Hydrogen probably is the answer, but its the containment system that is the issue. In theory, each "gas station" could literally be its own refinery since the only thing you need to produce hydrogen is water. Just keep passing water through a system and keep collecting the hydrogen to pump into cars.
Containing it securely and efficiently in a car is a bigger problem, believe it or not. Hydrogen isn't something you just readily compress without keeping it cool. When it heats up, it wants to expand quickly. In order to keep it cool enough that it stays nice and compressed and efficiently stored in a containter, you need a lot of insulation and technology. Otherwise, you get a car that has to refuel every 50 miles simply becuase you can't store enough of it onboard. Also, if you car catches on fire, do you want another Hindenburg right there?
Just like batteries, unless they can figure out to make the storage into something plastic or other lightweight based material, you quickly get a skewed savings over using gasoline.
Until a new battery technology can be done safely and efficiently, the current hybrids are probably about as good as its going to get. The next thing to do is put CVTs (continuous variable transmissions) and/or diesels into everything. The CVTs are just starting to come into their own and you will start seeing them in a lot of cars and trucks real soon. The evolution into 6 and 7 speed automatics just is way too many moving parts and although more fuel efficient, not very cost efficent.
I feel like I'm on Ellen's Adventure into Energy discussing all of this. Where's Bill Nye when you need him? :shrug:
Hydrogen is not the answer in the current state of things. 2 Major Problems for Hydrogen Economy:
1. Containment: You kind of touched on this, skirted arounded it anyway... Not only is H2 unsafe in compressed conditions, but what's a larger problem is the size of the molecule. The Hydrodgen atom is the smallest, and H2 is definitely the small molecule... Why is this a problem. Well, imagine that you have marbles (representing H2) and a basket with holes in it to hold the marbles. I've already said that the marbles (again, H2) are the smallest thing we are dealing with, so as you may guess, the basket has leaks. Shrink this analogy down to size, and that's what happens on a molecular level - the hydrogen gas cannot be fully contained. Sure, not all of the gas escapes, but hey! we are paying for that H2, which brings me to my next point.
2. Manufacturing: This is the main reason for this post. You didn't cover this one so well in the above statements. Hydrogen is the most abundant element in the universe, but unfortunately it rarely exists without being bonded with other elements. What does this mean? We have to produce it either from Methane or Water. Okay, you say. Get some water, hook up the batteries, make some H2. Well, hydrolosis is expensive as is the methane procedure. Neither of the two is a clean method unless a green energy source is used to make electricity (fat chance!). (All of this taken into consideration, the electricity used to make the H2 could just be used to power a car, taking out Hydrogen as a middle man.) So, the moral of this crazy process is that Hydrogen IS NOT and energy SOURCE. It is, however, an energy STORAGE device. Since we can't mine H2, we can't use it as a traditional fuel. The production of H2 is more akin to making batteries that store energy, or even compressing a spring. We don't mine batteries or springs, but we prepare them with other energy sources so that they hold energy we can use later.
All this said, the fuel-cell concept is very efficient and would be excellent if it used an abundant source... unfortunately, this latter requirement has not been fufilled as of yet. I hope this clears things up.
And the variable transmissions are very cool! If anyone wants further info, I suggest search How It Works. Currently, the Nissan Murano has a CVT (or atleast it did a couple years ago).
