Bad luck for the guy having his house under the solar panels. He will have no sunlight even if there are no clouds on the sky ;)
Which means the time of 'transit' would be the time the image of the sun takes to move a single solar diameter across the sky, and only for those people who are in the line-of-sight, so it would be a different group of people almost every time this happens, at most twice every year.
No such 'guy' would exist.
for example planes flying at 35k feet don't cast visible shadows.