According to various embodiments of the invention, systems and methods for attaching a solar panel to a roof are provided. A solar panel generally comprises a solar cell and a frame enclosing the solar cell. The frame may be configured to interface with a conventional roof shingle in an overlapping fashion. In some embodiments, the frame includes an integrated rain-rail configured to provide a conduit for rainwater and mate with a rain-rail on another solar panel providing a mechanical interconnection between the panels. The solar cell may also include a tack-down strip configured to connect the solar panel to a roof. This tack-down strip may be configured to overlap a shingle on a roof.