The next recycling boom: silver and co from solar panels

The next recycling boom: silver and other materials from solar panels Solar panels are designed to last decades, yet more and more are set to be replaced soon, becoming potential sources of raw materials. Since the early 2000s, around 1.5 million modules were installed worldwide each year, primarily in Germany and Japan. Today, there are approximately eight billion solar modules globally, with over three terawatts of capacity, and the expansion continues to accelerate. Many older installations are approaching their end of life, though sufficient recycling facilities remain lacking to meet the upcoming demand. Solar panels can endure for several decades. After 30 years, most still produce around 85 percent of their original power. Newer models often feature glass on both sides instead of plastic, which experts believe could extend their lifespan up to 40 years. Other components such as inverters, which convert direct current into alternating current, need replacement after roughly 15 years, while batteries typically last between 10 and 15 years. The steel frames of modules can last between 30 and 50 years, whereas aluminum ones have a lifespan of 25 to 30 years. The Swiss solar park Mont-Soleil has been reliably producing electricity since 1992, and newer modules generate twice as much power per unit area compared to the first generation. Which materials from solar panels can be recycled? Over 85 percent of a module’s weight can be recovered. Some materials offer particularly high value. Aluminum frames can be easily removed and melted down, yielding about four euros per module. Glass makes up 70 percent of a module's composition, weighing between 10 and 17 kilograms. It can be repurposed into insulation materials, valued at less than one euro per module. Silicon, the semiconductor used in most common modules, can be refined for new solar cells, worth about one euro per module. Silver, the most valuable material within a panel, contains approximately 19 grams in the thin silver conductor tracks of solar cells. Specialized processes are required to recover this precious metal, valued at around 25 euros per module. Copper used in wiring for connection boxes is worth about one euro per module. In some recycling plants, aluminum frames, glass, and connection boxes have already been separated. Now, the focus is on removing the silver conductors from the cells and separating the back-side foils. However, plastic components and foils are currently not being recycled. How difficult is solar recycling? Solar panels are built to withstand extreme weather conditions, including heavy rain, hail, intense heat, and frost. As a result, they are produced to be highly durable. The solar cells, plastic film, and glass are bonded together under high temperatures to form a solid sandwich. Separating these tightly bound materials presents a major challenge. Recycling facilities employ hot knives, powerful light flashes, ovens, and acids to break them apart. A combination of different methods allows up to 99 percent of valuable materials to be recovered in high quality. However, this process is costly, so not all materials are always recycled. Recovered materials can be used to manufacture new panels, computer chips, or window glass. Simpler recycling plants require less energy and chemicals but may not retrieve all materials in high quality. For example, slightly contaminated glass is used to make fiberglass insulation. So far, unused plastics remain unprocessed. They either partially decompose at high temperatures in furnaces or end up in incineration plants during mechanical separation. Where do old modules go? Recycling regulations for solar panels are not yet established everywhere. Countries like Germany, where many solar installations have been operating for years, are further along in developing recycling infrastructure. The European Union leads the way, with legislation mandating at least 80 percent recovery of existing installations.