Flexible solar panels differ quite from rigid, rectangular, glass-encased standard solar panels typically found on rooftops. Rather, flexible solar panels come in all shapes and sizes and are expected to be used in a greater number of situations than standard panels Whereas portable solar panels contain solar cells mounted in a lightweight, often plastic frame and thin-film panels are made of materials like copper, selenium, and gallium, flexible and standard solar panels use solar wafers to convert sunlight to electricity. Most often, flexible panels use wafers made from silicon, though they are far thinner than those in standard panels-as thin as merely a few micrometers in width. Whereas standard panels are sandwiched between layers of glass, flexible panels are placed between layers of protective plastic.