Forget Installing Solar Panels, Make Roofs Out Of Solar Panels Instead

An idea which comes and goes. This one seems to come by every summer since, what...1956? I saw the idea in one of the old Popular Mechanics I have in my waiting room and that issue dates to 1965. They still don't make shingles out of photovoltaic cells. And why should they? Why would anybody think that expensive and delicate photovoltaic cells would make a good shingle?

The job of a photovoltaic cell is not to shed water or snow...its job is to make electricity. The job of a shingle is to keep snow, ice and water out of the house. Is the photovoltaic cell rated to handle snow loads? How about tile movement re-hot and cold? And if you get hit by hail (or junior's baseball), and the tile gets smashed, what do you use to keep the rain out of the attic? Got another tile of exactly the right size and wattage stashed away for such eventuality? How about flashing, and what do you stand on to do repairs? Who do you get to do the job, and how do you write the code to allow for glass shingles? Heck, we can't get contractors to follow existing codes, let alone something like this!

Why bother? Somebody think this will save a buck somewhere down the line? Why is it not commonly done now?