A pollution-free electricity generation technology that is expected to compete with traditional methods of creating and distributing electricity. It is also expected to be used in electrically powered cars, trucks and buses. On-the-road testing began with prototype vehicles at the end of the 20th century. Self-contained fuel cell systems are also expected to power individual homes within 20 years.|
Like a Battery
Functioning similar to a battery, which uses electrochemical conversion, fuel cells take in hydrogen-rich fuel and oxygen and turn them into electricity and heat. The waste product is water. The hydrogen can be derived from gasoline, natural gas, propane or methanol.
The hydrogen, which comes into the anode side of the fuel cell, is converted into electrons and hydrogen ions. The electrons are repelled by the anode and flow to the cathode. The cathode accepts the electrons as well as oxygen, which combine with the hydrogen ions from the anode, and converts them into water.
The Energy Alternative?
Some predict this will be the largest, new industry of the 21st century, although there are many obstacles to overcome. It depends on which sources for hydrogen ultimately make sense. By itself, hydrogen is difficult to distribute and stockpile, and installing hydrogen pumps in every gas station would be a gigantic undertaking. Currently, Ballard Power Systems, Inc., Burnaby, British Columbia (www.ballard.com) is the largest company making fuel cells.
The core of this fuel cell comprises two electrodes (anode and cathode) separated by a polymer exchange membrane. Each electrode is coated on one side with a platinum catalyst, which causes the hydrogen fuel to separate into free electrons and protons (positive hydrogen ions) at the anode. The free electrons are conducted in the form of usable electrical current through an external circuit. The protons migrate through the membrane electrolyte to the cathode, where the catalyst causes the protons to combine with oxygen from the air and electrons from the external circuit to form water and heat. (Image courtesy of Ballard Power Systems.)