theproblemofincreasinghumanenergy

One of the things I like about reading "The Problem of Increasing Human Energy" was the concept of the evacuated chamber in a lake.  Water is allowed to pour into this chamber, where it undergoes electrolysis using the energy generated by the water passing through the turbine.  I think it would be a noble thought experiment to take this thought out and perform the math to see how tall this tower would need to be before 'free energy' is generated.  That is, more energy output than input. In the book, The Problem of Increasing Human Energy , This is probably not the tower you have come to picture when thinking about Tesla, but it is certainly one of the many fascinating ideas in his book, "The ..." . Nikoa Tesla talks about a hypothetical situation where a void is created in a lake, and water is allowed to flow in. As this water flows in, it performs mechanical work, and the mechanical work is turned into electricity. This electricit