Hypothetically, if as of tomorrow no cars were on the road except for zero emissions fuel cell vehicles what kind of infrastructure would be needed? Would there need to be a a whole new generation of mechanic? can you “sup” up a fuel cell vehcle? how do they refuel? Would we go to war with Canada for their water? How exactly do these cars work?
A fuel cell is just a fancy battery that generates its electricity by oxidizing any of various fuels, such as alcohol, methane, or hydrogen. The rest of the vehicle will be little different from any other electric car in production today.
The problem is, for hydrogen (fuel cell) powered cars to be viable, you need a solid infrastructure of hydrogen ‘petrol stations’.
For building these stations to be a profitable venture, you need a significant number of fuel cell driven cars on the roads. Catch 22.
-Oli
That’s a good catch.
Actually, the real problem with fuel cells (in my opinion) is that we expend more energy making the “fuel” than what we get out of it. While this might be O.K. for powering automobiles, fuel cells will not replace our intrinsic fuel sources (e.g. coal, gas, oil) as some people claim. (Unless efficiency is greatly improved.)
One proposal is to have the hydrogen generated in giant wind farms in remote locations. Or tidal farms in the Bay of Fundy or Mont St-Michel or something. Aside from strong NIMBY resistance, this could in principle work. Then you would need all the infrastructure besides. So far, they haven’t even decided what is the best form to store the hydrogen is. A simple one is in compressed gas bottles. Another is in the form of lithium hydride and there may be others. In any case, this would add a lot to the weight of the vehicle.
One of the easier ways of producing hydrogen is through breakdown of, er, hydrocarbons, which sort of puts you back where you started. Without large improvements in the efficiency of hydrogen extraction, it’s going to be very difficult for fuel-cell vehicles to compete with gasoline or diesel internal combustion on an economic basis.
As to how they work, the latest issue of Car and Driver has a couple of interesting articles on prototype fuel-cell cars, one from Honda, the other from GM.
Yeah, a fuel cell is just another kind of engine – it burns hydrogen rather than gasoline or coal, but you still need to get the fuel from somewhere. There are devices that turn gasoline (or methanol, etc.) into hydrogen, so it’s quite possible that you could build a fuel-cell car that fills up with gasoline just like an internal-combustion car. In which case, you wouldn’t need any more infrastructure, but you’re still burning gasoline and creating greenhouse gas carbon dioxide.
So what’s the advantage of a fuel cell? Well, it creates much less smog-type pollution than an internal combustion.
Also, it can run on a wider variety of hydrocarbons, so you can use other sources besides refined petroleum (methanol, etc.).
And if you do build the pure hydrogen fueling infrastructure, then you can easily make hydrogen from electricity. You still need to get the electricity from something, but at least have the option of something less polluting and renewable, such as wind power, dams, etc.
A fuel cell could also use fuels like propane or methane, for which a well-organized distribution system already exists.
I read an article the other day (sorry, no link) that stated that currently, the cheapest source of hydrogen for fuel cells was a process that stripped the hydrogren from coal. So we would probably have to end up returning to heavy strip mining of coal if we wanted to mass-produce hydrogen fuel cells in the near future.
Yes, hydrogen is one of the most common elements in the universe. Yes, when you burn it you get heat and water. But it simply doesn’t exist as a free element in large quantitites on earth, and must be broken out of complex substances before it can be used. And the processes that can do that on a mass-market scale can cause a good amount of pollution on their own.
Of course, you can also argue that they could cut our dependance on foreign oil, and I won’t argue against that.
-lv
Isn’t the real point of fuel-cells that they are much more efficient than Otto-cycle IC enginces, even if ultimately they draw from the same fuel source?
Aside from infrastructure, fuel cells would probably be doable now were it not for the preciouse metals needed to manufacture them. Platinum is one of the more expensive metals needed, and it’s in short supply (high cost) now. Imagine if demand increased 100-fold in order to accomodate the auto industry!
Being that I support myself making gasoline fuel tanks, maybe the slow-going doesn’t bother me so much. 
I read recently – in Discover? Scientific American? one of those two magazines – that they have developed/are developing a fuel cell that runs on gasoline, with efficiencies far superior to internal combusion engines and with far less emissions.
On the other hand, IIRC, this new gasoline fuel cell is far more complex that your basic hydrogen fuel cell, requiring more platinum as catalyst among other factors.
Such sources simply do not provide enough power.
A few points things worth noting:
1> Most of the hydrocarbon fuels can be used in fuel cells. However, fuel cells which can handle higher hydrocarbons are not yet technologically mature.
2> The heart of the fuel cell is the catalyst and catlysts are very susceptible to poisons - Carbon Monoxide, Sulfur, etc. So a fuel cell that has been shown to run on propane will not run with your commercial propane. To use distillation cuts from petroleum crude, they will need elaborate cleaning to remove the poisons.
3> If hydrogen is manufactured and distributed, there is still the possiblity of formation of pollutants (and definitely that of CO2) at the production facility. However, there is a more likelihood of reducing emissions because the release location is one rather than a million cars.
4> Bio fuels are better for fuel cells because of the absense of sulfur (a catalyst poison).
Quoth LordVor:
When did we ever stop heavy strip mining of coal? You do realize that the bulk of electrical power in the U. S. comes from coal, right?
Would it be viable to make hydrogen with electrolysis, powered by nuclear power plants? How much water and how many reactors would we need?
No, not yet. Not until we get a much better energy resource, like fusion. I don’t have figures, but the generation of hydrogen from electrolysis is far too inefficient. I want to say something like 50%. That is, the energy you get pack when you recombine hydrogen with oxygen is 50% of the energy you used to generate the hydrogen in the first place. You would pollute MORE with an economy like this.
The most intruguing method of obtaining hydrogen that I have seen is from certain species of hydrogen releasing algae. They use sunlight to split the water atom. Genetic engineering might one day enhance this natural ability.
From my factbook on coal which I have written:
- In 2002, 54.7% of US electrical production was from coal (1870 billion kWh worth).
- By 2025, coal is expected to make up 2,703 billion kWh of US electrical generation, which is still estimated to be 50.9%.
- As of Jan, 2000, nearly half of all coal produced in the US was from open-pit (read: strip) mines West of the Mississippi (about 511 million tons). Overall, in the US nearly 60% of all coal produced is from surface mining. Worldwide, this figure is closer to 70%.
I’m re-reading the college paper I wrote on Hydrogen.
It takes 1/7th the amount of energy to electrolize hydrogen sulfide as it does to electrolize water.
Coal Gasification is the technology which will bridge the gap between fossil fuels and the hydrogen economy. Coal is heated to the point of combustion, but it doesn’t ignite for lack of oxygen. Instead it gives off gasses that undergo several reactions that eventually lead to methane and water vapor. We use this today to get natural gas. It supposedly can be easily modified to get hydrogen instead.
[/hijack]
For the OP.
Since there are several “fuels” that can be run through a fuel cell, we can’t really predict what the infrastructure would have to be. We hope that one day it will be hydrogen and not natural gas. But in the near future, it would probably be natural gas. The process is very similar to hydrogen. We like hydrogen because it is the most elegant solution. It is the cleanest burning, and it is safer than gasoline. (YES, THIS IS TRUE.) Hydrogen could be piped into our homes just as, well almost as easily as natural gas is today. Imagine filling up your car at home! Some people can fill their natural gas burning cars up at home today! The same corporations that give us oil today would be giving us hydrogen in the future. They have a vested interest in the future of our energy needs. They have the capital to invest in the research it would take to make fuel cell technology and hydrogen technology a reality. They are the natural choice in providing it for us in the future. They are not trying to supress the technology because fuel cells run with hydrogen would only make them richer.
Okay, yes, you would need a new mechanic, as far as the fuel cell and electric motors are concerned. The rest of the car would be the same.
A fuel cell is at its most basic a place that allows hydrogen to combine with oxygen. It provides the catalyst. Actually, it just gets the process started. You might have done an experiment in Chemistry class. Well I did. I forget how we got the hydrogen but we got this beaker with hydrogen in it, upside down of course, and we were told to put a long lit match inside the beaker. The thing would make a POP sound. H2 doesn’t immediately react with atmospheric O2, since both of those molecules are stable. You need something to get the process going. Once it begins it’s a self sustaining reaction.
Anyway, the “catalyst” (for lack of a better term) to make water vapor from hydrogen and oxygen is either a jolt of electricity, or heat. If you use heat, you get flame as a result. If you use electricity, then the energy released from the joining of hydrogen with oxygen is electricity. That is the basis for a fuel cell. Hydrogen and air (or pure oxygen) are pumped into the fuel cell, where they mix. The energy jolt is given (when you turn the key) and the reaction is begun. Then the water vapor is either released or hopefully captured. (We don’t want all of that extra water vapor being released needlessly.)
Anyway, now you have electricity and you use it to run electric motors, just like electric cars use today.