I have been dreaming if there is a way to generate power from water. This dream power generator will just convert water to electrical power with Oxigen as its residue.
This technology shall be cheap to make and compact enough to fit into a car. I imagine till will reverse global warming effect. Why? because, first, it takes water from sea to generate energy. Secondly, it does not generate much pollutant to the ozone layer. Third, it generates oxigen essensial to human.
That's just (all will stay) as my imaginary dream, eventhough with fusion we could similarly do create energy from oxigen, but the technology is still far from practical use.