Solar cells on an A-380 -- or better a 787 -- could take some of the generator load off the engines and save fuel. At least if they weren't too heavy . . .

But except for maybe communications or surveillance platforms, solar aviation seems like something to think about after we've shut down all the fossil fueled power plants and are all driving electric cars. The Impulse is a great demonstration of solar in general, but I'm not convinced about solar aviation.

I was about to contribute something along the lines of contributory power systems, as opposed to primary power systems. Chu Chu makes an interesting point.
Consider the situation with cruise ships. Several designs have now been created that have big automated sails as well as fossil fuel power sources. These significantly reduce the fuel requirements for the journey, and aren't just for pose value. Cost/value remains marginal, or they would all use them.

Consider the aviation world again. Personally, I rather like the idea that the A320 or 777 with 2 engine failure and a loss of electrical power might be able to rely on alternate PV power for the instruments/radios/computers/actuators enabling a controlled glide descent to an airfield. I don't imagine that you'd need too many m2 of pv to power the electronics.

Quite an expense for something that would be very rarely needed and then would only work half the time

300hrWannaB...

Ummm, well regardless of the expense perhaps one way around the possible lack of daylight would be to use wind power instead of solar.....:E

Edit to add: Sorry, on second thoughts even for me that comment's a bit cruel. 300hr, Most commercial twins have "Ram Air Turbines" or "RATs" to help cater with, amongst other things, a double engine out.

https://en.wikipedia.org/wiki/Ram_air_turbine

The place where this tech makes a lot more sense is on this beast....

http://www.pprune.org/military-aviat...hicles-uk.html

Plenty of area, minimal thrust required most of the time.

Solar panels are not weight free, and neither is the supporting wiring/inverters/etc.

Watch some of the videos about solar impulse. The are extraordinarily light. More than worth the trade-off on something like a blimp, and getting lighter and more efficient by the day.

yes, 1,600Kg's light.... and carries one person.

That's 1600Kg for the aircraft Scuffers, not the solar panels.



I don't disagree with you re the viability of solar powered passenger flights in heavier than air vehicles, but the applicability of the tech to blimps is obvious.

Zephyr has better than 1KW per Kg. Not bad, and getting better all the time.

The big problem here is that it's a tenuous bit of tech without a real application.

What's the 'must-have' application for blimps?

short answer is - NONE. if there was, they would be out there now being used.

People will then go on about using them for internet connectivity etc, but being blunt, this is a non starter too, (if anything, Elon's SpaceX will be the big step forward for global networking).

Look, I am not anti solar, just that this is NOT the right application.

By "this" do you mean passenger travel or Blimps?
Or ultra long endurance UAVs?

The last is very much a starter and in production now.

There was absolutely no "must-have" application for anything like Predator/Reaper.......

....and then some clever chaps built one despite zero interest from anybody.

Solar panels only work with daylight, so need to store energy for rest of time , means batteries, additional weight and problems ( not only 787 but also Solar impluse /Hawai )
However great potential for GA / daylight ops. Many Gilders today already use this to keep battery power at max.

Last bit on RAT and Airbii : visit at Air Transat A330 /Azores and Air Asia A320 /Java final reports to see the limits of RAT power.

My personal imagination tells me that the potention real-world application of this is that solar powered UAVs with sufficient battery capacity to get them through the night could be launched for long missions of weeks, months or years.

With further advances thes vehicles could possibly maintain altitudes above weather and commercial traffic.

The commercial and/or military applications are huge. These vehicles could essentially perform roles currently only available to satellites at a fraction of the cost. A bit scary too... Big brother gets closer and closer.

Google would probably deploy a few thousand of them to provide low cost broadband to the world (in lieu of it's fanciful blimp idea). By my calculations they would need around 4000 of them to cover the entire globe at 200NM spacing. Obviously the poles would be a problem in winter.

The point of an around the world "stunt" in a manned vehicle isn't to demonstrate that we could all someday be flying in solar powered A380's. The point is to generate media attention, the attention of scientific bodies and governments, the attention of venture capitalists looking for the next big thing, and to get you and I talking.

It's not beyond my imagination that we could develop the technology to the point where we could launch a low cost UAV to FL500 and leave it on a set course (or a holding pattern) for a year or so carrying a useful communications payload.

Now in Tulsa Solar Impulse - 11th Leg from Phoenix to Tulsa

the problem with that is LEO satellites are getting much cheaper every month as are the launch costs, to the point SpaceX are already looking to launch their own LEO constellation for net connectivity (the way they are heading is looking like they could put up enough in 2 launches to cover the planet).

in reality, the number of planes/blimps/whatever to do this job would simply be far to expensive and have too high a running costs for anything practical.

Lucky 13 ... enroute to Pennsylvania

Solar Impulse - 13th Leg from Dayton to Lehigh Valley

En route to JFK:

Historic flight over the Statue of Liberty
This flight will bring Solar Impulse over the Statue of Liberty to New York City, with a final landing at JFK.

"Most people laughed at the Wright brothers 'wasting their time and money'"
Not the same thing. Sunlight converted to electricity doesn't have enough energy density to make this "fuel" viable......... EVER.

Your analogy to the Wright brothers is like saying, "Improved satellite cameras and the proliferation of camera equipped drones along with millions of cell phone cameras means we're on the verge of proving that unicorns and Yeti exist.

Of course, I don't remember hearing much about commercial applications for the Gossamer Condor or the Rutan Voyager. Sometimes a feat of aviation is just that.