Solar Panals use light energy (photons) from the sun to generate electricity through the photovoltaic effect. The Solar Panals structural (load carrying) member of a module can either be the top layer or the back layer. The majority of modules use wafer-based crystalline silicon cells or thin-film cells based on cadmium telluride or silicon. The conducting wires that take the current off the panels may contain silver, copper or other conductive (but generally not magnetic) transition metals. Read More on Solar Panals