Smithsonian — January 8, 2014 | Tuan C. Nguyen

This is a summary. Read original article in full here.

Nearly six years ago, futurist Ray Kurzweil predicted that, within 20 years, solar power technology would advance to the point where it would be able to supply all of the world’s energy needs.

His optimistic forecast wasn’t too far-fetched considering that the amount of energy Earth receives in just one hour would be enough to power humans’ lives for an entire year. […]