Or is it a pipe dream*?...
* Just one contrary view among many: This is just another version of the "free energy" engine. You cannot, as proven through solid laws of physics (2nd Law of Thermodynamics), get more energy out of a system than was put in. Water is not fuel, and has to be converted into hydrogen and oxygen to make fuel. The energy required to convert cannot be less than the value of the energy obtained once converted. The extra energy has to come from somewhere. Fossil fuels are already storing energy ready to be used, since nature provided the energy to convert them into their current form over eons. That is why there are no water engines. It is NOT because of some conspiracy. Junk science might get lots of views on social media, but that does not elevate its value.