The materials then receive three sodium hydroxide rinses and are pressed into cakes of raw materials for use in new solar panels or other goods.
Another method removes the plastic components first by exposing the material to high temperatures. This melts the plastic components and causes others to evaporate. The evaporation also has a side benefit of powering the reactor itself. After this, the material undergoes an etching process that leaves only the glass, metal, and silicon parts. The glass and metal, like in the first process, go to existing recycling centers. The silicon then goes to a panel manufacturer as a raw material.
These are two of the more specific methods, but most other methods follow a similar process of physical breakdown, chemical rinses, and processing as raw materials. Recycling these materials may be an intense process, but the process eases the burden of extracting and creating new material, lessens the impact of conventional disposal, and creates effective products to use. Some steps of the processes carry their own drawbacks, especially the etching and thermal steps. However, there are researchers working to make these steps more sustainable and easier on the environment.
Solar Panel Recycling
Solar panels and solar cells have been a focus of sustainable energy efforts for years. Experiences have shown that these materials last a long time and are lowering in price, but they are still vulnerable to breakdowns and lessened efficiency. Companies and researchers are working to effective processes to make the materials reusable in future products. These innovations are beneficial to making a sustainable technology even more sustainable.