In 1522 a sailing vessel, named the Victoria, arrived in Spain and thereby completed the first circumnavigation of Earth using only sustainable power (wind). This voyage is generally called Magellan’s voyage, but the person who completed the voyage in command was Juan Sebastian Elcano.
Since that time, humans have circumnavigated Earth in any number of novel fashions including rockets, aircraft, and submarines, but with the exception of a balloon circumnavigation (Picard and Jones, 19 days, 1999), which is more akin to drifting with the wind rather than navigating, all those novel methods used fossil or external fuels in some fashion.
By water we have copied the Magellan feat any number of times using solar cells or much faster sailboats, and greatly improved on the circumnavigation time. The record for a sailing circumnavigation is 45 days and the record for a solar waterborne circumnavigation is 584 days. Not bad, noting that the original voyage took 4 years but these feats are really improvements on a method rather than a novel approach.
Only this year, almost 500 years later, are humans attempting to take a new approach.
This morning, March 9, 2015, Solar Impulse 2 took off on its first leg of a circumnavigation using only PV solar power. But instead of traveling on water, this voyage will be carried out by air. This voyage will have many stops and is expected to take five months, but if completed, we will be witness to a truly new chapter in human history. In the last century we transitioned from a waterborne to an airborne society, in this century we are transitioning from a fossil fueled society to a sustainable energy society and this attempt will be a really big step forward.
Moreover, it is a truly impressive technological feat, deeply international and privately funded.
Safe travels Solar Impulse 2.
For the best coverage I could find go to: www.bbc.co.uk