An experimental solar-powered aircraft Solar
Impulse 2 has large fixed wing covered from tip to tip with 17,000 photovoltaic
cells providing 340kW of electric power. The aircraft is powered by
taking off in the daylight and rising to an altitude of 9,000m as the sun
charges its batteries.
At night, the engine is switched off and the plane
glides down to 1000m, and then the plane needs to find cloudless sky to charge
its battery in the morning so as to fly continuously. Professor of Aeronautical
Engineering, Professor Chris Atkin, says that "the limited potential for
solar-powered aircraft is instructive. Solar energy density is something like
0.25 kW per square metre, assuming that these solar cells are one hundred
percent energy efficient. An Airbus A330 aircraft burns 60 kW per square metre
of wing area, i.e. 240 times more than would be available from perfectly
efficient solar energy capture”. Read more at http://www.idtechex.com/
