Hopefully we will come up with better technologies to harness energy variants that we currently have, yet cant efficiently make available. Fossil Fuels are seemingly the only practical energy source as its currently the only one we can sufficiently supply ourselves with, and most of our transportation technology is focused around it singularly anyways. I'm not a huge fossil fuels fan.. I wish we could be done away with coal and oil. Honestly, if was a means to efficiently siphon energy, I would assume some practical way of harnessing the suns energy would be... well, the most practical. It does provide the most energy of any object in our relative vicinity.. The answer will probably lie in mankind's ability to create new elements that exhibit the qualities for better energy storage.. Honestly, I have no real grasp on energy outside of how an 2 and 4 stroke engine work, how electricity works, and the general overview of how our basic batteries work.. lithium ion technology, solar power, crystal batteries, and the like are all subjects I could use a good brushing up on.. I am digging this thread though, and nice vid find SOTB.