Its a great green energy initiative. Amazing thing about this aircraft is that its not about how long it can fly for, BUT how long the pilot can fly it for. This thing can remain in the blue skies for days, as long as the pilot is in a proper state of mind. Another amazing fact about this airplane is that it was never made for pilots to control. The **** pit is only there so a pilot (engineer/scientist) can learn about its in and outs while its in the air. The main focus is on the battery and how solar power is made. Once, they achieve this task, the cockpit will be removed and it will become an unmanned ariel vehicle. It is extremely uneconomical to place enough computers to study this aircraft instead of placing a pilot who only weights around 150 lbs and can function much better than a computer or a robot.
Few cons
Airplane does use fuel to take off, once it reaches its desired ceiling, it uses the solar battery
Scientists haven't developed a battery powerful enough to keep this thing in the air in winter since days are shorter and the battery can't use sunlight for long.
This airplane is very congested