With the capability of 5 days of continuous flight, the first solar-powered aircraft could literally stay in the air around the clock. With the weight of just the average automobile (around 5,000lbs ) this will be the most efficient plane in the sky. So what happens during night time? Well, the power conservation is actually strict enough to the point where the output of the aircraft will be a little below 16hp over a 24hr period. The motors that this output will be put into are actually 97% efficient so there will be little energy lost with the plane. Check out the full story HERE.