Each simple fuel cell generates up to 1.23 volts. Individual cells can be wired together to produce greater voltages or higher current. The space shuttle, for example, has 96 individual cells arranged in three stacks. When hydrogen and oxygen are pumped into the shuttle's fuel cells, they generate 28 volts of direct current as well as heat and water. The heat is put to good use, vaporising the liquid fuels before they reach the fuel cells.
Water flows into storage containers for drinking and other uses.
Some different types of fuel cells Fuel cells are based on a simple principle. However, the chemical reactions involved do not occur readily. Unless special materials are used to construct the cells, very little electric current is produced. Much of the research with commercial fuel cells has focused on the development of suitable electrolytes. Phosphoric acid fuel cells , using acid as the electrolyte and fuelled by hydrogen gas, are the most commercially developed type of fuel cell.