MEMES
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Lighter than air ideas.
As we know, oil is dirty. It stinks. It causes horrendous pollution, and spawns multi-billionaires ( who have a penchant to create wars etc etc. ) .
Largely because of the reinforcement of air-pollution laws, but also because of governmental pressure, all the major motor companies are currently testing prototype hydrogen powered vehicles. There are already vehicles available, and hydrogen filling-stations in various countries – following Iceland’s lead.
Consumers like the idea because the exhaust from a hydrogen powered engine is mostly water. The manufacturers like the idea because the current engines can be easily modified to run on H2. ( The other method uses so called fuel-cells, which are essentially H2 > electricity converters.) So, all in all, the ‘hydrogen economy’ looks like a great idea. There are however, two problems. Two very big problems unfortunately.
Firstly. How do you generate the hydrogen in the first place ? The obvious way is to get it from water – but, because hydrogen is such a reactive element, it takes a lot of energy to separate it from it’s preferred partner, oxygen. The energy needed is usually supplied in the form of electricity, which of course has to be generated somehow. Most of the global electricity supply is currently coming from oil / gas fired power stations – and nuclear stations. There will have to be an awful lot more of these facilities in the world to supply the H2 for a global transport system. The pollution / security problems for these stations is of course very well known.
So, the idea that H2 vehicles won’t pollute is a myth. They just shift the very visible source ( your car’s exhaust pipe ) to a largely invisible one ( a giant power-station somewhere ). Of course, it would be possible to use ‘green’ electricity sources, such as hydro, wind power, wave power, solar panels etc. But at the moment, in most parts of the world, their contribution to electricity supplies is marginal.
( note * there are several other methods for producing H2, but all need very large energy input. The most common commercial method derives hydrogen from – guess what – fossil fuels, especially coal ! Hence the great interest from countries which have large coal reserves – but dwindling oil supplies. Any countries spring to mind ? )
The second problem also has to do with hydrogen’s chemical reactivity. It burns. The NFPA ( national fire protection association ) rating for hydrogen is 4, the highest danger-rating they’ve designated. In fact, in under normal conditions it burns so fast that, in effect, it often explodes. A hydrogen fire is not like a petrol fire. It’s really, really, dangerous stuff. Also, because the H2 molecule is so small ( the smallest in the universe as far as we know ), it leaks out from just about any container. It’s been estimated that around 10% of the gas would leak out if a true ‘hydrogen economy’ was in operation. That means an awful lot of extremely nasty accidents. An overturned and leaking petrol tanker on a motorway would be a harmless inconvenience compare to a similar tanker full of hydrogen. Traffic accidents would shift from a crash>possible-fire scenario to a crash>guaranteed-explosion one.
It’s very hard to see how a solution to these problems will be found. If the H2 could be produced solely by ‘green’ electricity generation, that would help. But then, why not just store the electricity in batteries and run electric vehicles ? The safety issue might be solvable, say, with an H2 absorbing gel which only releases the gas on demand – but that hasn’t been invented yet.
Back to the drawing board.
