Solar Panel Grounding Options

Is anyone familiar with the Unirac grounding accessories for their standard rails? Do both of these grounding accessories need to be used?

GROUNDING CLIPS


GROUNDING LUGS


I can understand how the grounding lugs are used on each panel to allow the continuous ground wire to "lay in" each lug on each panel. I'm not sure I understand how the ground clips are supposed to work. If I saw them in person (installed), then they would probably make more sense to me. I'm just trying to understand what would be needed to ground the panels. I'm guessing it's an "either/or" on the clips and lugs, but I can't really see how the grounding clips work.

Edward