It is always amusing that some EV supporters accuse ICE-defenders as being close minded, then some turn around and have similar knee-jerk negative reaction to hydrogen, call them "fool cells", not keep up with the tech, etc.. LOL Sure, Toyota is spending $4B for PR benefits...sure, that makes sense. LOL. Double LOL.
I agree that emotional reactions and fanboy attitudes have no place in a policy discussion. But you cannot ignore the laws of physics.
1. Free hydrogen does not exist in nature. You have to make it with some type of process. The laws of thermodynamics dictate that there is no process by which you can take energy of amount A, use that energy to make hydrogen, then use the hydrogen to recover energy A without any losses. Thus, it is never more efficient to use hydrogen instead of using the original energy source that you started with.
2. With this in mind, you'll see that hydrogen is not an energy
source, but is functioning as an energy
storage mechanism, just like a battery or a fuel tank. Thus the argument becomes, how good of a storage device is it for energy? And the answer is, a very poor one.
Hydrogen is the smallest molecule there is, and as such it's very difficult to contain. You cannot transport it by pipeline because it will leak through every seam and joint in the pipe. To get it to an energy density that is practical, you need to store it as either highly compressed gas (10K psi) which requires large tanks with thick walls, or as liquified gas which requires cryogenic equipment. Transporting it means that all trucks that are carrying hydrogen must fall into one of these two categories, and either is far more expensive and more trouble than a gasoline truck.
Now, before anyone starts quoting specific energies (MJ/kg) or energy densities (MJ/L) of hydrogen, gasoline, or lithium-ion batteries, keep in mind that those values for the fuel itself are academic. Reality dictates that the true comparison has to be made along with the energy conversion device that will be in the car to convert the stored energy into work, and must take into account it's conversion efficiency. Thus, though gasoline is 32 MJ/L, once you have a large drivetrain and transmission, and an average conversion efficiency of 20%, the
usable MJ/L is quite low. Compare it to a lithium-ion battery (low energy density of only 2.5 MJ/L), but a 92% efficient small conversion device. Usable MJ/L is now on par with gasoline.
Hydrogen is in the same ballpark. You have a fuel tank with compressed H2 at 10kpsi, giving you 5.6 MJ/L, but you also have to have a large tank + fuel cell + electric motor + small battery for peak demand and regen capture, and an overall efficiency of 60% at best. Usable MJ/L is now down on par with the other solutions, and you would have been more efficient using the original energy before you used it to make hydrogen.
3. With any non-gasoline solution, you're looking at having to build new energy distribution infrastructure. With hydrogen, that is starting from scratch. With electrical, you already have a distribution system, you only need endpoints. Public endpoints are only going to be single-digit percentage of the chargers that need to be deployed, the majority will be at people's homes.
4. Any type of energy can be turned into electricity. Any future breakthrough in solar, wind, or other not-yet-conceived forms of energy can feed the electrical grid, letting a nation and a society have a maximally efficient marketplace for energy. The cheapest form of energy will prevail. Not so with hydrogen -- the only people that is good for would be the corporations who would control the production and distribution.
Sorry to burst Toyota's bubble, but hydrogen is an impractical solution no matter how you slice it. It doesn't matter if the Navy is creating hydrogen from seawater or not, the energy you're using for that would propel an electric car further under any circumstances. Hydrogen vehicle propulsion will never be practical and will never compete in the marketplace, and the reason is physics, not fanboism.
