Oops, you are reading me wrong again. I said 30% looses not 30% efficient (it's 70% efficient) that makes about 50-60% total efficiency. Still this iswhy you probably won't see liquid H as a storage media for vehicles using FCs.
Jeremy Maus wrote: >You caught me, Peter. Thanks. > >If the electrolysis part is 70% efficient and the converting of gaseous H2 >to liquid H2 is only 30% efficient, then at best we have 20% efficiency. >Still, I think the 150-200 mile range is about it for H2 vehicles. > >This is significant. That is a lot of energy wasted just to store energy. >Batteries are much better at 70-90% efficient. > >Efficiency is a big reason EVs will survive. Whew, that was a tough one to >keep from being off topic. > > >Jeremy Maus > >-----Original Message----- >From: Peter VanDerWal > >You wrote that backwards. Electrolysis can be up to 90% efficient >though most systems seem to be closer to 70%. >Of course converting the hydrogen to liquid form looses another 30% or >so (energy). > >FWIW I've read somewhere that liquid hydrogen contains approx 1/4 the >stored energy of gasoline. Of course that's not really all that >meaningful, what counts is how much of the stored energy you can access. > Assuming you use FC and an Electric drivetrain...I believe current FC >are about 50% efficienct, gasoline ICEs are about 20% so by my math that >means a gallon of gas will take you about twice as far as a gallon of >hydrogen. > >Of course that's not counting the extra size and weight of a container >that can hold liquid hydrogen, etc. > >Jeremy Maus wrote: > >>When converting water to hydrogen with electrolysis you lose 90% of the >>electricity you put in. >> >>I think the first statement implies it takes 45KWhrs of energy to _make_ 1 >>gallon of liquid hydrogen. That 1 gallon of hydrogen contains 4.5KWhrs of >>energy. With 10 gallons you could have the 45KWhrs which should take you >>150 miles. 150 miles sounds right for the range limit of hydrogen fuel >> >cell > >>vehicles. >> >>Jeremy Maus >>Belleville, MI >>[EMAIL PROTECTED] >>http://www.emidget.info >> >>-----Original Message----- >>From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On >>Behalf Of Lawrence Rhodes >>Sent: Friday, August 30, 2002 5:17 AM >>To: [EMAIL PROTECTED] >>Subject: Got on the radio. Coast to coast AM. Subject:Hydrogen >> >> >>Well I found out that it takes 45KW to make one gallon of Hydrogen. I >>challenged the guest to compare electric to internal combustion hydrogen. >> >I > >>think he is a paid lobby for the car companies. So it would take 45Kw to >>run an internal combustion hydrogen car 25 to 35 miles. Wouldn't 45kw take >>the average conversion about 100 miles. If you were using a fuel cell >> >would > >>a gallon of hydrogen make 45kw to run your electric car? Can't seem to find >>anything in the archieves about how far a kw takes you. Lawrence >> >Rhodes.... > >> >> > > >
