It's Alive! The world's first algae-powered building (video)
There is a building in Hamburg, Germany, which is entirely powered by algae. Inside the glass panels is a green liquid in which you can see little bubbles rising to the surface.
This is the result of having a bio-reactor built into the facade, which heats the 15 flats in the building. The motor is micro algae, and the principle is photosynthesis.