I was curious, so I looked it up.
NiMH battery - 1 MJ/l
Hydrogen (gas@5000psi) - 3 MJ/l
Hydrogen (liquid) - 8 MJ/l
Gasoline - 32 MJ/l
The numbers change when you factor in the storage technology overhead, but the ratios are still about the same.
Hydrogen is much more energy dense than gas when you compare by weight, but weight doesn't seem to be the limiting factor. Volume does.
NiMH batteries are what the Prius has in it. GM has a 10,000psi compressed hydrogen van and a liquid hydrogen van. Their fuel cell is 1.6 kWh/l, or 5.5 MJ/l.
http://www.gmeurope.com/marathon/2/popu ... liquid.htm
http://www.gmeurope.com/marathon/2/popu ... ressed.htm
The liquid hydrogen van has a range of 250 miles. The main problem is making the tanks big enough and cheap enough on a production car.
Costwise, my calculations suggest that hydrogen will be about the equivalent of paying four bucks per gallon of gasoline, assuming you do coal-powered electrolysis. If you get your hydrogen from methane or do your electrolysis with cheaper energy, that number goes down.
comparison of various automotive energy sources
Pretty sure you mean compressed natural gas.quantus wrote:The van shuttles at the airports here are all required to be hydrogen powered from what I found out. It's kinda annoying since they now charge like $20 or $30 more
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- Tenth Dan Procrastinator
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I stand corrected. Thanks for the link, I've been meaning to look that up.Martin wrote:Pretty sure you mean compressed natural gas.quantus wrote:The van shuttles at the airports here are all required to be hydrogen powered from what I found out. It's kinda annoying since they now charge like $20 or $30 more
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http://www.amminex.com/index_files/Page344.htm
http://www.dtu.dk/English/About_DTU/New ... C2CF1A7%7D
Hey hey hey! 13 MJ/l! I'll buy a car running on that.
http://www.dtu.dk/English/About_DTU/New ... C2CF1A7%7D
Hey hey hey! 13 MJ/l! I'll buy a car running on that.