A fuel cell is a device similar in principle to a battery. It facilitates the union of gaseous hydrogen and oxygen (from the air) in a controlled manner. The aim is the efficient production of electricity that can be used to drive electric motors, that in turn will drive the wheels. The only ‘emission’ is water.

Every high school brat knows electrolysis; take a couple of electrodes wire them up, stick them into a suitable electrolytic solution and wham - hydrogen and oxygen start co llecting along the electrodes.

What the general populace, however seem blissfully ignorant of is the fact that by reversing this reaction and combining hydrogen and oxygen under the right circumstances, you land up producing electricity and good old H2O. Issac Asimov at his best, only difference being that this little bit of sci-fi is about to come true, sooner than you think.

At the heart of each fuel cell lies a wafer-thin plastic foil called the Proton Exchange Membranes (PEM) that is plated with the catalyst, platinum. The ion exchanger or the PEM allows hydrogen ions (protons) to pass through. The electrodes are a thin layer of graphite paper that cover the PEM and are gas permeable. On either side of the electrodes are a pair of graphite bi-polar plates, through which the hydrogen passes on one side and oxygen (from the air) on the other. When the two gases react in the presence of the platinum catalyst, electricity is produced. This feeds the electric motors which in turn spin the wheels, thereby moving the car forward. The only emission produced from this reaction is water, so pure that you can drink it. Boggles the mind, doesn’t it?

Fuel cells allow a staggering 80 per cent of the chemical energy locked away in the fuel to be transformed into electrical energy. Therefore as far as efficiency is concerned, the piston engine is not even in the same league.

That fuel cells will power the car of the future there is little doubt. Prototypes from DaimlerChrysler, Ford, Honda and GM are already cruising the roads and becoming more and more usable and practical. A couple of years ago, fuel cell-driven vehicles were normally large vans, but today Mercedes-Benz’s Necar 4 allows for a full complement of passengers as well as some luggage space. Currently, the undisputed leader in fuel cell technology is the Canadian company Ballard. How much of a technological advantage does Ballard have over its rivals? Well, for starters, it has DaimlerChrysler, Ford, Honda and Volkswagen all queuing up outside its gates for anything from equity in the company to less formal or binding contracts for the purchase of fuel cell stacks.

Way back in 1839 Sir William Grove of Oxford observed a reverse flow of current when he disconnected the power from an electrolysis experiment he was conducting. He realised that just as you could get hydrogen and oxygen using electrolysis, electricity could actually be produced by combining hydrogen and oxygen.

In 1932 Francis T Bacon of Cambridge built the first working example of a fuel cell-powered machine, a tractor, but due to the high cost of raw materials and chemically pure gases required, commercialisation was far away. In 1960 he transferred the fuel cell concept and technology to aviation giant Pratt & Whitney, and the fuel cells were used for the Apollo lunar missions. An improved version still powers the space shuttle. So all that money spent on space exploration was not wasted after all.

It is extremely difficult to digest the fact that technology like fuel cells remained dormant for almost a century. It’s just that the subject, until recently, hadn’t been researched or experimented with as much as the internal combustion engine. The difference between Sir Grove’s system and the Proton Exchange Membrane (PEM) fuel cells in use today, is the absence of the electrolyte. The PEM is a dry ion exchanger through which hydrogen ions can pass.