Task
Fuel cells can best be compared to the way batteries work. Energy is produced in a chemical reaction between the anode and the cathode. The substances that react together in the fuel cell are hydrogen and oxygen. PEM (polymer electrolyte membrane) technology uses gaseous hydrogen (H2) as fuel and converts it with oxygen (O2) from the air to pure water. Electricity and heat are produced by the reaction in the cell. In contrast to traditional internal combustion engines, coal-fired power plants, and nuclear power plants no poisonous, radioactive, or environmentally harmful by-products are produced or emitted. The only waste product is water. To achieve this, however, only renewable energy must be used to produce the required hydrogen. The open-circuit voltage of the electrical circuit in the fuel cell is 1.23 V. To produce higher voltages, fuel cells are positioned one behind another, like the batteries in a pocket flashlight, and then “stacked” on top of one another.