Fuel of the future: why hydrogen could be the answer to all our prayers
Sorry, Tesla, but batteries might just be the new Betamax
These days, it feels like the internal combustion engine is taking quite a battering. Global warming, nitrogen oxide, particulates, cancer, dwindling natural resources... At any given moment, the humble engine is being pilloried, slandered and blamed by activists, media and governments.
Car manufacturers are justifiably worried about the future of this technology, which has served us well for more than 100 years, and they're scrabbling about in search of a solution.
The ambitious entrepreneur Elon Musk would have you believe that battery-powered electric cars - and more specifically HIS battery-powered electric cars - are the way forward, but I think hydrogen is probably a better bet. Here's why.
Different but the same
Although electric vehicles (or EVs, for short) and hydrogen cars sound completely different, they are actually very similar.
Both use electric motors to power the wheels, so they don't make much noise, they don't emit any carcinogenic gases from their exhausts and they offer maximum torque right across the rev range, which makes them very responsive to throttle inputs.
Hydrogen fuel cells are essentially in-car power stations that mix hydrogen and oxygen to create electricity and water vapour.
However, while a standard electric car will use batteries to store its power, hydrogen cars have a tank full of hydrogen and something called a fuel cell, which converts hydrogen into electricity. Think of it as an on-board power station that emits water vapour, rather than carbon dioxide.
Sounds complicated. Why is that better?
Basically, the biggest problems with electric cars are nothing to do with the cars themselves, but with getting electricity to the car.
Certainly, range is no longer a problem - the EPA reckons you can get 335 miles from the latest Tesla Model S 100D - so the real catch is that it takes a long time to charge. Assuming you're using a standard UK 13-amp/240-volt plug, the Tesla Owners' Group website says that filling an 85kW Model S takes between 24 and 30 hours. A 110-volt US supply will take even longer.
If that's a wait you can do without, then you can charge up faster with Tesla's Supercharger network, but even then you'll spend more than an hour drinking naff coffee at a service station before the battery is completely full.
Even at a Tesla Supercharger, EV charging can take a while...
With hydrogen, on the other hand, you get much the same range as a battery-powered electric car, but filling up takes about three or four minutes.
The other issue is battery life. Lithium-ion batteries currently have a fairly short lifespan - mobile phone and laptop batteries, for example, wither and die after just a few years - and EV batteries use much the same technology. Nissan reckons the cells in its entry-level Leaf will last for at least five years or 60,000 miles, but after that the available range will start to tumble.
Hydrogen tanks, on the other hand, don't wear out. They don't get tired and lose capacity after every fill-up - they just keep on holding hydrogen.
Filling up with hydrogen is a quick and simple process similar to filling a petrol car.
But what about infrastructure?
Because of all the fuss surrounding electric cars, charging points have been springing up all over the place of late, but hydrogen filling stations are somewhat less numerous. According to the US Department of Energy, there are just 39 in the whole of the USA, and the vast majority of those are in California.
However, while this an issue for the few hydrogen cars on sale today, it needn't be a problem in future. You see, hydrogen is dispensed using a pump vaguely similar to those used for filling petrol cars, and the filling station can store the gas under the forecourt, as it does with petrol.
Even if you only modified every other fuel station to have just one hydrogen pump, running a hydrogen car would suddenly become incredibly feasible.
At the moment, hydrogen filling stations are few and far between, but the pumps aren't that dissimilar to petrol stations.
Admittedly, that's a big job and it wouldn't be cheap, but we've got to consider the ramifications of electric cars, too. Building charging points everywhere and upgrading the electrical supply to drivers' homes (which would be a necessity for the majority of us) is not something you can do with a small change.
Sounds great. Now where do we get all this hydrogen from?
Well, I've got good news and bad news on this front. Firstly, the good news...
Hydrogen is the most abundant element in the world, and any you use in your car can, theoretically, be re-used.
When a fuel cell creates electricity, the hydrogen is mixed with oxygen to produce water vapour - that's why you hear people say the only emission from a hydrogen car is water. That's a good thing because a) water is not a particularly harmful substance, and b) water is a good place to get our hydrogen from.
Hydrogen is the most abundant element on the planet, but it's normally attached to other things, such as oxygen.
And the bad news?
Hydrogen may be abundant, but it's pretty firmly stuck to other things and getting the hydrogen on its own often takes a lot of energy.
One way of producing hydrogen is to run an electric current through salt water, which causes the hydrogen to bubble away, but that uses up electricity that could otherwise be used in your fridge. Or a Tesla.
Another popular method is to mix steam with methane at a very high temperature, but this uses a lot of energy to heat the chemicals, and the whole process produces carbon monoxide as a by-product.
At present, then, isolating hydrogen is not brilliant for the environment, but there are carbon-neutral ways of getting at it, such as powering the reaction with renewable energy and using landfill gas to react with the steam.
So why do you think hydrogen is the answer?
Good question. You see, getting our hands on hydrogen is difficult and requires energy, but much the same accusation can be levelled at electricity. Or indeed petrol.
The USA currently uses around four trillion kilowatt hours of energy per year, but if all the country's cars were Tesla Model S 100Ds, the demand would probably increase by something in the region of 1.2 trillion kilowatt hours - or about 30 percent.
Producing enough energy to power a world of electric cars would be a huge undertaking.
However, we might soon be able to produce enough hydrogen to power our cars without needing anything like as much extra power. Scientists think that the next generation of nuclear power stations will produce enough heat and steam to isolate hydrogen without producing much more electricity.
Of course, nuclear power has its drawbacks, and these reactors aren't set to go online until at least 2020, but it's an immensely powerful possibility.
Do you agree that hydrogen is the answer to replace the internal combustion engine? Let us know in the comments.