Hydrogen Fuel Cells

By: Charles Brown

Hydrogen fuel cell technology promises to help us deal with the dwindling supply of fossil fuel. But how far away is this technology for you and me?

Aren't you tired of the high price of gasoline for your car? Not to mention your concern for the environment. Well, a solution to both of these concerns may be just around the corner. For years, scientists have being working on an alternative energy source that promises to change the way we live by changing the source of fuel for some of our most basic energy-using engines. This new technology is called a fuel cell, and it's based on using water as the original source of the fuel! A fuel cell provides a DC (direct current) voltage that can be used to power motors, lights, or any number of electrical appliances--including cars.

The technical name for a fuel cell is an electrochemical energy conversion device. You've actually been using one for many years, which is a battery. All batteries are electrochemical energy conversion devices.
But hydrogen fuel cell technology is a new twist on an old theme. Here's the basic idea of how it works:

A fuel cell converts the chemicals hydrogen and oxygen into water, and in the process it produces electricity. The difference between a simple battery and a fuel cell is that all the chemicals are stored inside the battery. The battery converts those chemicals into electricity but eventually it "goes dead" as the chemicals are used up. So you end up either throwing it away or recharging it.

On the other hand with a fuel cell, chemicals constantly flow into the cell. So as long as there is a flow of chemicals into the cell, electricity flows out of the fuel cell. Simply put, a fuel cell releases electrons from the hydrogen gas, creating electricity with the waste product being pure water! The electricity is used to power an electrical device--like the electric motor to run your car.

In an internal combustion engine, the gasoline engine burns gas and the battery converts chemical energy back into electrical energy when needed. However, fuel cells should do both tasks more efficiently.

This reaction in a single fuel cell produces only about 0.7 volts. To get this voltage up to a reasonable level, many separate fuel cells must be combined to form a fuel-cell stack.

One problem with using hydrogen is that it is not easily stored for consumer use. Other alternatives could be natural gas, propane, and methanol gas. But the primary objective of using fuel cell technology is pollution reduction. The fuel cell is also very efficient. Around 80% of the fuel used in these hydrogen fuel cells is converted into usable energy compared to only 20% for a gasoline powered engine and about 30% overall for a battery powered electric vehicle.

There is no question that the fuel cell holds great promise for the future. However, many challenges remain, and it's been predicted that hydrogen fuel cell technology won't be available for the masses until around 2050.

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