One usually thinks of the electric car as one powered by batteries. Even a proposal to electrify Interstate roads would use the electric power to charge the batteries inside the cars. But there is another way of getting the electric power into a car: the fuel cell.
Fuel cells are like batteries in that they produce electricity by chemical processes; the difference is that in a battery the chemical energy is stored inside the battery, whereas in a fuel cell it is supplied from the outside by the fuels fed into it. More decisively, perhaps, a drained battery is recharged by electricity, whereas an exhausted fuel cell is revitalized by replenishing its chemical fuel supply.
Typically, one can combine hydrogen and oxygen to make water in a process that will produce two electrons per hydrogen molecule
¾and an electric current is merely the flow of free electrons through a conductor. (The process used in this type of fuel cell is the reverse of electrolysis, where an electric current will split water into its hydrogen and oxygen components.)Fuel cells are one of the oldest sources of electricity, going back to the early 19th century, long before Michael Faraday discovered electromagnetism
¾the principle by which all large-scale electric power is generated today. But they were primitive, and fuel cells came into their own only with the space program. The Apollo space flights, for example, used 15 kW fuel cells.There is a good chance that fuel cells can be developed into power sources for two major uses: for utilities and for automobiles.
The attraction for utilities is twofold. First, the efficiency of fuel cells is comparatively high and remains high even at light loads
¾ approaching 40% at outputs of only a few hundred kilowatts; and second, fuel cells respond rapidly to load demand changes. Neither point holds for steam or gas turbines.The first advantage also means that fuel cells could be distributed closer to consumers, resulting in smaller losses, since more energy is lost in transmitting electricity over transmission lines than gases through a pipeline.
To which one may add some other advantages, notably the almost complete absence of air pollution. The fuel cell produces mainly clean water, and if it were not for a tiny amount of sulfur dioxide, nitrous oxides and particulates, it would be as clean as a nuclear plant.
And since fuel cells are noiseless and virtually emissionless, their location in urban areas raises the possibility of utilizing their rejected heat for space heating and air conditioning.
Possible trouble lies mainly in the economics. The project we previously described (July 77) is now under way with a 4.5 MW fuel cell under construction by United Technologies, to be tested in a utility environment by New York's Con Edison.
[More: "A giant step planned in fuel-cell plant test," IEEE Spectrum, November 1978.]
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Vol. 8, No. 3
Newsletter: Access to Energy Newsletter Archive Volume: Volume 8 Issue/No.: Vol. 8, No. 3 Date: November 01, 1980 04:18 PM Title: Electing peace
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