A clamp described herein can secure a solar cell array to a seam of a standing seam metal roof. The clamp has a cam that is rotated by the tightening of a bolt to cause the cam to engage the seam. The clamp also has a receiver for receiving the seam and the rotated cam. By installing the clamp on the seam, the solar cell array can be secured to the standing seam metal roof without drilling into the roof. Because no screws are required to be drilled into the rooftop, the damage to the rooftop is substantially reduced. Also, by reversing the process described above, the clamp can be uninstalled in a similar fashion.