A system for mounting solar modules comprising a plurality of racks and clamps. Each rack has an inclined upper mounting surface to support one of the solar modules and an inclined lower mounting surface to support one of the other solar modules. Each upper mounting surface and lower mounting surface define a slot. One of the clamps slidably receivable by a slot of one of the upper mounting surfaces and configured to secure the one solar modules to the upper mounting surfaces and an other of the clamps slidably receivable by a slot of one of the lower mounting surfaces and configured to secure said one of the other solar modules to one of the lower mounting surfaces. Each rack has a tray having a first tower supporting the upper mounting surface and a second tower supporting the lower mounting surface.