[DiogenesLamp]

Hydrogen internal combustion power is a still born looser. No one well informed takes it seriously as a solution.

I believe Hydrogen fuel cells are around 90% efficient. More than four times the efficiency of a typical car engine.

A 10% loss is not too much of a serious problem if you can get the power density you need for a transport fuel.

[dangerdoc]

PEM fuel cells, the ones being developed for cars are only about 40% efficient, doesn’t sound all that great until you compare it to the cars we drive now, only about 10% of the energy ends up moving the car.

[Texas Fossil]

Hydrogen Power Density> 0.00562 lb/ft³

Natural Gas Power Density> 0.044 - 0.0562 /b/ft³