Problems With Hydrogen Fuel

Hydrogen

• Hydrogen is a common element, but it isn't available in large quantities by itself. It links together with other elements, and to get hydrogen, separation from the companion element has to take place. Water is an example. In water, there are two molecules of hydrogen and one of oxygen. To separate water into separate molecules by electrolysis, more energy is required to isolate the hydrogen than the hydrogen produces for fuel. Because of the power required for separation, it becomes impractical for use as a fuel.
  
  

Fuel Cells

• Sir William Grove made the first fuel cell in 1839. In the 1960s the fuel cell was designed to produce electrical power for various spacecraft. The operation consists of a polymer electrode sandwiched by a cathode and anode. The hydrogen atom splits into a proton and an electron and take different paths to the cathode. The electrons go through a circuit that produces electricity. When the hydrogen and oxygen recombine, it produces water for drinking and other uses on the spacecraft. For this system to work on a production basis, supplies of hydrogen need to be more readily available than current conditions. To be economically feasible, the cost of hydrogen production would have to fall by 10 times.
  
  

Energy Potential

• Hydrogen has a high unit of energy per mass, but a low energy density when compared to the same volume of gasoline or other common fuels. To use it to power an internal combustion engine would produce less horsepower and shorter driving ranges. To produce the same range would require approximately three to four times more hydrogen. Liquid hydrogen is about a quarter less dense than aviation fuel, which means it produces less power per volume.
  
  

Supply and Storage

• Tanks that store pressurized hydrogen are very heavy. A tank that holds 6.6 lbs. of hydrogen would weigh over 800 lbs. It can also leak into the metal and cause metal fatigue. Liquefied hydrogen is impractical for automobile and home use. Hydrogen liquefies at -253 degrees Celsius, which requires a lot of power to get it liquefied. When liquefied, it requires a great deal of insulation to keep it liquid, which adds to the tank weight.