Alternate Powertrain
CNG/LNG
Vehicles that consume compressed natural gas (CNG) and liquefied natural gas (LNG) operate similarly to internal combustion engines that burn diesel or gasoline. The difference, however, is that the combustion of natural gas, of which methane is the most important component, is much cleaner, so that less harmful substances are emitted into the air, which means that CNG and LNG buses have a lower environmental impact.
Fuel Cells
The latest trend in alternative powertrains uses so-called fuel cells to obtain energy. We consider fuel cells to be electrochemical devices in which the chemical energy of the fuel (primarily hydrogen, but with certain cell types it can be other, e.g., methanol, ethanol, or biogas) is directly converted into electrical energy, while heat is also generated. After the introduction of hydrogen gas into the cellular system, hydrogen and oxygen react, and the hydrogen breaks down into protons and electrons. Protons combine with oxygen and water is produced. The hydrogen required for the operation of the fuel cell can be extracted from water, thus it is an easily accessible source of energy.
