Greetings R/trees! a man of the mind wants your opinions!

Hello everyone! w), I apologise if i am bringing up a topic that is not a ten guy post or a meme, i just want to talk to smart free minded people about this topic and /r/science and /r/technology both do not allow text posts, so i figured i would give my home a try. ANYHOW, recently I have become interested in the idea of free energy. Now before I even begin, we all know that energy cannot be created or destroyed, the same way we don't actually "use-up" electricity. So that being said, lets not talk about it for the sake of the argument I wish to make. I want to know what you all think the most efficient design for a "free energy" device would be. just to be clear my goal is not the front page or upvotes or anything. I just want to have a mind throbbing discussion on how to free ourselves from petrol, with anyone and everyone who wishes to participate.