You
can convert seawater to fuel. Fantastic, but what is it going to cost? Not in terms of dollars, but in terms of energy. How much oil do you need to burn to burn in order to convert each gallon of seawater into the corresponding fuel amounts, and how much would you get out of it?
People would have to be idiots to use power generated by fossil fuels to produce this stuff. Luckily we have a pretty simple solution and one which is actually quite safe and a lot less damaging to our environment than coal or oil: nuclear energy. Modern reactor designs have basically eliminated the risk of melt downs and produce almost no waste. In fact, the waste they do produce can readily be stored on site, and quite safely with almost no risk. Too bad there are a lot of ignorant people out there who hear nuclear and think Chernobyl or Fukushima and don't have the first clue that those plants are about as indicative of what modern nuclear power is as a sailing ship is indicative of what the modern day US Navy is capable of.
Then, once you have gotten enough, does the power it supplies produce enough to enable you to extract and convert a greater quantity of water to fuel?
Again, with hydroelectric, nuclear, geothermal, etc. it doesn't have to produce enough power to convert more water into fuel. This is a fuel source which could potentially be used to continue fueling every day vehicles while we use the centuries worth of nuclear material we have to create it and power our homes. If this stuff is as effective as the story claims, it really is that simple.