Seeking an Airship Expert! (also, alternate fuel sources)

Hydrogen makes quite a good fuel, if you can contain the explosive force. Mix it with oxygen and a spark, and you get BOOM + water, which the airship can disperse as "rain".

It also has some history of use in airships, as a means of making them lighter-than-air.

You could also coat the entire surface with a solar cell compound, to get electric power.

You can get the spark from static electricity somehow generated from the motion of the airship through the air.
Look up "hydrogen fuel cell."

Didn't somebody put a bunch of solar panels on the top of an airship once?

I'd say a combination of solar panels and hydrogen fuel cells to power the motors. Keep in mind that the more weight you start toting around, the larger your balloon has to be to compensate if you want to be able to take the same payload. If you really want to go crazy, put a nuclear reactor on the thing and you can stay up virtually indefinitely. It's going to come with a big weight penalty, as reactors are heavy and require a lot of heavy piping and shielding, and whether the passengers would appreciate that is a matter you'll have to decide. But you could do it.

In terms of size, I'd say that if you're willing to allow for some improvement in lightweight materials you could get up to about 1,000 feet long or a bit more (the Hindenburg was just over 800). Just an educated guess though.

I've always loved airships, and have read a great deal about them, including an English translation of a German operational manual for the airship Bodensee (LZ 120).

Airships are usually lifted using hydrogen or helium, although some efforts at hot air have been attempted. The problem is, hot air has only a fraction of the lifting capacity of these other gases, with hydrogen being about 8% lighter than helium. Therefore, an airship using helium needs to be at least 8% larger than one built for hydrogen in order to lift the same amount. However, the added size means increased air resistance, which means more powerful engines, more fuel, etc.

An airship relying on hot air would have to be significantly larger than one lifted with either gas. The lifting power of hot air is entirely dependent on the temperature of the air inside the ship compared to that outside the envelop. Also, a very large amount of fuel would need to be carried. One possible thermal option would be to use heated helium in order to increase its already potent lifting power. Some large amount of fuel would still be needed, although waste heat from the engines might be used.

Certainly, the best option for a hot air airship would be a non-ridged design, since this is lighter.

Many fuels have been employed for airships. The famous Graf Zeppelin employed a concoction called blau gas, which was neutrally buoyant but caused other problems. Being future fiction, you can always make up something similar, just as you can come up with fancy super-light materials or gases.

I'm sure you can find plenty of information poking around on the internet. Have fun!

Cover the top with retractable shades that can be used to change the envelope color between black and white. Use black during the day to absorb heat from the sun, and white during the night to minimize radiative cooling.
Don't know if that could do the whole job of keeping it up, but it would reduce fuel requirements anyway.

You could use alcohol for fuel. Or charcoal.

Thanks so much guys! Lots of great ideas here, and helpful X3 (I can be a total 'tard when it comes to physics 8D;)

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