Hydrogen Fuel Cells

A simplified explanation of a hydrogen fuel cell is that hydrogen is channeled to the anode on one side of the cell and oxygen from the air is channeled to the cathode on the other side. The anode has a platinum catalyst which splits the hydrogen into positive hydrogen ions (protons) and free electrons. Between the anode and cathode is a membrane which allows only protons to pass through it. The electrons are thus forced through an external circuit, powering the vehicle (or whatever), after which they return to the cathode. There, they recombine with the protons that have passed through the membrane to again form hydrogen, and then combine with the oxygen from the air to create water (H2O). (See The ECO Guide to Careers That Make a Difference, Island Press, Washington, 2004, p. 203.)

Vehicles powered by hydrogen fuel-cells thus produce what can be drinkable water (used by astronauts) as their only “waste product,” along with some heat, which can be utilized in other ways. They also promise the possibility of doubling as miniature power plants when parked at home, where the owner could sell the power they generate back to the local electric utility company, thus partially defraying the cost of owning the vehicle. Or, perhaps such a vehicle could be used as part of the power-generating machinery for an off-the-grid home itself, although obviously another source would be necessary when the vehicle was out on the road (unless it was able to keep the home’s batteries sufficiently charged between trips). Another advantage of fuel cells is that they have no moving parts and do not involve combustion, so they should be far more reliable than current internal-combustion engines (see this Wikipedia article).

Hydrogen is by no means the only substance that can power fuel cells, but it offers great promise because it essentially produces no pollution. Currently though, a major problem is how to derive that hydrogen fuel, which is not an existing energy source like fossil fuels – it must be “made.” It can be “cracked” from natural gas or methane, for example, or electrolyzed from water, but those processes themselves require the use of energy. However, if that energy can be derived in the form of solar- or wind-generated electricity, then the entire process can be essentially emissions-free and environmentally-harmless.

There is also the issue of the danger involved in storing hydrogen, an extremely flammable gas. And for use in fuel cells, it can be stored at pressures of up to 10,000 psi. But the various difficulties currently involved with fuel cells seem worth dealing with, because the general concept offers so much promise.

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