Laws of Thermodynamics: Energy cannot be created or destroyed; You cannot get more energy out of a system than you put into it...
...and hot water requires ENERGY to heat it.
Where will the HEAT ENERGY come from?
It will come from a heating-fuel, and the heating-fuel
will not be hydrogen.
And there you have it! A vicious circle!
No magic-bullet solutions for the energy crisis!
There - is - no - free - lunch when it comes to energy.
What's available is what you get; nothing more, nothing less!
Boy! Did I get worked up about this topic.
Jacob