Many of us take "the grid" for granted — but without it, society would cease to function. Our homes, offices and communities all depend on the energy infrastructure to supply a reliable, steady stream of power.
Yet every grid has its limitations. "The grid can only transport a certain amount of electricity, the reason being the actual physical construction of the cables," Clemens Triebel, Chief Visionary Officer of Germany's Younicos, told CNBC's Sustainable Energy. "When too much energy wants to flow, they will overheat – just as in every home there is a fuse and that will simply shut off."
So then the problem becomes how to store this excess energy. When it comes to renewables like solar and wind, the challenges facing energy storage are manifold, because while these sources are good for the planet, they do not promise a constant stream of power.
Read MoreMud: The world's next powersource?