Solar panels vs shade cloth

I, too, lack data, but just from a basic understanding of physics, it would seem reasonable to me that black solar panels with a white back side raised at least an inch or two above any roof would result in significant temperature drop on the roof. The white back side of such panels would not radiate much of the heat created by the black side facing the sun. So I'm not at all surprised by @RambleOnNW's measurements.

Shadecloth would not be expected to result in anything better than solar panels, but I bow to anyone having actually measured the difference.