Chevy Volt Follows Stupid 2012 with Stupider 2013

Because hydrogen does not occur by itself on Earth. It is always in a compound with something else; often oxygen (in water) or carbon (natural gas, etc.). To split it out of these compounds takes exactly as much energy as you get back when it recombines; so if you electrolyze water, you need to put in as much energy as you will get back out.

So, hydrogen can be used to store energy from something else; but it is not a source of energy itself.

However, solar power can create the energy to electrolyze water. And, there is a market of oxygen gas.

There are only two sources of Hydrogen. Cracking petroleum products. There is no benefit to this as you are still using petroleum though you might not create CO or NOx compounds. Or electrolyzing water. in which case you are wasting 1/3 of your energy creating Oxygen. Thereby making it very expensive. If solar panels can ever crack the 40% efficiency barrier, Hydrogen may become viable as an energy storage product.

Did you ever hear the word "Hindenburg"?

Look it up someday.

Hydrogen produces water and only water. Only water oxidizes or rusts things. It is bad enough that we have to have 10% ethanol in gasoline. That is why my pickup is sitting idle behind the barn. The ethanol has destroyed the seals in the carburetor. My chainsaws are being destroyed by ethanol too because of the breakdown of ethanol and it's absorption of water. Water, aka, burned hydrogen, is death to internal combustion engines, unless you have an all ceramic engine that easily cracks and accepts no impact.. In short, water destroys engines. Corn squeezins "ain't" for "burnin" nor "drankin" dude. In gasoline, it will destroy an engine. Drinking it will destroy your liver and may cause you to kill someone in that Volt.

Hydrogen is actually quite safe. It is so light that if it leaks, it dissipates far faster than, say, methane (natural gas), and certainly far faster than gasoline vapors. I can't imagine that it would be any more dangerous than using natural gas under pressure, and that is being done now.

The big problems with hydrogen are: (1) it must be stored under very high pressure, which leads to leaks, fueling problems, etc; and more importantly (2) it has too low of an energy density when measured by volume (not weight). A 10-gallon tank of hydrogen under pressure has a lot less BTU's than a 10-gallon tank of gasoline. So your range suffers immensely.

Also, there is the separate issue of not having infrastructure to distribute and sell it.

Hindenburg

Challenger

Hydrogen is cheap, but the fuel cells needed to contain it are expensive. Also, hydrogen is quite explosive. If they can solve these problems with future designs, then there's no reason we can't see hydrogen-fueled cars sometime in the future.

"...the fuel cells needed to contain it are expensive..."

Hydrogen, being the smallest element at the molecular level, cannot be completely contained. It "leaks". Even through solid steel.