Solar energy is an obvious starting point for renewable energy because it is free and abundant.  If it can be efficiently collected it can greatly supplement if not replace our energy needs.  This video shows an alternative process of collecting this free solar energy and converting it to useful mechanical energy.   It is mentioned that the energy output is three to four times greater than with a panels the same size.  it appears this could be an efficient solution to many energy needs if produced on a larger scale. 

Things to Think About:  Could this process easily be replicated on a larger scale?  Are there more efficient processes of solar energy conversion?  How much energy could ultimately be produced?