Worried about the long term energy future of the world? Fret no longer my friend the laws of thermodynamics do not apply! (Well; they still do; but this could help us circumvent the energy limitations of our planet). The fact is the human population is growing at an exponential rate along with our energy consumption and despite what some people assert, we will eventually burn through our stock of carbon based fuels. Sure we know of many other forms of carbon energy such as oil sands, and new techniques such as fracking will allow us to extend the rein of our carbon based energy economy, but this paradigm will not last forever.
Think this idea seems far fetched? Remember private companies such as SpaceX are working hard every day to lower the cost per pound of putting assets into space. The long run future is so bright I gotta wear shades! its just what happens in the interim that makes me nervous.