Solar-generated electricity is booming worldwide and is forecast to continue its rapid growth. The typical life span of a photovoltaic (PV) panel is 25 years. Already, some of the earliest installed panels are at this end-of-life age. The number of panels taken out of service will only grow exponentially going forward. The coming solar e-waste glut is expected to be in the millions of tons within the next decade. The main solution being explored is recycling.
A solar panel can be thought of as an electronic sandwich: The filling is a thin layer of crystalline silicon cells, insulated and protected by sheets of polymer and glass, all held together in an aluminum frame. The most valuable recoverable elements are copper, silver, silicon, and aluminum. A single panel will yield about $3 worth of these materials, while the cost of recycling is between $12 and $25, not counting transportation. The cost to dump a PV panel in a solid-waste landfill, where allowed, is typically less than a dollar. These numbers do not add up to a winning business opportunity. When panels enter landfills, valuable resources get buried. Moreover, because PV panels contain toxic materials, they can leach out in landfills and create new environmental hazards.
The European Union is in the avant-garde of PV recycling. Manufacturers are required by law to be financially responsible for the retirement of the panels they produce. In Japan, India, and Australia, recycling requirements are being developed. In the U.S., coping with solar waste is basically voluntary, unregulated, and haphazard, yielding a recycled rate of only about 10 percent. Because of the European mandate, pilot projects on the continent are exploring new panel designs to allow easier recycling of component elements as well as new equipment that can recapture a higher percentage of material while separating it better.