A solar power system can include an array of solar modules. The system can include a rail and a solar module positioned at an outer end of the array. The solar module can have a frame around a periphery of the solar module. The frame can include a flange along an edge of the solar module that is disposed at the outer end of the array. The flange can project inwardly from the frame underneath the solar module. A clamp assembly can be disposed underneath the solar module and can mechanically secure the solar module to the rail. The clamp assembly can include a clamp body and a base. The clamp body and the base can cooperate to clamp the flange between the clamp body and the rail.