What are the different types of solar panels?

Main solar panel types: Monocrystalline silicon (single crystal, highest efficiency 18-22%, black appearance, premium cost), Polycrystalline silicon (multiple crystals, 15-17% efficiency, blue appearance, lower cost), Thin-film (deposited layers - CdTe, CIGS, a-Si; 10-13% efficiency, flexible, lower cost per watt but needs more area), and Bifacial (captures light from both sides, higher energy yield). Selection depends on space constraints, budget, and application. Monocrystalline dominates residential rooftops; thin-film suits large ground-mount installations.