How to Make Water Fuel Cell

Due to losses, you actually get less energy from burning the oxygen-hydrogen mixture than it takes to electrolyze the water.

They gloss over that fact that external energy is needed.

Agreed. Why take energy, change it to another form and then use it immediately with all the inneficiencies of those changes. In the meantime using a transfer medium which is a fuel-oxygen mix just waiting for combustion. The concept of taking wind or solar or coal powered electricity to recharge the batteries to use in this process is ridiculous. Why not just use the battery power?

I'm glad they don't even think of storing the hydrogen-oxygen mix. See Spot transport oxygen on the Hindenberg. See Spot run. See Spot not run fast enough. See Spot splat.

You need a "unique" signal emitter to electrolyse water?

Dumb for dummies.

We have always used more energy to create energy
The advantage of this is its convenience and the ability of windpower or solar to create hydrogen gas.
While I question the effiency they may claim it's ability to use solar or wind to create a fuel is valuable.