This technology has been around for years. Small welders for precision work often use this system. Google on "water welder" to see several manufacturers. Useful for small workpieces or where contamination must be avoided. More convenient and safer than tanks of compressed hydrogen and oxygen. As far as being a "revolutionary new power source", I have to loudly call "bullshit". The amount of electrical energy needed to convert the water into H2 and O2 will ALWAYS be more than the energy you get back by burning the gases produced. Unless you have a free source of electricity, you will pay more in electrical bills to run a car this way than you would buying gasoline. Even if you DID have a "free" electrical source (solar, etc.), you would get higher overall efficiency using it to charge batteries to run a traditional electric vehicle than you would by using the electricity to split water to get hydrogen.
Yea, no you will never get to the point where you get more energy than you put in to split water into gas then to convert it back.
