Canadian Company Plans Solar-Powered Heavier-Than-Air Airships 218
savuporo writes "By crossing airships with airplanes, Solar Ship is planning to build a craft that can carry heavy loads long distances with a tiny carbon footprint. Filled with helium, they soak up rays from the sun to provide the energy for forward motion and fulfill its original design challenge – carry 1,000 kilograms (2,205 lbs) of payload 1,000 kilometers (621.4 miles). The craft is heavier than air, and uses a combination of helium filling its interior and its lifting body delta wing shape to stay airborne. Solar Ship shows plans for a range of different size craft for different duties."
Re:A bit short sighted (Score:3, Interesting)
Shoot. Prior art from the 1600s. http://en.wikipedia.org/wiki/Vacuum_airship [wikipedia.org]
Re:A bit short sighted (Score:4, Interesting)
Short answer: no.
Longer answer:
It's very difficult to achieve a vacuum in the first place. If there is even the slightest leak the air will be rushing in with the force of a one atmosphere pressure difference. With a lighter than air gas the pressure difference is quite low and any leak can be handled with a periodic "topping off" to keep out the air. Even if we had the technology to produce a "vacuum ship" it would not likely be cost effective since the lift gained by a pure vacuum is very small compared to that of helium or hydrogen gas.
An envelope that held a vacuum for lift would be under considerable forces. There is the force of holding back the outside air. There is the force of the gondola which carries the cargo. There would be wind, birds, stupid rednecks shooting at it, among other things that would try to punch holes in it or rip it up. It's just not practical.
Re:is there a helium shortage? (Score:2, Interesting)
I believe that some helium /does/, in fact, escape the Earth, because it's so light that it can break free of the gravitational field. (At least, I believe that that's the principle in play.) http://en.wikipedia.org/wiki/Atmospheric_escape
A stupid concept... (Score:5, Interesting)
The difficulties with a solar powered helium dirigible are manifold and have already been pointed out -- finite supply of helium, helium needed for kids' balloons and (eventually, perhaps) as thermonuclear fuel (at which time we'll kick ourselves for wasting it for decades in kids' balloons), absolutely impossible to keep sun-warmed helium inside any sort of bag. Weather and wind make the transportation dangerous or impossible (given the wimpy peak power likely to be available to move the bag -- probably inadequate to overcome even a very modest headwind). The danger of 1000 kg loads being dropped on people's heads if weather conditions exceed the limited capacity of robot brains to solve weather problems and the lifter breaks up, pops, catastrophically fails.
It isn't quite inconceivable that one could build a solar-solar system -- a solar balloon for lift, solar power for "thrust" -- although again I think that the force of wind pressure instantly will exceed the peak thrust of any onboard solar system on even a very sunny, nearly still day. To lift a metric ton you'll need a rather large balloon, so very small overpressure on the upwind side will exert a huge force downwind. And you'll still have the problems with weather, with the fact that the sun doesn't shine at night and you can't carry batteries or the whole design becomes laughably impossible, not marginally feasible (either one, Helium or hot air).
But rail? Piece of cake. Hell, you could probably deliver a steady stream of pickup truck sized loads driven by solar collectors along the roadway -- 70-100 watts per square meter of collector, plenty of room for 1000 watts per meter of actual track along the 1000 km route. In fact, the track (with a mere 12 meter wide roadway, 2 meters of which is track and vehicle) will generate anywhere from 100s of megawatts to a gigawatt of power on any reasonably sunny day. Assuming 10 kW per metric ton to move payload at 100 km/hour or better, one can move anywhere from a minimum of 10,000 metric tons up to a maximum of 100,000 metric tons per 10 hours of useable daylight day, for the amortized capital cost of the solar powered roadway. (Don't whack the math too much, these are all estimates and YMMV). The cost of the solar electrification is currently a bit over $1/watt, installation and collection will double that. Call it a $5 billion project (the cost of a couple of weeks in Iraq), build it on an existing rail corridor between (say) Detroit and Chicago square in the heart of the industrial heartland. If one charges $10/ton for transport (pretty cheap, one would think) it grosses close to $1 million/day running the rail at capacity, $300 million a year, payback of the initial investment in 15-20 years.
As is so frequently the case in solar projects, this is maddeningly close but not quite a cigar. For a billion dollar investment it would be a no brainer -- payback in 3 years (more likely 5 with operating costs), pure profit thereafter. For 2 or 3 billion dollars it is attractive -- an effective yield of maybe 5-10% on investment in the long run. For 5 it is right down there at 1-3% yield, implying a fairly long period to wait for a not-too-large ROI, plenty of risk. Drop the cost of solar cells by one more factor of two and it will happen all by itself. Drop it by a factor of four or more, which is entirely plausible given sufficient volume in the market (and this project alone would consume