Mini Project Help!

Hello all. I'm presently doing my third year in EEE and since I've managed to waste away the last 2 years without doing anything even remotely meaningful, I've decided that it's time that I got my act together. That is why I proposed to do a mini project with the help of a reputed Prof in my department.
The Prof wants me to do a project where we will able to power circuits using renewable energy sources and suggested I google that topic and see what I come up with.
I guess I was searching for it in the wrong places because I couldn't find anything meaningful for said project.
Hence, I'd really appreciate it if any/few of you scholarly dudes and dudettes out there impart some of your wisdom to me by giving me some input with regard to my project.

Cheers!

PS: First post. So go easy on me.
PPS: I know what the topic means. But, I unfortunately don't have a clue as to how I can translate the project topic into...an actual project.