Hydrogen cars and alternative energy

I pasted this from http://forum.physorg.com Please help with abbreviations and make comments.

Hydrogen takes up a lot more room than a gallon of gas does.

then there's the question of how do you keep H2 liquid, and in a car for a week at a time? how big of a tank will you need to store enough H2 to drive the car for 300 miles?

how do you get the H2 from the pump at the station to the car? can we still self serve? what will leaking H2 into the atmosphere do to the environment?

there's more questions I'm sure. I really don't think Hydrogen is the answer everyone is looking for. I think the answer is two fold, possibly more.

First, build lots of thermo depolymerization plants and turn the bulk of our garbage into nice clean oil. this solves 3 problems right off the bat. 1. less garbage 2. less dependence on foreign oil and 3, no new carbon being added to the environment, since we're just using carbon that's already in the cycle.

Second, build lots of pebble bed nuclear power plants.

so the oil runs our cars, and the nuke plants run our houses and offices. we can also increase solar and wind and wave. huge barges off the coasts with wind mills on them would do wonders. Also I'd like them to start researching Microwave transmission of power again. so we can put up giant solar collectors in orbit and beam the power to the ground, and Giant solar farms on the moon.

this way we don't have to destroy our entire gas infrastructure, and we get a cleaner environment to boot. 35 MJ/kg 32 MJ/kg 0.11

LHV gasoline 32 MJ/kg * 3.727272727 kg/US gal = 119.2727273 MJ/gal

Actually 1 kg H2 is a bit better than 1 gal gas.

All the rest is nonsense. BMW and Linde are already in process of building 400 liquid H2 auto fueling stations all over Europe. Their stations have a robot attendant to fill you up, you don't even leave your car. Using liquid H2, the auto range, though lower, is not a problem.

Mass density Energy density
H2 0.07 kg/litre 8.4 MJ/litre
Gasoline 3.73 kg/litre 119.36 MJ/litre

Note that LH2 is significantly more tank-effective than CNG, which all taxis in my area now use for fuel. Need better numbers? Get a hybrid. Using NREL's high-pressure carbon fiber liquid H2 tank design the storage retention time is not an issue. (eg by Chart Indust. stated NER% for their smallest tank, a 13 kg auto tank should only need to have used/evaporated 70 grams per day starting on the third day. Plan ahead. Or better yet, use a Plug Hybrid based on ACPropulsion's inverters and grid-connect the vehicle if it's going to sit idle for any time period. It can then start up once or twice a day to generate power back into the grid to cool down the tank, and use the grid to charge some small Li-ion batteries needed for regen braking anyway, to reduce further it's fuel requirements with off-peak windpower or those pebble beds etc..)

Bio-diesel is a curiosity, but should be reserved for aircraft (which can't arbitrarily shorten re-fueling stops or be quickly re-designed for LH2). Once those are done, then is there any left? And please carefully eval. the gabage burning idea, way too many heavy metals which can't reasonably be separated except from flue gases in large centralized incinerators.

I have to say that site didn't do much to convince me.

all I got out of it is that fuel cells are only about 35% efficient and they are expensive.

so I'll have to pay more for a car, and probably higher maintainance for it.

and this doesn't tell me how much H2 I'll need for my 300 mile trip, it's easy to tell people to plan ahead, but people don't and frankly they don't want too. you'll never convince any large group of people to accept something that's going to make them work harder or be inconvienced. People in general just don't care.

so if you want to really sell this, it either has to be cheaper, which I don't think it would be. the initial cost of the car will be more, and I'm betting the cost of the fuel will be more. It has to be easier, which it could be, but I'm betting it won't be. the cost of maintaining those robot pumpers is going to jack up the price and will probably take longer to pump, which is bad when you didn't plan ahead and have to fill up before work and you over slept and you're running late.

though that is something Id like to learn more about.

How much is H2 going to cost at the pump? how will it be made, how much can we make, how much will it take to give a comparable range to the car. how much will the cars cost. and how much will it cost to keep the car. how much re training will he have to have and how long will it be before we have enough competent mechanics to meet demand? and how much more are we going to have to pay them?