FUEL CELL TECHNOLOGY: Pull out those old science books and dust off the table of elements. It's back to first year science class for the world of motoring. This is not a new phenomenon, set to loosen the grip of the big oil giants. The first fuel cell was built in 1839 by Sir William Grove, a Welsh judge and gentleman scientist.
Serious interest in the fuel cell as a practical generator did not begin until the 1960s, when the US space programme chose fuel cells over riskier nuclear power and more expensive solar energy. Fuel cells furnished power for the Gemini and Apollo spacecraft, and still provide electricity and water for the space shuttle.
And so to the science.
A fuel cell is an electrochemical device that converts chemical energy from hydrogen (or other fuel) and an oxidant into electricity. Electricity from fuel cells will power electric motors at each wheel of future vehicles.
The cells consist of a fuel supply (typically hydrogen), an oxidant (typically oxygen from air), two porous electrodes (anode and cathode), and an electrolyte (between the electrodes). A catalyst (e.g. platinum) speeds up reactions.
A single fuel cell is only a few millimetres thick. To power a vehicle, fuel cells are connected in series to provide appropriate operating voltage.
They can use fuel containing hydrogen, including methanol, ethanol, natural gas, and even gasoline or diesel. When using fuel other than pure hydrogen, a reformer or fuel processor is required.
The cells are a major advance from battery-powered cars, offering their advantages, but can also be refuelled quickly and can go longer between refuellings. What's more, using hydrogen as a fuel means zero emission vehicles, and those using other fuels would produce near-zero emissions.
When hydrogen is used as an energy source in a fuel cell, the only emission that is created is water, which can then be electrolysed to make more hydrogen.