The solar powered airship, why don't we see them?

[rhinochopig]

Reading the thread on Global warming got me thinking about alternative, low environmental impact transport.

The question is, why do we not have Airships for freight and personnel transport? Googling the subject suggests that a solar powered airship is quite feasible and probably safer than a jet aircraft.

Obviously a lack of speed is a critical issue, but is that such a big problem when compared to the benefits? Personally, I would happily swap getting to, say New York, in 6-8hrs for more spacious accommodation and a travel time of 1.5-2 days, and because it is a more environmentally sound method of transport should attract government tax breaks. The concept of slower, but much cheaper transport seems appealing, plus it ticks the environmental boxes.

So why haven't we seen them, and would you use one?

[funkyrobot]

rhinochopig said:

Reading the thread on Global warming got me thinking about alternative, low environmental impact transport.

The question is, why do we not have Airships for freight and personnel transport? Googling the subject suggests that a solar powered airship is quite feasible and probably safer than a jet aircraft.

Obviously a lack of speed is a critical issue, but is that such a big problem when compared to the benefits? Personally, I would happily swap getting to, say New York, in 6-8hrs for more spacious accommodation and a travel time of 1.5-2 days, and because it is a more environmentally sound method of transport should attract government tax breaks. The concept of slower, but much cheaper transport seems appealing, plus it ticks the environmental boxes.

So why haven't we seen them, and would you use one?

We haven't seen one because its like everything else that is 'friendly' to the environment, it doesn't use fuel that is taxed to the hilt!! You could imagine the outcry if (and when?) the government started trying to tax sunlight and wind!!

[MartG]

To carry any serious cargo, and thus be competitive with existing planes, an airship would need to be as big as a supertanker - and would be a bugger to control in stormy weather

[s2art]

Back of a fag packet calculation suggests that a solar powered airship would move at a relative snails pace. So thats weeks to get there without some other form of propulsion, assuming the wind is in the right direction.

[ewenm]

Because we don't see the sun...

[GreenV8S]

Freight is usually heavy, and airships aren't good at heavy.

[mechsympathy]

rhinochopig said:

a travel time of 1.5-2 days

London - New York is about 3500 miles....

[rhinochopig]

s2art said:

Back of a fag packet calculation suggests that a solar powered airship would move at a relative snails pace. So thats weeks to get there without some other form of propulsion, assuming the wind is in the right direction.

Hindenburg took 3 days from Franfurt to NY.

Modern solar panels, as proposed to be fitted to the geostationary telecoms ships, are capable of 400kw power generation, which coupled to low emission diesel-electric power system could provide plenty of power. Couple this with modern aerodynamic design, should increase the speed over the Hindenburg.

The useful lift of the Hindenburg was 112 tons.

[Parrot of Doom]

Have you seen an airship just for people? They're massive, and don't carry much. And they take ages to go anywhere. And solar panels don't last long.

[gopher]

GreenV8S said:

Freight is usually heavy, and airships aren't good at heavy.

1000 ton capacity airship skycat mind you I'm not sure it exists yet.

[rhinochopig]

GreenV8S said:

Freight is usually heavy, and airships aren't good at heavy.

CL160 will carry 160 tons

http://en.wikipedia.org/wiki/CL_160

C5 Galaxy 81 tons

Edited by rhinochopig on Friday 30th May 14:22

[JuniorD]

ewenm said:

Because we don't see the sun...

Above a few thousand feet it's always sunny (except at night)!

Edited by JuniorD on Friday 30th May 15:26

[rhinochopig]

mechsympathy said:

rhinochopig said:

a travel time of 1.5-2 days

London - New York is about 3500 miles....

So what is the point you are making. At 100mph in 48hours you can go 4800miles In 1937 the Hindenburg could do 84mph.

[Davi]

JuniorD said:

ewenm said:

Because we don't see the sun...

Above a few thousand feet it's always sunny (expect at night)!

which could be considered a bit of an arse when you are only 1/4 of the way across the atlantic by the time night falls...

[s2art]

rhinochopig said:

s2art said:

Back of a fag packet calculation suggests that a solar powered airship would move at a relative snails pace. So thats weeks to get there without some other form of propulsion, assuming the wind is in the right direction.

Hindenburg took 3 days from Franfurt to NY.

Modern solar panels, as proposed to be fitted to the geostationary telecoms ships, are capable of 400kw power generation, which coupled to low emission diesel-electric power system could provide plenty of power. Couple this with modern aerodynamic design, should increase the speed over the Hindenburg.

The useful lift of the Hindenburg was 112 tons.

And how much would 400KW of solar panels weigh? BTW thats a stload of panels, at approx 100W/M>2, you would need 4000 square meters of panel.

And the Hindenburg had approx 4400 Horsepower, about 3200KW. So to equal its power you would need something like 30,000 square meters of panel. Weighing what?

Edited by s2art on Friday 30th May 14:45

[mechsympathy]

rhinochopig said:

So what is the point you are making. At 100mph in 48hours you can go 4800miles In 1937 the Hindenburg could do 84mph.

That's a maximum of 84mph, not the cruising speed. Has airship technology improved much since then? I expect the cruising speed might have improved, but aerodynamics plays the biggest part so I wouldn't have though the maximum is much higher.

Even if it does only take 1.5 days, who's prepared to spend that time unnecessarily cooped up in a small cabin.

[rhinochopig]

mechsympathy said:

rhinochopig said:

So what is the point you are making. At 100mph in 48hours you can go 4800miles In 1937 the Hindenburg could do 84mph.

That's a maximum of 84mph, not the cruising speed. Has airship technology improved much since then? I expect the cruising speed might have improved, but aerodynamics plays the biggest part so I wouldn't have though the maximum is much higher.

Even if it does only take 1.5 days, who's prepared to spend that time unnecessarily cooped up in a small cabin.

But that was my original point, with that sort of lift capacity you wouldn't be restricted to a cramped cabin. The Hindenburg was quite luxurious. You could design something more akin to cruise ship accommodation. I'm suggesting an airship could replace the jet aircraft, but as a complementary means of transport to one that is going to get very expensive very quickly if oil prices keep rising...

With regards to speed - who knows. I would have though we could get an airship cruising at 100mph at high altitude given the advances in aerodynamics. Just raising the operational ceiling would give huge improvements due to less air resistance.

In response to S2Art

What has made the HALE project possible is the radical improvement in photovoltaics, i.e. solar cell technology. The traditional solar cell is a single crystal semi-conductor deposited onto glass, which is efficient but heavy and expensive. The HALE airship would use instead amorphous silicone solar cells deposited onto a Kapton (polyimide) film. The thickness of the solar cell itself is less than 800 Ångstrom and although this cell only has 8% efficiency it costs a fraction of the former cells and will revolutionize the extraction of electricity from the Sun in the future.

http://www.lindstrand.co.uk/hale.html

So not that efficient, but very very light.

Edited by rhinochopig on Friday 30th May 14:49

[s2art]

rhinochopig said:

mechsympathy said:

rhinochopig said:

So what is the point you are making. At 100mph in 48hours you can go 4800miles In 1937 the Hindenburg could do 84mph.

That's a maximum of 84mph, not the cruising speed. Has airship technology improved much since then? I expect the cruising speed might have improved, but aerodynamics plays the biggest part so I wouldn't have though the maximum is much higher.

Even if it does only take 1.5 days, who's prepared to spend that time unnecessarily cooped up in a small cabin.

But that was my original point, with that sort of lift capacity you wouldn't be restricted to a cramped cabin. The Hindenburg was quite luxurious. You could design something more akin to cruise ship accommodation. I'm suggesting an airship could replace the jet aircraft, but as a complementary means of transport to one that is going to get very expensive very quickly if oil prices keep rising...

In response to S2Art

What has made the HALE project possible is the radical improvement in photovoltaics, i.e. solar cell technology. The traditional solar cell is a single crystal semi-conductor deposited onto glass, which is efficient but heavy and expensive. The HALE airship would use instead amorphous silicone solar cells deposited onto a Kapton (polyimide) film. The thickness of the solar cell itself is less than 800 Ångstrom and although this cell only has 8% efficiency it costs a fraction of the former cells and will revolutionize the extraction of electricity from the Sun in the future.

http://www.lindstrand.co.uk/hale.html

So not that efficient, but very very light.

Ok but at only 8% you would need maybe 60,000 sqaure meters to match Hindenburg output (less if operating at the equatore with auto orientating panels, more weight for that though)
Can see an aerodynamic design that allows 60,000 sq meters of panels on an airship to get good orientation.

[rhinochopig]

s2art said:

k but at only 8% you would need maybe 60,000 sqaure meters to match Hindenburg output (less if operating at the equatore with auto orientating panels, more weight for that though)
Can see an aerodynamic design that allows 60,000 sq meters of panels on an airship to get good orientation.

The solar power available at 70,000 feet is over 1kW/m2 and with an 8% efficiency this will translate to 80-watt electricity per m2. The airship’s total surface area is 30,000m2 , so only a small percentage needs to be covered by solar cells to achieve the required daytime power extraction of 400kW.

The design in the article is a similar size to the Hindenburg. Besides, if you read my follow-up post I mentioned that you could use modern diesels to supplement any shortfalls (or fuel cells as discussed in the article linked).

The point I was trying to make without getting into an argument, is that there doesn't seem to be any huge show stoppers for why we don't make use of airship technology. I suppose thinking about it, the low cost of air-travel has meant that there has been no economic driver to.

[mechsympathy]

rhinochopig said:

But that was my original point, with that sort of lift capacity you wouldn't be restricted to a cramped cabin. The Hindenburg was quite luxurious. You could design something more akin to cruise ship accommodation. I'm suggesting an airship could replace the jet aircraft, but as a complementary means of transport to one that is going to get very expensive very quickly if oil prices keep rising...

With regards to speed - who knows. I would have though we could get an airship cruising at 100mph at high altitude given the advances in aerodynamics. Just raising the operational ceiling would give huge improvements due to less air resistance.

Luxury weighs more though. As far as speed goes, what if your airship hits a headwind?

I'm sure it could be done, but who'd use it? Business travellers would't have the time and most holiday makers wouldn't be prepared to waste 3 of their 14 days on travel.