On March 9th, two Swiss pilots on took off from Abu Dhabi in the UAE to attempt the first round the world journey in a solar plane without using any fuel. As of today, they have completed the first two legs of their journey and are in Ahmedabad, India. They have planned to take five months to complete the journey. During their pit stops, they are spreading the message about clean technology.
The Solar Impulse-2 has 17,000 solar cells on the wings and has lithium-ion batteries to sustain the motion during the night. The plane is powered by four under wing electric motors. The plane is 236 feet wide, which is just a bit wider than a 747, and weighs 5,070 pounds. In comparison the Model S weighs 4,630 pounds. The average speed is expected to be about 43 miles per hour.
The longer legs of the journey will be quite difficult as the cockpit is very small. Over the oceans they will have to endure sleeping in only 20 minute stretches.
You can follow their progress on their website.