Which type of roof solar panel is better

When choosing rooftop solar panels, you should look for materials known for their strength and longevity such as polycrystalline silicon, which is both light-weight and resistant to corrosion; monocrystalline silicon, which is more efficient but more expensive than polycrystalline models; thin film cells made from copper indium gallium selenide (CIGS) or cadmium telluride (CdTe) that are flexible enough to bend around corners; and amorphous silicon modules that are lightweight but have lower output efficiency than other types of solar cells. [pdf]