What is a Fuel Cell?

In a fuel cell hydrogen and oxygen are converted into electricity with heat and water as by-products. The process is not an ordinary combustion with a flame but a direct transformation of chemical energy into electrical energy. One way to think of a fuel cell is as an electrical battery where the charging is done continuously by the supply of hydrogen and oxygen. This makes it possible for the fuel cell to run continuously. You can read more about the way a fuel cell operates here.

Types
There are several types of fuel cells. Some can utilize natural gas (methane, CH4) and coal gas in addition to hydrogen. All fuel cells have the same basic structure, consisting of an electrolyte and two electrodes, just like cells in ordinary batteries. The fuel cell types are described in more detail here.

Applications
Fuel cells can be used on many different scales, from tiny systems that can power a mobile phone or a laptop, to megawatt power plants. Read more about the applications and prospects of fuel cells here.

History
The principle behind the fuel cell was discovered in 1839 but it took a long time for the cells to have practical applications. Here you can read more about the history of the fuel cell.