If you are living in an area where it is cold in the winter, having a cooling coating on your roof is probably not the best use.

Every roof is not proper to get solar PV, it can be shaded for example. And you can find many application besides roofs : cooling vehicules like buses or trains or bus and train stops. Current applications are used also for technical appliance : pipes, outside electrical closet…

PDRC also comes as fabric, it would be possible to use it to cool down a small street between to building, or make a cooling hat, or a folding awning for houses, a car cover…