Basically if something is too small or not sturdy enough to accommodate the size or weight of regular solar panels ... bit more unique to OPV panels is the variety of colors they can be produced ...

“This work highlights the potential of this new generation of organic dyes for future applications in semi-transparent solar cells.” The mini-panel is described in the paper Benzothiadiazole ...

A group of scientists led by the US Department of Energy's National Renewable Energy Laboratory (NREL) has designed a monocrystalline mini solar panel that can convert laser light into electricity.