Well, the innovation is really about storing electricity. We've been generating and transmitting electricity for over a century now.

Once we can store electricity (in batteries, for example), then intermittent power sources, like solar panels (and also wind turbines) become much more valuable.

Energy storage is a very inconsequential market right now, but if smart-grid-connected Teslas really take off, then they become important not only to the automotive industry, but also the electricity and energy industries.

Once solar cells hit a tipping point, storage becomes one of the best businesses to be in.