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Flights of fancy – Part 4

August 26, 2016

In the first three parts of this series I mused about what might be done if there was a industrial-scale solar power plant driving the production of carbon nanomaterials rather than just trying to generate power.  I suggested that, with access to carbon-based nanofabrics we could create blimps of various sizes and purposes,  and balloon-and-tether based power generation and docking facilities for airships.  In this installment I make some guesses about what could be done with something larger than blimps – dirigibles.

Dirigibles are airships that have a rigid internal structure to their gas-filled envelopes.  The most famous airship is, regretably, the Hindenberg, which caught fire, exploded and burned in 1937.  The accident occured while docking, and it exploded because it was a massive construction filled with hydrogen, which, when combined with oxygen, burns incredibly rapidly.  There is still debate as to why it burned, but with modern materials and practices we could reduce the risks substantially.

The rigid structure of a dirigible makes it much easier to mount gondolas and other equipment to the envelope, and can be used to support far larger structures than any blimp.  A carbon-nanomaterial dirigible could, in theory, be enormous, much larger than the Hindenberg was, while also being far stronger.  Modern electric motors could propel an airship into significant winds – which was one of the downfalls of the previous generation of airships.

Between super-strong materials and a rigid interal structure, it would now be possible to explore far more effective shapes for airships – including shapes that can sport vast arrays of photovolaic cells on the airship’s upper surface.  It would be possible to create tremendous cargo dirigibles – possibly none large enough to rival containerships, but possibly large enough to start diverting some shipping from the transport truck fleets.

In my most excitable flights of fancy I imagine a fleet of vast airships that would work in the upper atmosphere, piloted by computers, that never land, but instead take hundreds of shipping containers from smaller, airship-shuttles, lifted on tethers.  These main cargo dirigibles require some maintenance, but no fuel, no hydrogen, and travel with the wind around the clock and around the world.  Imagine rows of airships encircling the globe at various convenient latitudes, taking on cargoes and handing them off again from shuttles, blown around the earth on the prevailing winds, and taking on any long-haul cargo.  This would create market dynamics similar to the rather strange ones we see today, where fresh fish are shipped to Asia from North American fisheries, processed in Asia and shipped back more cheaply than they can be processed locally.  I can imagine a world in which it is cheaper to ship something around the world than to send it a few hundred kilometers west (in the Northern Hemisphere).

Also imagine replacing cruise ships with dirigibles, just as they were in the early part of the 20th century, moving slowly relative to jets, but large and luxurious enough to attract tourists.

In part 5 of this series, I will expand on some of the ways that these materials could change the way we respond to natural disasters.

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Flights of fancy – Part 3

August 24, 2016

This series is an extended musing on what might happen with a really robust solar energy industry that, instead of trying to outcompete all of the other electricity providers, using the relatively low-cost energy, both heat and electricity, to create a product that otherwise is relegated to irrelevence because of scarcity – carbon nanotubes and nanowires.

I discussed blimps – airships without internal structure – as an application of carbon-nanofabrics, because of their great strength and light weight.

In this part, I will briefly explore the uses of carbon-nanomaterials in the construction of balloons and tethers.  Like blimps, a super-light, super-strong fabric can create a balloon that can be bigger than those currently employed as weather balloons, which loft very high in the atmosphere.

Currently, balloons are not used much because they lose helium (which is expensive) and fall back to earth, and they could be at their most useful very high in the sky, which means that they cannot be easily tethered to the ground, because the tether, if made with steel cables, would be so heavy it would drag any balloon made of conventional materials back down to the ground.
A carbon-nanofabric balloon, filled with stronger-lifting hydrogen, could be very large.  Large enough to support several key pieces of infrastructure – a moisture-capture mechanism of some kind, a suite of photovoltaics and you have a hydrogen-generating plant.  This way, as the pressure drops as hydrogen is lost through the balloon’s membrane, it can be replenished without coming down.  Also, a cable of carbon nanomaterials can be made incredibly strong without much weight.

So now we have a balloon that can stay high in the atmosphere, above most of the clouds (but not all, because then it wouldn’t be able to make its own hydrogen) and tied to the ground with an essentially unbreakable cable.  What is that good for?  This brings us to a neat feature of carbon – it is an electrical conductor.  In naturally occuring forms like graphite, carbon has a lot of resistance, so it is used for lighting elements, but early research with nanotubes and nanowires suggests that they can be quite efficient conductors.  So what we’ve got is a wire leading into the sky as a permanent installation, 12,000-20,000 metres long.  As the wind acts on this it pushes against it a bit, but if the balloon is lifting strongly enough it will resist the effects of the wind, and a huge amount of friction gets generated across the whole length of the tether.  This is do two things – one, it will create a very strong static charge – more free electricity.  Unfortunately, the other thing is draw lightning.  This is free electricity happening rather faster than easily managed.  However, we have spent a lot of time getting good at redirecting lightning that hits our power lines, so we have a temporary solution.  Ultimately though, we may be able to build capactity to capture lightning strikes and use them more productively.

So free power is one use, but there are many others.  Tethers could be used as launchers for gliders, blimps, and drones of all types.  A set of electromagnets could be wrapped around the tether, and use the same principles as a monorail to lift almost any payload (assuming a large enough balloon).  It could be used in the same way to bring blimps and dirigibles down, against their lift, so they wouldn’t have to power themselves down with their maneuvering engines, which would make them lighter and leave more lifting power for cargo.

A tethered balloon is a major hazard to navigation of air traffic, but it might be possible to put sensors along the length of the cable, and use stored electricity to “flex” the cable out of the way of flying hazards.

In part four of this series, I will discuss dirigibles – blimps with an internal frame structure – one of the most interesting applications of these carbon nanomaterials. 

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Flights of Fancy – Part 2

August 19, 2016

In Part 1 of this series I lay out the idea of a really large solar power installation which, instead of generating electricity for export, uses the power and heat for creating carbon nanowires, nanotubes and carbon-neutral synthetic fuels.

In Part 2, I am going to discuss a few products that are possible with these materials.

Carbon is very strong for it’s weight, and can be woven into lots of different materials – mostly very strong fabrics, and solids when combined with glue.  That is with irregular, randomly assembled carbon fibre.  Carbon nanotubes are extremely fine tubes of carbon perfectly arranged in long, regular chains.  These are vastly stronger than carbon fibre, because of their shape and the molecular bonds – these bonds require a great deal of energy to create – that’s why they are energy-intensive to make.  They also require tremedous energy to break.  Carbon nanowires are strings of carbon one atom wide – orders of magnatude smaller than any other material, and hugely strong.  With filaments like carbon nanotubes and nanowires, you can create massively strong cables and fabrics that are also lighter than anything else we create.

So what do we do with light, strong fabrics and cables?  Well, anything that we currently make with carbon fibre is an obvious candidate, like bicycle frames, auto parts and fighter jets.  These bind carbon fibre in glues and resins, because the carbon fibre is prone to destruction with any kind of abrasion, and because, compared to nano-materials, they are disorganized, they have limited lifespans, stretching out and breaking down over time.  What I think are the killer applications for these materials are blimps, balloons, dirigibles and tethers.

I am going to take these applications one at a time over the course of this series, and then posit some specifics that I think are interesting ways that it would change the lives of everyone, everywhere.  As an aside, changing the lives of everyone, everywhere is what science fiction is based on, but in business is called disruption, which puts some entities out of business and creates opportunities for others.

Blimps

A blimp is a non-rigid airship.  They are inflated by a gas of some kind which is lighter than air, so they rise, and they don’t have anything inside the envelope to provide extra structure.  A relatively small pod, called a gondola, with engines and steering mechanisms is attached to the bottom of a blimp.

Carbon nanomaterials can be used to build blimps that are much lighter than previously possible.  The maximum size of a blimp is set by how much pressure they can contain, so blimps can get bigger using carbon materials, and they bigger they are, the more they can lift.  Using super-strong nanomaterials for gondolas will help them increase their size too.

The big issue with blimps and other lighter-than-air aircraft is the choice of gas used to fill them.  There are really only two choices – hydrogen and helium.  Helium is much, much heavier than hydrogen, it is expensive and hard to find and replace.  However, helium doesn’t explode, so it is much preferred at the moment.  Hydrogen can be created with electricity and water, so any industrial-scale solar installation with a water source can generate any amount of hydrogen for free.  The “no-explody” part of blimps is largely an engineering problem – there will be some risk, but it can be minimized.

So what do you do with larger, lighter blimps?  Today they are used to things like surveillance – they can cover their upper surfaces with solar panels, use lightweight, high powered electric fans and they can stay up for a long, long time.  Remotely or robotically piloted blimps could be made to stay up all the time.  They are being sold right now to hover at 80,000 feet and watch over battlefields or borders, but they could do much, much more.  With a robotic pilot they can present much lower risk than human pilots, and they can more effectively do battle with they great enemy of airships – the wind.

A blimp, even a really large one, is not well-suited to bulk cargo because of the limits to their size, but they could do anything a helicopter can do, and do it more safely.  When a blimp loses power, it doesn’t fall out of the sky.  That means that you could use blimps as cranes in remote areas, in urban areas, for search and rescue, and for sightseeing.  They are limited in speed because of air resistance, but they could be made more streamlined with the stronger materials, and if we are able to make more powerful electric motors they could conceivably be able to navigate in extreme conditions.

Because they can use solar power to produce lifting gas and propulsion, it could be possible to ship a blimp deflated, set up its solar panels next to a water source, and within a relatively short period of time it could self-inflate and be ready to deploy.  Getting high-value, low-volume cargo like medicine to a remote area could be made much easier with a cargo vessel that can travel day and night without needing to refuel.  The surveillance-style drone blimps could also act as replacement communications infrastructure in the event of natural disasters, acting like a satellite relay for much lower-power transmitters, even arranging in self-organizing and self-healing swarms to provide cell phone coverage after all of the cell towers have been destroyed or disabled.
Imagine a remote village in Nunavut has a bear break into the pharmacy and destroy all of the medicine for a community.  A teaching hospital in Saskatoon could assemble the necessary medicines in a blimp-ready cargo pod, take it to the roof in time to be picked up by a robotic blimp sent from Regina only hours after the call for medicine, and it could be in town within a couple of days, even in difficult or impossible conditions for a heavier-than-air aircraft.

Part three of this series will be discussing balloons and tethers.

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