A photovoltaic mounting structure includes a frame for holding a photovoltaic array including a plurality of widthwise channels so as to permit photovoltaic modules to be easily slid between pairs of the channels, the photovoltaic modules resting upon flanges of the channels. In various embodiments, domed protrusions are disposed on lateral sides of the channel to prevent kinking of the modules and reduce friction, retention teeth are formed on upper surfaces of the flanges to position the modules; locator teeth are formed on lower surfaces of the flanges to guide the channels to predetermined spacing; and pre-installed mounting clips are attached to a top surface of the channel. The mounting clips each include an anti-rotation tab oriented downwardly and partially disposed in a corresponding hole in a top surface of the channel so as to prevent rotation of the mounting clip when a bolt of the mounting clip is rotated.