WRT the solar window solution, I think it is ultimately going to be via coatings. Both acrylic and polycarbonate glazing panels have failed (over decades) to overtake glass in the window market. They are lighter weight and provide greater impact resistance so they have niche applications, but they are almost double the cost and are soft, so they scratch like crazy, even with protective coatings. (Think bus-stop shelters.) Also, the major global producers have spent millions trying to penetrate the auto glass market with very limited success; the scratching problem has never been overcome. And lastly, polycarbonate absorbs some UV and yellows.
