Mr. Krabs' Jellyfish Jelly Factory is a makeshift factory Mr. Krabs built in the episode "Jellyfish Hunter." It is powered by the energy produced when Mr. Krabs pedals a bicycle. The factory has not appeared since.
Since the entire factory was powered by only Krabs's bike, this factory would be powered when a spinning piece of metal generates the power on something else (magnet with copper) thus powering the machinery. However, when he wasn't using the bike, the voice-activated door of the tank that was keeping the jellyfish had power to operate.