A support assembly for mounting photovoltaic modules on a support surface and a mounting system including the same are disclosed herein. The support assembly may comprise a the body portion including a base portion and at least one upright support member coupled to the base portion, the at least one upright support member comprising an integrally formed ballast tray slot in one side thereof for receiving an upturned edge of a ballast tray; and at least one clamp subassembly coupled to the at least one upright support member of the body portion, the at least one clamp subassembly configured to be coupled to one or more photovoltaic modules. In addition to a plurality of support assemblies, the mounting system may further comprise at least one ballast tray support bracket, the ballast tray support bracket supporting a portion of a ballast tray on the support surface.