You will almost never get the rated watts out of a solar
panel (or wind
generator) if you don't have it operating in optimum conditions.
That usually means having the directly facing the sun in the sky.
This means you need the panel to be mounted on a tracking mount (which can be automatic or manual).
A flexible panel is pretty much designed to be a compromise.
They mount in a way that is unobtrusive, but they're rarely going to be operating at rated capacity.
It's just the nature of the design.
I've been mulling over ways to mount a 50 watt rigid panel that I have in my basement.
I've been looking at something like this...
I also need to come up with a mount for a 60 watt wind generator