Photovoltaic mounting systems and coupling assemblies for mounting photovoltaic modules are provided. The mounting systems may include short extruded base members that are mounted onto the supporting surface at approximate locations on the supporting surface, and coupling assemblies that may slide along the length of the base members during installation and be locked at particular positions on the length of the base members. The coupling assemblies may be coupled to connectors that in turn couple to two photovoltaic modules. In operation, the installer may first determine approximate locations on which to mount the base members and mount all required base members, and then, place the coupling assemblies at desired locations, lock the coupling assemblies at the desired locations, position the photovoltaic modules in the connectors of the coupling assemblies, and move to the next set of coupling assemblies.