What is hydrogens eroei?

Question

I have been trying to research the viability of hydrogen as an alternative fuel, but I keep reading that its energy returned on energy invested ratio is too high. I am trying to find out what the eroei of hydrogen is, but I cant seem to find it anywhere. Can anyone provide the answer?

Answer 1

to make hydrogen you have input energy to break the chemical bond between the hydrogen and oxygen.

The most efficient way is to use a steam reformer.  in this process, natural gas is mixed with water at high temperatures and pressures.  To get to this high pressure temperature state energy is input into the system.  If the system is designed to make 100 units of energy in the form of hydrogen, the amount of energy contained in the natural gas id 200 units (actually about 211.3).  So, their is a net loss in energy, besides the huge and expensive equipment you had to build to contain the chemical reactions.

The other method of H2 production is electrolysis.  This time electricity is sent through the molecules to separate them.  Just like above, to get 100 units of energy in the form of H@, you need 250 units of electrical energy.  Then add in all the equipment...