Comparing Types of Fuel Cells

[Skydude176]

I'm doing a project on fuel cells. Basically, I'm comparing the efficiency of a hydrogen fuel cell to a direct methanol fuel cell. I have two problems:

1.) I'm having some trouble figuring out how I should calculate the efficiency of each cell. Specifically, I'm calculating efficiency as (Output Energy of the Fuel Cell / Input Energy from the Fuel = Efficiency in watts). For the Hydrogen Fuel Cell, my Input Energy is simply the amount of energy I used to electrolyze the hydrogen from water. However, my Methanol Cell uses methanol in a prepackaged state, and it's not electrolyzed. How do I calculate the amount of stored energy in the methanol so I can calculate the INPUT Power in my equation?

2.) Due to technical limitations, each fuel cell has a maximum power output capacity. Even though I'm only measuring the Output Energy (in watts) of each cell (via a multimeter), will I need a different load for each of the two fuel cells to compensate for the output difference? Note: For my load, I'm planning to use a motor.

I would really appreciate it if someone could answer these questions. Thanks!

[paulsdecarli]

What chemical reactions are involved in the fuel cell? Seems to me that efficiency would be measured as cell-output-energy divided by the energy of chemical reaction. Yes, you do want to match the load to the source. A variable resistor might be the best load, although not as visually interesting as a motor, which could be powering a small winch lifting a load. Of course, with a motor, you have to consider motor efficiency, too.