More than 85% percent of a solar photovoltaic (PV) module is made of materials we already know how to recycle, like aluminum and glass. However, solar panel recycling—and recycling overall—is not currently cost-effective or widely adopted. Making solar module recycling ubiquitous will require a combination of technology and policy innovation. To make a larger impact on reducing waste and other environmental impacts from solar technologies, actions need to be taken before a module is even made.
The U.S. Department of Energy Solar Energy Technologies Office (SETO) is thinking outside the box, innovating the way we design and manufacture panels so they can produce less waste and use more optimal materials. SETO funds research into replacing expensive, rare, or environmentally harmful materials used in solar module production. For example, some SETO projects are working to replace the expensive silver contacts that carry electricity out of a solar cell with copper or aluminum.
Several of our projects are also designing modules with new materials that make them easier to deconstruct. One approach uses sealants that can be dissolved without damaging other panel materials. Another contains layers that allow sections of the panel to be cleanly “unzipped” from others. This ability to easily disassemble solar panels makes reuse, repair, and recsycling processes simpler and more efficient. Projects are also investigating ways to reuse waste materials created in the manufacturing process, such as the silicon dust generated by slicing large pieces of silicon into wafers for use in solar cells.
Keeping solar panels in the field longer by making them more durable and easier to repair will also slow and reduce the flow of solar panels into the waste stream. Panels manufactured in the last decade are likely to last 25-35 years, but SETO is working toward 50-year lifespans. An increase in average module lifetime of 2-3 years could decrease waste by 2-3 million metric tons by 2050.