Hydrogen has by far the best subsidies in the Inflation Reduction Act, though. Funneling money from taxpayers to corporate coffers via government subsidies has proven a winning strategy in many other industries.
Cynically, Hydrogen subsidies today are simple greenwashing of traditional Oil & Gas subsidies and still are benefit the same corporate coffers. Most hydrogen production is a side project of the oil & gas companies and a "by product" of refining operations.
I'm pretty cynical by nature, but I don't think that's what's at play here. The IRA's hydrogen production subsidies explicitly don't apply to hydrogen produced from fossil fuels; it has to be from zero-carbon production chains. Moreover, the IRA has upended the economics of the hydrogen market - with the subsidies, electrolyzed hydrogen is now cheaper than methane-derived hydrogen. [1]
There's also significant subsidies for hydrogen storage technologies, hydrogen vehicles, and hydrogen fueling stations.
Personally I'd take this at face value: the point is that hydrogen has the potential to decarbonize a lot of industrial & transportation uses of fossil fuels, and so it's attempting to build up the necessary technology and infrastructure to make this practical. There are always side effects when you throw massive amounts of money at a problem, so I'd expect some boondoggles, but at least the intent of the law isn't a boondoggle.
What advantages do hydrogen cars have over ICE or electric? I know very little about them. Electric, optimistically, is cost effective (especially if you have solar panels) and convenient. ICE at least has industry momentum going for it. But Hydrogen? Unsarcastically, why?
There are two reasons why Toyota is pursuing hydrogen.
First, the well known short comings of BEV as often pointed out on HN. The most common is range anxiety (dead electric car) and how long it takes to recharge (30 minutes at a quick charging). With a hydrogen fuel cell vehicle, it has a higher energy density so its range is farther and it takes about 10 minutes to fuel up a Toyota Mirai with hydrogen. This is the reason why commercial trucks and long distance trains are looking at hydrogen fuel cells. [1] [2] [3]
The second and probably more important reason why Toyota is betting on hydrogen is that the Japanese government mandated it. [4] By 2050, Japan wants to transition off fossil fuels using a combination of electrification and hydrogen/methanation/synthetic fuels/biomass. See slide 2(2) Energy Outlook of Carbon Neutrality in 2050 from [4]. This make sense to Japan. Japan is not only looking passenger vehicles. Japan is thinking about how to wean off commercial trucks, heavy industry, and shipping off fossil fuels. It thinks that hydrogen fuel cells may be the answer.
The biggest drawback with hydrogen is that transporting long distances requires cooling hydrogen to –253 °C [5]. However, in 2006, the US Department of Energy had already talked about using ammonia as the "hydrogen carrier" [6]. Ammonia can be transported at –33 °C [5]. The Department of Energy envisions transporting liquefied ammonia via pipelines, trucks, and tankers. Then "cracking" it back to hydrogen at a substation.
>Ammonia may be considered as a potential hydrogen carrier for hydrogen delivery and for off-board storage, such as at refueling stations and for stationary power applications. Ammonia, delivered to refueling stations and stored onsite, would need to be reformed prior to vehicle filling and levels of trace ammonia in the hydrogen stream would need to be reduced to meet fuel purity requirements (e.g., < 0.1 ppm NH3) for PEM fuel cells. The use of ammonia as a hydrogen carrier is being investigated further by DOE’s Hydrogen Delivery Program and the FreedomCAR & Fuel Partnership’s Hydrogen Delivery Technical Team.
Hydrogen fuel cells can't compete with battery EVs on energy efficiency, if the hydrogen is produced from electricity by electrolysis. (Most hydrogen is made from natural gas.)
Hydrogen beats batteries in terms of energy density, so maybe it has a future in aviation. I think ground transport will eventually all transition to battery electric (and hopefully we'll get electrified roads at some point so battery size and range isn't really an issue anymore) unless energy somehow becomes so cheap that we just don't care how inefficiently it's being used. I don't expect that to happen any time soon though.
I've seen some interesting data that suggests hydrogen fuel cells may not even have a future in aviation. Air travel does currently rely on some efficiencies from planes being lighter as they travel due to fuel spend, which is something that hydrogen fuel cells would share. But the theories I've read suggest that torque will be the huge overriding efficiency (and safety) benefit to electric aviation (that electric motors have access to nearly 100% torque at all speeds, if you have the available power draw). In that case, hydrogen fuel cells become a massive power draw bottleneck on torque, dropping motor efficiency, so you want a big parallel battery for moments of large power draw. At that point if you are already building around the weight of a large battery you might as well right size the battery for complete range and drop the inefficient of "dual power sources".
From what I've read that seems to already be playing out in small planes that fully battery electric is winning over hydrogen or hybrid hydrogen/battery. It will probably be another decade or so before we see how it plays out on the larger planes.
The only place I've heard hydrogen might win out is large sea transport (large cargo ships and cruise liners), and even then there are interesting recent developments in wind power for ship's cruising speeds and battery charging that are going to be competing with hydrogen
I agree it makes sense for ships to use hydrogen. You might have a point about power density of fuel cells being too low for aviation. I don't think batteries will work for aviation except for very short flights, unless there's a major technological improvement -- in the near term probably the best low-carbon option is some kind of synthetic liquid fuel.
Lots of things could work. The logistics of hydrogen make it laughable as a mass replacement for gasoline as an energy fuel for mass market.