So I have been toying with the idea of building a hydrogen fuel cell car and using a fiero as the base. It would resemble a standard EV conversion but use a hydrogen fuel cell in place of a mountain of batteries. Well actually, there would need to be a couple batteries but only like 2. A hydrogen storage tank would go in the center tunnel in place of the fuel tank with the fuel cell in the front of the car. The compactness of the electric power train would free up much more trunk space on top of it. Sort of like the honda del sol's trunk. Easy right? Sort of...
The hydrogen storage tank would contain metal hydride. The way this works is the hydrogen forced into the tank bonds with the hydride and actually gives a greater storage density than liquid hydrogen! It doesn't need to be frozen and it isn't under pressure when stored. The way you release the hydrogen is by heating the hydride. That separates the molecules and slowly releases them in small amounts which is perfect for a fuel cell. Current fuel cell prototypes compress the hydrogen to over 5000 psi. They are able to get around 300 miles on a tank at 60 mpg. Theoretically using hydride could allow a range of over 1000 miles per tank.
The fuel cell would be of the PEM (proton exchange membrane) variety. I'm not going to go into detail how these work but the basic concept is hydrogen and oxygen are sent to opposite sides of the cell and the PEM in the middle allows the electrons from the hydrogen atoms to pass through the fuel cell to bond with the oxygen molecules which produces electricity. The only emission from this process is water vapor because H(hydrogen) and O(oxygen) combine to form H20. Fuel cells can be stacked in a series to produce more power. This is called electrochemical generation. The fuel cell stack required with current technology would be about the size of a spare tire but could become smaller as technology advances. Unfortunately current PEM fuel cells use platinum in their construction making cost an issue. Alternatives to platinum are currently being researched. The fuel cell required to run an electric motor in this application costs about $3,500 online.
So far not too complicated. Now comes the tricky part. How do we generate hydrogen on a large scale? That has been really the main roadblock with this technology. It is the main reason we aren't living in a hydrogen economy. There are several ways of extracting hydrogen but I believe a process called electrolysis is the way to go. Electrolysis is the process of splitting molecules with an electric current. You can actually do it at home with a bowl of salt water and a battery. You can also extract it from natural gas which is the way the majority of hydrogen is produced. This won't work in the future because we will run out eventually. The reason electrolysis isn't used currently is because it is significantly slower and not nearly as efficient.
Despite that, I feel it is still the best option. A fuel cell can actually be run in reverse to produce hydrogen and oxygen. In that application they are called "electrolyzers". Another type of fuel cell, called a solid oxide fuel cell, actually doesn't use any platinum at all. The reason you can't use this type in cars though is because they need to be heated to a very high temperature to function. But they would be perfect for stationary hydrogen generation! They become more efficient as they get hotter. In fact, at 2500 degrees Celsius water will split without any electric current at all! The power required could be supplied by solar, wind, and hydroelectricity and just produce hydrogen constantly.
In this application, hydrogen isn't so much a fuel source as it is an energy carrier. For example, solar power doesn't produce enough current to drive an electric car without the solar panel being absurdly large. Even then it would only work during a sunny day. In a car you need a lot of energy and you need it quickly. That is what hydrogen is good for. Most people only drive their cars less than an hour at a time. Then it just sits there for 90% of the time. That is why you use solar, wind, and hydroelectric power for hydrogen generation instead. It can run 24/7 and easily produce enough hydrogen to power our cars the short time we drive them every day.
Now back to the solid oxide fuel cell... As I said before the process is more efficient the hotter it becomes. The problem is it takes huge amounts of energy to reach those high temperatures. In fact it would be stupid if not impossible to reach 2500 degrees Celsius using conventional means like heating coils. However, I think I found an unconventional solution in my garage.
Plasma! Using high voltage DC power in water (250 volts at 12 amps in my experiment) will rapidly split the water molecules and then recombine them. This produces a huge amount of heat and after 2 minutes something magical happened. I reached 2500 degrees Celsius. The water in the jar began to put off a white glow and the water became calmer. The variac I was using was showing float which means the reaction was giving off energy.
Here's what happened... The high temperature was able to split the water and the electric spark recombined them which produced more heat and kept the reaction going. At this point I was able to turn it down to only 20 volts. This was the minimum I could get spark and keep the reaction going. Some claim this to be cold fusion but it is not. This is high voltage electrolysis. I am still putting more power into it than I am getting out but it isn't much more. This releases superheated steam that can be sent to the solid oxide electrolyzer at near optimal temperature. So how hot did it get? I'm not sure. But it was hot enough to melt the stainless steel electrode.
And that ladies and gentlemen is how I think we will solve the energy crisis. 20 volts at 20 amps is all the energy we need to hold the temperature we need to extract the hydrogen from the water. An amount of power easily produced by solar.
This project will take years but I think it will be worthwhile. I kind of like the idea of building the car of the future in a 30 year old GM sports car.
[This message has been edited by RilesOfSmiles (edited 07-28-2013).]