Tag Archives: transport

Hydrogen cars are the wrong solution

http://www.thesundaytimes.co.uk/sto/ingear/cars/article1209612.ece says that the UK government has produced a report saying that 1.5 million hydrogen cars will be on UK roads by 2030.

Hydrogen cars are part of the future that falls firmly in the category of ‘can do but shouldn’t do’.

I don’t doubt that hydrogen could be manufactured and sold from special filling stations to be used as fuel for fuel cells to make electricity to drive cars, or maybe even used in a modified internal combustion engine, or directly burned to make steam for a steam engine. It can. I don’t even doubt that the government is entirely capable of legislating subsidies for ridiculously expensive and inappropriate solutions just to appease lunatic fringe pressure groups. They are already doing so for wind turbine farms and rooftop solar panels, so why not hydrogen cars. It would just be another shovelful of idiocy on what is already a huge pile. What I do doubt, because I am a futurologist and an engineer, is that it makes any sense.

Hydrogen was once seen in futurist circles as the fuel of the future, for a year or so anyway before anyone did the analysis properly. When they did, they noticed:

Burning hydrogen (even in a fuel cell) produces water as the main product. Water is a greenhouse gas, a much more powerful forcing agent than CO2. It may be condensed by the car, but even then, at least in dry weather,  the water will evaporate from the road surface and enter the water cycle. It acts as a greenhouse gas until it becomes rain again. If it is raining already, the water produced will probably be a harmless addition. Hydrogen cars will therefore have a small but possibly significant effect on the water cycle, weather and climate, just as regular cars do, and probably not that much different. They certainly can’t be assumed to be in any sense environmentally neutral.

Hydrogen needs special containment systems to make it safe, and these are likely to add significantly to the cost of a car.

Fuel cells are still very much more expensive than competing power sources and there is little sign of any imminent major progress.

Making hydrogen generally requires electricity, and it is really just a proxy for the electricity used in its manufacture. It would be just as easy, as cheap, and much safer to just deliver this electricity direct to the cars without going through the hydrogen stage. Electric cars will have batteries and some potential synergy using them as storage for intermittent renewable energy manufacturing such as wind farms. If we are going to have to put up with wind farms anyway, then the economics shift in favour of this approach.

Also, development of new materials and supercapacitors, together with new directed induction technology (that allows large distances between the inductive components), allow for a Scalextric approach to car powering. It is hard to see the point in using an intermediary like hydrogen when this would be a better solution.

I don’t know where the pressure has come for government to think down this path. But it is the wrong path and they should change direction before they waste yet more money on inappropriate, expensive and inefficient infrastructure.

Could graphene foam be a future Helium substitute?

I just did a back-of-the-envelope calculation to work out what size of sphere containing a vacuum would give the same average density as helium at room temperature, if the sphere is made of graphene, the new one-size-does-everthing-you-can-imagine wonder material.

Why? Well, the Yanks have just prototyped a big airship and it uses helium for buoyancy. http://www.dailymail.co.uk/sciencetech/article-2257201/The-astonishing-Aeroscraft–new-type-rigid-airship-thats-set-revolutionise-haulage-tourism–warfare.html

Helium weighs 0.164kg per cubic metre. Graphene sheet weighs only 0.77mg per square metre. Mind you, the data source was Wikipedia so don’t start a business based on this without checking! If you could make a sphere out of a single layer of graphene, and have a vacuum inside (graphene is allegedly impervious to gas) it would become less dense than helium at sizes above 0.014mm. Wow! That’s very small. I expected ping pong ball sizes when I started and knew that would never work because large thin spheres would be likely to collapse. 14 micron spheres are too small to see with the naked eye, not much bigger than skin cells, maybe they would work OK.

Confession time now. I have no idea whether a single layer of graphene is absolutely impervious to gas, it says so on some websites but it says a lot of things on some websites that are total nonsense.

The obvious downside even if it could work is that graphene is still very expensive, but everything is when is starts off. Imagine how much you could sell a plastic cup for to an Egyptian Pharaoh.

Helium is an endangered resource. We use it for party balloons and then it goes into the atmosphere and from there leaks into space. It is hard to replace, at least for the next few decades. If we could use common elements like carbon as a substitute that would be good news. Getting the cost of production down is just engineering and people are good at that when there is an incentive.

So in the future, maybe we could fill party balloons and blimps with graphene foam. You could make huge airships happily with it, that don’t need helium of hydrogen. 

Tiny particles that size readily behave as a fluid and can easily be pumped. You could make lighter-than-air building materials for ultra-tall skyscrapers, launch platforms, floating Avatar-style sky islands and so on.

You could also make small clusters of them to carry tiny payloads for espionage or terrorism. Floating invisibly tiny particles of clever electronics around has good and bad uses. You could distribute explosives with floating particles that congeal into whatever shape you want on whatever target you want using self-organisation and liberal use of EM fields. I don’t even have that sort of stuff on Halo. I’d better stop now before I start laughing evilly and muttering about taking over the world.

Future of bicycles

Recycled blog from http://nvireuk.com/

Bicycles occupy the peak of the moral high ground as far as environmentalism is concerned because once they are built and delivered, ongoing emissions come almost entirely from the human riding them. While they are certainly good for the environment overall, the picture isn’t quite as clear as is sometimes portrayed and there are some places where the use of bicycles may not be environmentally sensible.

On proper cycle paths, they are certainly a good solution from both a fitness and environmental point of view (hopefully even once the environmental costs of making the cycle paths and the bicycles are factored in). But when mixed with car traffic, they can be very dangerous, with bicycle riders suffering many times more casualties per mile than car drivers. They also force other vehicles to slow down to pass them, and then to accelerate again. On busy narrow roads, this can often cause significant traffic jams. The bicycle may not be directly the cause of the extra consequent emissions from the cars, but from a system wide view, the overall CO2 produced would likely have been less had the cyclist driven a car instead, so this must certainly be taken into account when calculating the impact. The carbon costs of the extra accidents, with the resultant traffic jams and so on, should also be factored in. Accidents have a very high carbon cost as well as a human one.

It won’t take long until almost all cars are driven by computer. By the mid 2020s, we will have a lot of automatically driven cars and substitution will accelerate quickly. These cars will be able to travel much closer together, freeing road space both length and width-wise. This means that more car lanes or wider cycle lanes could be provided. With computers driving the cars, far fewer bicycles would be hit, if any. It is therefore likely that bicycles could be much safer to ride in the future, and because they can be more readily separated from car flow, will be more environmentally friendly, although this advantage is greatly diminished for electric cars. Improving the technology for car transport therefore makes cycling even more environmentally friendly too.

A decent cyclist can ride at 7.5m/s on the flat, less uphill and a bit faster downhill. Suppose that on the tough sections, there was a conveyor belt moving at 7.5m’s. This would reduce overall journey time and the problem of arriving very sweaty at the other end. It would also reduce the speed differential between cyclist and passing traffic, making it safer to ride. With a conventional conveyor belt, this looks a ridiculous idea, because the first falling leaf would clog the system up, rain would cause havoc, cars encroaching onto the path would cause mechanical stress because of the speed differential between a conveyor and the road surface, and pedestrians would also try to step onto it and cause yet more havoc. The idea is a non-starter.

Linear induction motors though can propel metal without using moving parts (apart from the metal being propelled of course). Suppose we add a metal plate to the bike, close to the road surface, and put linear induction motors in the cycle lane.  With no moving parts in the conveyor, there would be no problem with clogging, rain, cars or pedestrians.

Many roads have good electrical supplies along them in ducting or even more accessibly in street lighting. If it can be developed cost effectively, this would be a good way of encouraging cycling as a viable transport solution, and reducing carbon production, with beneficial effects on health too.

The cycle lane itself could comprise a heavy duty rubber mat that could be simply rolled out overnight along a roadside and plugged in to the electric supply. This would be easier than having to paint a new path. It can be rolled out piecemeal according to demand. On the bike, there would be a cheap metal plate attached to the front forks so that the bike could be pulled along. It can easily be designed to deflect easily if it hits debris on the surface, so that the cyclist isn’t threatened.

The amount of extra force given to the cyclist could be variable. Bicycles could be given RFID chips to identify them and the personal tastes of that cyclist indulged alongside billing. Some people might want lots of assistance or to go very fast, other want less assistance or to go slower. Since induction plates can be individually controlled, and the bicycle plates can also be tweaked for height or inductance, it is easily customisable in real time.

Mechanical energy is very cheap, whereas the effort required to cycle long distances or up hills is a strong deterrent to many potential cyclists – they are not all super fit! Given the human body’s poor efficiency in converting food into mechanical energy, it is likely to be very competitive in emissions terms even for cycling, let alone compared to using cars.