Mounting clamps may be utilized to quickly and easily secure solar panel modules relative to mounting rails, which may in turn be secured relative to a mounting surface (e.g., a roof). The mounting clamps may be configured to quickly secure the solar pane modules relative to the mounting rails by tightening a tightening element to pull a clamp element toward the surface of a mounting rail, thereby clamping a portion (e.g., a frame) of a solar panel module between the clamping element and an outer surface of the mounting rail.