Lots of panels are installed DIY. And the transformers are the big problem. Also, when they are on fire, the fire brigade can't extinguish, because the fire nests between the panel and the roof... Matter of bad design. We should integrate...

Multifunctional is the best solution always. Less material. Best designs.

And of course, no transforming. Why would we? All houses have electronic appliances. We can easily do 12-24V DC without a transformer... Replace something with nothing. No batteries. Direct use. And only the extra on the grid. That solves the problem of overfilled grids...