Wire or cable holder assemblies employed in a solar power system are disclosed. In some embodiments, an assembly could include a cap and a base configured with channels. When the cap and the base are clamped to an object (e.g., a solar module frame), enclosures defined by the channels and a surface of the solar frame module are formed to hold cables. In some embodiments, an assembly could include a plunger with at least one leg and a base that includes a receptacle for receiving the plunger and a hook for holding electrical cables. A leg include a rack having teeth adapted to fall into notches or spaces formed by complementary teeth of a pawl found in the receptacle that forms a ratchet which permits insertion of the plunger into the receptacle but not an extraction. If extraction is desired, an external force may be applied to release the pawl.