Thanks. I've seen those. Still too expensive to be practical, I'm afraid. However, the technology being discussed in this post might just do the trick. Once it's possible to get away from crystalline silicon, there's a good chance that such roofs will be cost effective.
A guy I know has a summer cabin on a lake. He's off the grid, but not by choice. He uses, like most cabin owners, a generator for most of his electrical needs, but does have a large array of traditional solar panels for some uses, including refrigeration, using peltier-effect.
He stores electricity in gel-cell batteries during the day, then uses it after dark, as needed.
Is it cost-effective? For him it is, since it allows him to use a smaller generator than he would otherwise and reduces the amount of diesel fuel he has to haul into the cabin. It doesn't go much past the break-even point, but it does break-even. Many nights, he uses only the lights, etc. that are solar powered and leaves the generator off.