There are two main types of solar panels: crystalline silicon solar panels and thin-film solar panels. Crystalline silicon solar panels are the most common type of solar panel. They are made from silicon crystals, which are arranged in a grid pattern. Thin-film solar panels are made from a variety of materials, including silicon, cadmium telluride, and copper indium gallium selenide. They are thinner and lighter than crystalline silicon solar panels, but they are also less efficient.