We all know that you can siphon off liquid from a container by sucking it up a tube until the liquid is travelling of its own volition. I don't know what the scientific principle behind it is called, but anyway, we all know about it. Well, if a gigantic tube (or multiple tubes) were placed in the ocean and made to suck out the water by this process (initially you'd use powerful pumps to start the process, but then, the water would siphon out of its own accord), the energy of the water coming out of the tube and dropping from a height, could be used to power generators sited on platforms underneath it, to produce very cheap electricity. The best thing about this, is that you wouldn't need to use any energy to pump out the water, except for the start up phase and it would never stop! Am I wrong in this assumption? If I'm not; why hasn't it been attempted?