An alkaline fuel cell is a device that converts oxygen (from the air) and hydrogen (from a supply) into electrical energy and heat.
It’s chemically comparable to a battery that will provide electric power continuously, as long as you feed it with hydrogen and air.
There is only one by-product – water.
Excluding water, an alkaline fuel cell is a zero emission device.
Figure 1: Alkaline Fuel Cell
One major component of all fuel cells is the electrolyte. An electrolyte is a solution that is able to conduct electricity. In an alkaline fuel cell the electrolyte is an alkaline liquid: in this case, potassium hydroxide also known as KOH. The presence of the hydroxyl ions travelling across the electrolyte allow a circuit to be made and electrical energy can be extracted.