Solar Impulse - The Solar Plane That Wants To Circle The Globe

We're closely following the Solar Impulse story -- a terrific solar adventure.  An excerpt from The Economist is below.  What's interesting about the story is that it underscores that solar battery technology has come a long way, but just isn't there yet --and that doesn't stop solar viability!  In fact, the plane shows how solar works best when it aligns with peak demand time --like it does with commercial solar right here on the ground.  

Here's the excerpt:

On March 9th André Borschberg, a Swiss fighter pilot and engineer, took off from Abu Dhabi at the controls of this flimsy solar-powered aircraft, Solar Impulse 2, on the first leg of a journey around the world. Despite its 72-metre wingspan, the plane has room for but a single pilot—a job Mr Borschberg will share with Bertrand Piccard, a psychiatrist and balloonist who helped start the Solar Impulse project a dozen years ago. Flying east, the two will take turns to complete the 12 legs of the trip over (they hope) the next five months. The most difficult stretches, such as an 8,170km flight across the Pacific from Nanjing to Hawaii, mean spending five days continuously aloft. The plan is to climb during the day to 8,500 metres while the 17,248 solar cells on the plane’s wings and fuselage both drive the four propellers and top up the batteries. At night the pilot will descend gradually to 1,500 metres, eking out the electricity until sunrise as he does so.

Here's the link.