And a recent breakthrough by scientists at the Lawrence Berkeley National Laboratory could make harnessing this energy for human consumption a reality.

Researchers have developed an "artificial forest" that can convert solar energy into chemical fuels.

In a process that mimics photosynthesis, this artificial forest soaks up light and uses it to generate oxygen and hydrogen, two gases that can be used to power fuel cells.

"To facilitate solar water-splitting in our system, we synthesized tree-like nanowire heterostructures, consisting of silicon trunks and titanium oxide branches," said Peidong Yang, a chemist at Berkeley Lab's Materials Science Division and lead scientist for the study. "Visually, arrays of these nanostructures very much resemble an artificial forest."