Solar panels are often installed on roofs for optimal sunlight exposure and stability. Roof-mounted systems are divided into two types: pitched roof systems and flat roof systems. Pitched roof systems, used mostly in residential setups, include railed and railless options, both requiring roof penetration for attachment. Railed systems use rails for support, while railless systems attach panels directly for faster installation. Flat roof systems, common in commercial settings, often use ballast to secure panels, which are typically tilted between 5° and 15° for optimal sunlight. Some setups use an east-west dual-tilt configuration to maximize energy production. Various designs, including pre-cast concrete systems, provide installation flexibility.