Hydrogen Fuel Cells and How They Work
Hydrogen fuel cells are the new player in the area of alternative fuel and sustainable motoring. At the time of writing, there aren’t any production cars fitted with hydrogen fuel cell technology but there are a number of manufacturers that have plans to launch them at some point in the near future; Toyota , Honda and Mercedes are the most talked-about names in this department. All the same, there are a few vehicles already out there that have been rigged out with fuel cell technology, mostly as demo or concept vehicles.
The Toyota FCV concept at the 2013 Tokyo motor show: a fuel cell vehicle that we could see on the roads some day.
This is not to say that fuel cell technology hasn’t been tried and tested. It got its real launch (literally) back in the 1980s when NASA fitted them onto the Space Shuttle and the Apollo projects before that, as their space- and fuel-saving ability were very attractive for outer space missions. In fact, they were invented back in the early 1800s when scientists were starting to tinker around with electricity (cue conspiracy theories now).
OK, so how do hydrogen fuel cells work and how practical are they for the everyday motorist?
In a nutshell, a fuel cell is kind of like a battery. A fuel cell generates electricity, which can be used for whatever you fancy, including getting the engine and the other bits and pieces working inside a car. It generates electricity by the way the chemicals provided by the fuel interact with each other, again similar to what a battery does. However, unlike a battery, it only does this reaction when oxygen is fed to the system, meaning you can switch the process on and off.
A fuel cell consists of three main parts: the anode (the bit where the electrons that create the charge flow out of), the cathode (the bit where the electrons flow to) and an electrolyte for the charge to move through. Fans of sports drinks may recognise the term “electrolyte”. This is because you have dozens of electrochemical connections that are rather similar to a fuel cell in your body’s nervous system (they’re at work while you’re reading this) and an electrolyte is anything that creates positive or negative charge when added to water. There’s usually some way of getting the air to the system to get the reaction started.
A car fitted with hydrogen fuel cell technology is more or less an electric car, although the fuel cell needs to be topped up from time to time with hydrogen. The oxygen is supplied by the air we all breathe, so that’s not a problem.
You may wonder where they hydrogen goes if it needs constantly topping up. Is this creating some sort of exhaust? Technically speaking, it is producing a “waste” product that is a compound consisting of two hydrogen molecules and one oxygen molecule: H2O or good old water.
There are, however, a few downsides to hydrogen fuel cell vehicles. The first one is the lack of bowsers that dispense hydrogen. They do exist in some parts of the US so far, but they are rather rare. This is the biggest problem with the potential uptake of vehicles using this technology. Not only would you have to develop bowsers for dispensing hydrogen gas but you’d also have to find some way of getting the hydrogen gas from where it’s been manufactured to the pump, which would mean a whole new industry (come to think of it, this probably isn’t a bad thing – it’s getting started that’s the problem). This would mean a few logistics and health and safety issues, too: hydrogen is really, really explosive (ever heard of the Hindenburg disaster?).
The problem with setting up a whole new infrastructure for hydrogen technology contrasts with the situation with plug-in electric vehicles. We’ve already got the electrical network in place, so it’s a simple case of putting in a few more places to plug in, plus a few more sources of electricity if needed.
Hydrogen production isn’t an issue, though. At the moment, hydrogen gas is a by-product of quite a few industries, especially those to do with ammonia and methanol – and that’s just a few of them. Often, the process of turning the really nasty carbon monoxide into CO2 (which does have its good side) involves water donating an oxygen molecule to the pollutant CO, leaving hydrogen gas behind. You can also get hydrogen from ordinary water and from sea water (or waste water), so there are a lot of juicy possibilities for the future.
So what should the typical Aussie driver of today think about hydrogen fuel cell vehicles? At the moment, you’d probably do better with an electric or hybrid vehicle, as there aren’t too many places where you can grab hydrogen at this stage. However, when things get off the ground (and I mean “when” rather than “if”), they will be a good way of powering our cars as we go from A to B. I’m looking forward to it!
More information about hydrogen fuel cell technology and progress can be found at the following links:
- http://www.hydrogenaustralia.org/
- http://www.csiro.au/Outcomes/Energy/Gas-Processing-Conversion-Fuel-Future/Project—Hydrogen-and-synthetic-fuel-production.aspx
Happy driving,
Megan
Level 2, 9 Help Street