Vaporware: Water For Fuel
The secret to hydrogen fuel is not building an engine able to burn it on all kinds of different scales from lawn mowers and motor cycles to large trucks, trains and ships. The secret is how to get the hydrogen atom by itself from all of the other elements that like to use that handy little atom as part of their structure.
For example, water is a very plentiful element on this planet, but it takes a whole lot more energy to break the H2O molecule into the separate atoms than is produced by burning the resulting gas. But what would happen if we could simply open the molecule like a can of compressed air and use the resulting pressure release as a power source without burning anything?
The key to making the whole hydrogen thing work is a special frequency. In the most simple terms this is much like a microwave oven that uses a frequency near the wavelength of the water molecule to excite that molecule causing it to vibrate and generate heat. Unlike the common microwave oven, the frequency used to separate the molecule into atoms is much higher in the range that weakens the bonds holding the H2O (and similar) atoms together. This makes it much easier to break them into gas form with only a small fraction of the energy normally needed. The difference is so much less that one of these engines with ready access to almost anything containing water, like the ocean, can virtually run forever.
This means wells can pump their own water without any outside power source. Giant ships that used to burn tens or hundreds of thousands of Dollars worth of fossil fuel each hour now run effectively for free. Only the desert needs a fuel distribution network, but it is now possible to build pipelines pumping water thousands of miles to these areas completely self-powered.
Anyone with a hose long enough to reach any kind of water, including waste water, now can be in the fuel business. Distribution is no longer an issue because virtually every place on the planet has access to non-potable water.
It is now possible to build an engine that generates electricity directly from the separation process allowing the gasses to reform back into pure liquid-form H2O. The result is two very interesting byproducts. The first is that electricity is now virtually free. The second is that clean air and potable water pours out of these engines no matter what water is used for a fuel source.