Quote:
Originally Posted by Frequitude
Not asking. We know where we can get it from. You have to make it. You either run electricity through water (and you have to make the electricity too) or you reform hydrocarbons (kicks CO2 into the atmosphere and you still need to produce the damn hydrocarbons people complain about in the first place). There's other methods too, but they all have one common theme...you have to spend a tonnnnnnnne of resources to produce a small amount of hydrogen.
Then there's the fact that no distribution network currently exists. Think of all the gas stations, pipelines, fuel trucks, etc. there are in the world. Then think of how much money that would cost to create an equivalent hydrogen distribution network. Many zeros.
So basically, we have to make it and we have no way of getting it to the consumer. It's great that it only makes water when you burn it, but it is very very far from practical.
|
Actually, you don't have to spend a ton of resources to produce hydrogen. Modern Electrolyzers along with a good gas compressor (to get pressure high enough to useful levels) is 75% efficient. That is, 75% of your input electricity will be stored in compressed hydrogen. Then you get 50% of that when you put the hydrogen in your fuel cell. Not as efficient as an electric car, but far more efficient than conventional ICE's.
Shantz brought up the major benefit of hydrogen is that something like the Volt gets you a 60 mile range, whereas the range of the hydrogen car is much closer to that of gasoline.
In terms of distribution tech, since electricity is the only thing that you need in order to generate hydrogen, it would be very possible to have portable electrolyzers that you plug in at night to refuel your car. I'm sure there's other ways to distribute hydrogen that won't require a million km's of pipeline but I guess I'm not quite visionary enough to find out what it is.
Now, I'm not saying that this is viable. It's not, due to current tech limitations as well as cost. However, there are ideas out there, and depending on how far battery tech gets vs. hydrogen, it is possible that hydrogen would come out to be the winner. For example, if it was possible to build current hydrogen cars for 1/5th their current cost, it would easily be the best option available. I guess we will have to wait and see.
Edit: I noticed I'm throwing out a lot of #'s without backing it up, but here's a start:
http://www.hydrogenics.com/assets/pd...%20Leaflet.pdf
4.8kWh/Nm3 of hydrogen roughly translates to 60% electrolysis efficiency including all the pumps and compression. It seems I was a bit optimistic when I said 75%.