Solar-powered desk fans?

Unfortunately, it looks it's extremely hard to find non-attic fans, in particular smaller models that might fit in a window.

Since I've had such good luck with posting other items, I'm hoping that someone will come upon this and have some suggestions for where one can either purchase a pre-built, solar-powered, desk fan, or a site that walks through the creation process.

Even if there's no storage, it would still be nice on those warm days to have a fan that isn't pulling an electrical current ...