Yes, there was a power source. We had to push it to get it started. I'm not sure how long it would run, though. It was an ugly paper device sitting on my kitchen table. I threw it away. I needed the table for dinner.
It was a kids science project, not a devise designed to save the world, you know.
It was easy to build. Just make sure you use materials like toilet paper or tissues for the blades. If it's too heavy it won't work.