Ideas

I think it was Rutan who built a solar powered aircraft. Basically, until the efficiency of photovoltaics gets a lot better (and it is every day), you can barely generate enough energy to push the plane. That doesn't mean you wouldn't get useful energy if you put solar panels on conventional aircraft; I'm just trying to scale the amount you'd get.

In order to fly correctly, aircraft are pretty carefully designed, so the solar panels would have to be embedded beneath a transparent skin that maintained the proper aerodynamic structure of the aircraft. That would make for a pretty expensive retrofit. I don't think the cost associated with modifying the aircraft would be worth the extra solar power you'd get by being at altitude compared to just putting the solar panels on the roof of the airport, etc.

It would be interesting to do a good economic analysis to see if this would pay back.

Micco,

I agree on all counts. The idea is not to make a solar-powered plane, but utilize the surfaces of planes and their direct exposure to sun to generate the electricity for sale to local companies. Therefore, the idea is to scale the electricity generation over a full fleet of planes.

And yes, the panels would have to be embedded with older planes likely being retrofitted and new designs incorporating the solar cells.

It can be done, NASA does it, here's an example of a solar powered plane from NASA called Helios, it's top surface is covered with solar cells. (see picture)

http://en.wikipedia....iki/Helios_Prototype

It's also being done on cars by the way:

http://upload.wikime...una3atZandvoort1.JPG

So the potential is definitely there.

...following on from this idea does anybody no whether it is scientifically feasable and cast effective to:

1. A farm of large concave lense's (the size of those giant radio telescopes SETI use) focusing the suns energy and storing the energy in some kind of material then directing the energy to a distribution grid ?

I'm not a scientist - so alot of assumptions here.

fpinto: I understand you weren't trying to power the plane. I was just using the solar-powered planes to scale how much power you can get. The solar-powered planes have to be extremely ultralight, which give you an idea how little power you get from that area of solar cells. Add to that the need to store the energy onboard and the need for extensive retrofitting of planes, and the payback period is likely to be very very long. It doesn't seem like this would be worthwhile until you've already covered a lot of other easier surfaces with solar panels.

@justicenature:

I know this isn't exactly what you mean, but it does use the principle of converging the sun's light rays to a single location.
It's a pretty cool and environmentally friendly way of generating power.

http://news.bbc.co.u...e/nature/6616651.stm

Thanks zentropy - very interesting. After reading that i'm guessing that focusing rays of light from a group of mirrors onto a single spot is either more cost effective and/or more efficient in producing energy than using a similar group of king size concave len's that direct the light to a single source.

I'm guessing that may have something to do with the cost of a group of giagantic concave lens hanging from two very high column's !! or that its simply scientifically ridiculous !

Solar in this case would most likely not be the way to go for generating power to sell back to the grid. However, if you were to add Sterling engines to the output of the waste heat from the jet engines you could certainly generate a huge amount of power to store in batteries. It all comes down to size and weight. The surface area of the plane would not be enough to give you any real returns, however they are working on paints that act like photovoltaic cells. Those wont be around to the public for a while. Sterling is the way to go. Check them out on wikipedia. Good luck and good thinking.

You'd expend more energy flying the extra weight of the panels than the panels would generate.

Try adding them to static things -- such as large shopping mall roofs.

The FAA would require millions of dollars in engineering tests before you would even be allowed to apply this to any aircraft. The addition of PV's to any aircraft is a big ball of red tape and more than likely would not profit.

solar panels and there batteries are very heavy. It would cost more energy just keeping them in the air then they could ever possibly gain power.

Thanks for trying but I guess you didn't know that air planes generate power though wind power, as air pass though the jet engine the terbium creates power. So the byproduct of the trust powers the aircraft.

Nice idea in theory, but:
The generators on an A380 kick out 600kW of electical juice;
The wing area of the A380 is an impressive 845 square metres;
The solar intensity in the outer atmosphere is 1350Watts per square metre;
845*1350 = 1.1Mega Watt;
The best thin solar panels I've seen on prototype wings are around 20%, giving you 230kW. Only about 40% of the planes generator capacity.
If the the technology matures to a point where the panels are 55% efficient then you should break even (ignoring the added weight of the panels of course ;-) ).

It seems to me that the cost of the extra fuel you would use from transporting all that extra weight would far outweigh the amount of money an airline could make from generating electricity from one flight.

The most efficient solar panels to date can reach and efficiency of 42.8%

Source: http://www.udel.edu/...jul/solar072307.html