A solar-powered plane successfully completed its latest test flight in Abu Dhabi Monday, clearing the way for its planned round-the-world trip.
Solar Impulse Chairman Bertrand Piccard piloted Monday's test flight and was expected to man the fifth and final trial flight later that day. The plane will be the first to circle the globe run entirely on solar power if all goes to plan.
Weather permitting, the Solar Impulse 2 (Si2) will depart from Abu Dhabi's Al-Bateen airport on Saturday and return in July or August. The plane will travel between Oman, India, China, Myanmar, Hawaii and the continental US. Once across the Atlantic, Si2 will stop over in Southern Europe or North Africa before returning to the UAE.
Lithium batteries will help store energy from the plane's 17,000 solar cells, allowing the aircraft to fly at night.
Speaking to CNBC in Abu Dhabi, Piccard explained that the Si2 has been built with that ability to store 30 percent more energy than the prototype.
"This is the most important thing: it's the energy density of the batteries and of course the efficiency of the entire plane. This airplane is more powerful and more efficient than the previous one, especially the motors….and it is 97 percent efficient. You have 3 percent of losses, that's nothing compared to thermal engines," he said.
Si2's predecessor already set seven world records for solar flight including height gain, free distance and for completing a 26-hour day and night trip.
"You know, the world can be so much more energy efficient," Piccard said, "and that's what I'm fighting for."