Solar Plane Successfully Completes Maiden International Flight

so cool. i wonder how much energy was used for take off compared to the total flight?

 

Actually, the real conceptual difference is that solar panels don't get lighter as the flight progresses.

A real practical issue is that the energy density just isn't high enough yet. Cloud cover is a minor inconvenience for long flights, just fly above it, especially in a plane which doesn't need oxygen for combustion.

 

Video: Solar Airplane’s Maiden European Flight | Autopia | Wired.com

IMHO if you don't put seriously bigger batteries in the plane, every flight will be a long flight. Climbing above the clouds takes a great deal of energy, and in this plane time.

 

this is awesome.. I feel like I am going to see something cool like space flight in my lifetime..

 

And bigger batteries aren't heavy? At present, batteries are just about a break even proposition: the batteries are just about powerful enough to haul themselves into the air, but not for any appreciable length of time. This means that effectively all of the power comes from the solar panels for anything longer than a trip around the patch.

Tom

 

If you look at the project page, the plane is designed to run on battery power all night, and has completed a 24 hour flight. It says the primary limitation on performance is battery capacity, which is what I wrote. Battery weight is a problem and currently is about 1/4 of total weight. The solar panels need to be big enough for cruise and storage power, the batteries big enough to take off and accelerate and maintain speed at night.

 

I remember watching interview with plane designers few years back, and they talked about night flight. They actually use surplus of solar panel output to climb during the day, and during night they descend and loose something like 7-12,000' . Not a bad strategy, much better then carrying bigger batteries.

 

I was just going to make this point, but you beat me to it. I assume they used a similar strategy with this new aircraft, as it uses the weight of the aircraft to store energy.

Tom