Wow, break through in hydrogen greation from MIT

[Snowreap]

the oxygen and hydrogen have to come from somewhere, they don't materialize from sunlight. typically you use water as your source of hydrogen and oxygen atoms, although it's heavy to carry around for this purpose. you might as well just carry the oxygen and hydrogen separately to start with and be done with it.

plus, you can't burn hydrogen without an oxidizer (like oxygen). so if you want to use it as fuel you might take energy from the sun, split water into hydrogen and oxygen, then mix them back together to produce steam (steam is what you produce when you 'burn' hydrogen), which you eject out the nozzle of your engine. this is a lot of effort for no net gain (you could have used the sunlight to produce steam directly). plus, when you run out of water you run out of oxygen and hydrogen atoms, so really the water is your fuel in this case.

this isn't a way to produce energy, it's just an efficient way to store energy you already have access to.

-ken