Water is not a fuel. Hydrogen is not an energy source. It is a way to store energy made by some other means. You need energy from something, like solar cells or an electric power plant fueled by coal, natural gas or nuclear energy, to make hydrogen. Hydrogen can be made on an industrial scale from natural gas and even coal. It costs more energy to split the water molecule into hydrogen and oxygen than the energy you get from using the hydrogen in a fuel cell. No matter how efficient your process, you cannot go beyond the laws of physics.
Using hydrogen as an energy storage medium is almost the same thing as when you charge your Li-Ion, Ni-Cad, or NiMH batteries from your wall outlet. Using hydrogen is like using a battery. I say almost, because hydrogen is an extremely corrosive gas that requires careful storage in special containers. Fittings that can normally hold water and air under pressure may still leak hydrogen because it is the smallest element. Hydrogen storage is rocket science.
In order to produce sufficient quantities of hydrogen for use in a fuel cell vehicle from solar cells, you would need to invest tens of thousands of dollars in a solar array alone. Beyond that is the space that such an array would require (I'll let you do the math), electrolysis equipment, and professionally maintained containment systems. This is not a one-time investment. Fuel cells wear out just like regular rechargeable batteries do. Solar panels also have a useful life after which they must be replaced.
I have no love for the oil companies, by the way. I believe their days are numbered. There will always be some oil in the ground somewhere, but when it costs more energy to extract a barrel of oil than the energy gained from using that barrel of oil as a fuel, then the oil age as we have known it will cease to exist. This is known as Energy Returned on Energy Invested (ERoEI). Oil extraction back in the 1930s had an ERoEI of at least 30 to 1. Today, the ERoEI is much lower due to water injection, deep sea exploration, and refinery costs.
On our planet hydrogen doesn't exist freely outside of molecules. Some of those molecules contain stored potential energy. They are usually referred to as hydrocarbons, molecules containing hydrogen and carbon. They include natural gas, oil, and coal. These substances are extracted from the earth's surface, and the energy gained from them has been far higher than the energy used to extract them. This has been the basis of our industrial society. Hydrogen is found in abundance in water. The water molecule is an energy sink. To break it apart takes lots of energy. It is not a fuel. There is no such thing as a perpetual motion machine either.
I know that this post will come across negatively. I'm sorry for that. These are the facts. There are alternatives that do work, at least for the time being. Electric cars that run on batteries are available now. People have converted older cars to run on common batteries with electric motors. Another alternative is biodiesel or even used vegetable oil. Again, people have made conversions to existing diesel engines to run these alternative fuels. Transportation doesn't have to be rocket science.
Dave
