Anyone here ever heard about hydrogen cell train? Alstom launched the world's first hydrogen fuel cell train by the technology supplied by this developer and manufacturer of hydrogen generated fuel cell products called Hydrogenics. I really wonder about the production of hydrogen fuel? Will hydrogen technology be the fuel of the future? What do you think about it?

We kind of have a lot of it in water!  Most likely more efficient to have a central power plant (even a small on) that is powered by hydrogen and then just send the power the usual way to the catenary system.

Nope. Hydrogen isn't a fuel, it's an energy storage medium - and not a particularly good one. Hydrogen needs to be created - which takes energy. Molecular hydrogen does not exist naturally on Earth, it was lost to space almost immediately after the Earth was formed.  So you have to liberate hydrogen atoms from other molecules like methane or water, and once you create molecular hydrogen it needs to be compressed, cryogenically stored, and transported to where it's needed - all of which takes more energy. Then it needs to be put through a fuel cell (with significant inherent losses) to be made into electricity again to run the electric drive of the train.

All in all, from creation to consumption you get about 30% of the energy you put in to making the hydrogen back out.

It's basically a crappy battery with a propensity to explode if not handled correctly. And that's not an exaggeration, two hydrogen handling facilities exploded this year, one in California and one in Norway. California is still without hydrogen as we speak and it has been many many months. Norway has halted sales of hydrogen vehicles altogether as a result of their explosion.

It's much more efficient to use the electricity created by hydro dams, solar farms, wind arrays, nuclear facilities etc. and run that electricity through high voltage wires (at minimal loss) which already exist and then feed it directly into an overhead catenary system to be used by trains. There are fewer losses, no risk of explosions and the infrastructure already exists. Why move a physical, bulky, leaky and potentially explosive thing when you can just push electrons through some wires?

A similar argument works for cars as well which is why you've likely never seen a hydrogen car in real life but pass dozens of electric cars on your commute every day. The argument for hydrogen is tenuous at best. It may have a place in large ships, where it can be produced in a port facility and put directly into vessels that dock, but for daily use in cars and trains its foolish because better alternatives already exist thanks to batteries and OCS's.

Oh and fun trivia...do you know why it's called a 'fuel cell'?

When the Americans were trying to get a man to the moon they realized they needed some kind of onboard power supply and solar wasn't going to cut it (in the '60's). They couldn't use their standard nuclear batteries that they put on basically every deep space probe because there would be people onboard and radiation doesn't mix well with humans. The problem was they also had a severe weight restriction since getting to the moon is hella expensive and every gram counts so that meant dedicated batteries were also not really an option (lithium ion batteries wouldn't exist for another 30 years or so). Some bright boffins figured out a way to combine the rocket fuel they already had onboard (aka hydrogen) with the oxygen they already had onboard (which was the oxidizer for the rocket fuel) in such a way as to create an electrical current and get pure water as the byproduct, which was handy because people need to drink water to stay alive anyway. To the "fuel" in fuel cell is referring to rocket fuel. Cool eh?!

But wait! I said hydrogen isn't a fuel right?!...that is true as far as how most people understand a fuel. When people think of a fuel they see it as a source of energy. Gasoline requires a little bit of energy to percolate it out of a barrel of oil but the return on energy to do that is relatively low plus the oil in that barrel gushes out of the ground in some places by itself and is even usable without refinement if you wanted to so even gasoline is a net energy gain. Natural gas just comes out of the ground by itself too and is a great source of energy as well (environmental damage notwithstanding). Hydrogen isn't a source of energy like that, it's a net energy loss. It consumes energy just to get it to exist here on earth. NASA has to create hydrogen for its rockets to use it as a "fuel". It's expensive for them to make but when you're talking space things it's relatively cheap. It has decent energy density and is non-toxic compared to some of the other rocket fuels available. Plus it really likes to explode which is good if you are making a rocket (but not so much if you are into airships, cars, or trains). The cost is prohibitive for us non-space faring mortals plus you can't run an overhead catenary up to the ISS.

Thanks for your valuable infomations.