On the one hand, putting a tiny screen on USB flash drives so you can quickly and easily see just how much space is available without having to plug them into a computer is a good idea. And if they need power, I suppose getting it from the sun isn't such a terrible idea.
On the other hand, I'm pretty sure not a single one of the USB flash drives that I own have ever seen sunlight. I mean, who uses these things outside? They sit in drawers and in pockets and at the bottoms of bags, not out in fields where they can soak up the rays. And unless you do all your computing outside, this thing is gonna be a real pain to juice up. But hey, you're getting there, designers.