Solar plane flies over San Francisco Bay

[wtmusic]

"A solar powered plane flies over San Francisco in preparation for a planned cross-country flight in May. The lightweight plane flies at around 3,000ft as it passes over the Golden Gate Bridge. Considered the world's most advanced sun-powered plane, Solar Impulse runs entirely on energy from the sun."

http://www.guardian.co.uk/world/video/2013/apr/24/solar-plane-san-francisco-video

[Eleanors38]

1. That's god's own rudder on the tail...

I saw an early version with twice the number of motors. Does anyone know the energy storage technology when flying without the sun? "Lion" batteries?

[wtmusic]

2. Lithium polymer (flavor of lithium-ion)

"The aircraft had its first high flight on 7 April 2010, when it flew to an altitude of 1,200 meters (3,937 feet) in a 1.5-hour flight on battery power alone."

http://en.wikipedia.org/wiki/Electric_aircraft#Solar_Impulse

[Eleanors38]

3. Thanks. I bet there is a weight dividend. Anything which has "poly" in its description

seems to be an effort to lighten up. There was a thread yesterday about a University of Illinois project which is supposed to come up with a super battery with great power & storage capacity. It employs "plates" which are dented like an egg carton with the ovate holes cut-off. Or the reinforcing of thin plate metal with many holes punched through, like on very old pick-up running boards. The resulting pucker effect yields greater surface area.