Opinion

Fuel Cells may be the answer but what is the question?

Peter Horszowski 

Nobel Laureate, Carlo Rubbia, turns and uses his hand to indicate a mark about 1 metre above the floor. "That," he tells us, "is the oil equivalent of each year's solar energy." He explains that recent calculations shows that the sun gives our globe the energy equivalent of a metre's worth of oil. On every single spot. Every single year.

Now, as awful as it would be to live immersed in oil (as the unfortunate penguins can tell you following the Exxon-Valdez spill) there are distinct energy advantages. You could have as much energy as you wanted exactly when you wanted it, simply by combusting the required amount of oil. You can't do that with the sun's energy because you only get limited amounts for a limited time. The problem with any form of renewable energy has always been quantity and availability. It is fine in principle but how exactly do we get it to boil our tea and run our cars? Well, that is where fuel cell technology comes in.

A fuel cell is essentially a battery, a sophisticated and environmentally friendly way of storing and supplying energy. In a hydrogen fuel cell hydrogen and oxygen gases are kept alongside one another. Conventionally, these two volatile gases are burnt to harness their energy. (Oxygen is used as rocket propellant and, more terrestrially, hydrogen is combusted instead of petrol for vehicle propulsion, such as in the BMW H car.) But a fuel cell doesn't burn anything; it works more like a marriage counsellor, encouraging the hydrogen and oxygen to get together into a familiar phenomenon, known to everyone as water. The way they get together is quite clever, really.

The heart of the fuel cell is the proton exchange membrane (PEM). Charged and acidic during the reaction, our friendly marriage counsellor becomes like a burly nightclub bouncer. Hydrogen gets oxidised at the electrode known as an anode generating protons (H⁺) and electrons (e^-). The PEM repels the electrons and only lets the hydrogen protons through the door. Disgruntled electrons have to go round the back. Now a flow of electrons is another familiar phenomenon, known to everyone as electricity. That is where you position your energy hungry device, or load: right in the path of the flowing electrons. Hydrogen which is allowed to pass through the PEM then combines with oxygen to form harmless water. 

The system is perfectly reversible too, so that when the two gases are happily married as water molecules, they can then be separated out again, using the selfsame Proton Exchange Membrane. Of course, such a painful separation requires powerful coercion, so you need an external source like a solar panel. Once the elements are separate again, they can come together to supply energy as and when required, solving the problem of quantity and availability. It is noiseless, efficient, and has no pollutants. Cool, huh?

So what is the problem? Not the technology. 

A fuel cell is one of several genuinely workable options for storing and converting renewable power. As Prof Rubbia elaborated, even large tanks of hot water are effective. But the hot air of political rhetoric is not as effective. As much as we talk about renewable energy, we haven't seen any real changes at all. With perhaps less than 30 years of fossil fuels left, consumption is at a rate unparalleled in the history of civilisation. Most of us go ahead, blithely confident that scientists and engineers will come up with something in the nick of time. But here's the scary thing. They already have. 

The problem is neither with the source nor the technology to harness it. It is us. Our star, the sun, gives us plenty. But we persistently refuse it. It is no use waiting for the scientists, because they have done their bit. We are the problem. We have to change and we have to do it now before it is too late. The fault, dear Brutus, lies not in our stars, but in ourselves.

Fuel cell technology can be used to power small electronic devices to motor vehicles. A range of suppliers can get you started off. In South Africa, you can start yourself off on a concept car  with reversible hydrogen fuel cell and detachable solar panel start at around R1,450.00. 

More information:

  Please contact Peter Horszowski at peter@pert.co.za (011)882-1435 www.pert.co.za and www.h-tec.com

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