Mail Online: Could you soon be filling up with SEAWATER? US Navy reveals 'game changing' fuel created from water
I could be misremembering, but the main photo (of the contraption) in the linked article looks to me like the same photo I'd seen in similar articles a number of years ago.
The problem is that it takes more energy as an input than the system/process outputs. This doesn't mean that such a process can't be useful in some circumstances. But, it does mean that such a process is *still* dependent upon some other energy source, such as fossil fuels, or nuclear, or possibly solar.
So, if the goal is to make portable fuel -- that is, to convert electricity into fuel -- such a process may be useful. But, if the goal is to generate electricity/energy, then it's counter-productive.