Hydrogen vehicles will never become popular. There are several reasons for this:
- To be carbon-neutral, the hydrogen must come from splitting water.[1] Currently hydrogen comes from steam reforming of methane (which releases lots of carbon).[2]
- Hydrogen is a very pernicious molecule. It will slowly leak through metal and weaken it.[3]
- Hydrogen vehicles must be refueled at special fueling stations. Electric vehicles can be charged anywhere there is electricity (such as at home).
- Hydrogen fuel cell vehicles are more expensive than battery electric vehicles. Toyota sells the Mirai for $57,500 and loses money on each one.
- Storage and transportation of hydrogen is very difficult. It must either be stored in gaseous form at very high pressure, or in liquid form at 20 degrees above absolute zero. Current vehicles use high pressure tanks, which also require high pressure pumps. Many hydrogen stations can only provide 5,000psi pumps, which means you'll only get half a tank (and half of your expected range).[4]
- Hydrogen is more flammable than gasoline (it will ignite in a much wider range of mixtures with oxygen).[5] Unlike gasoline, the flame is invisible in daytime. Unlike gasoline, hydrogen is invisible and has no smell, making leaks undetectable without special equipment. If an odorant is added to the hydrogen, it will likely damage the fuel cell.
- Hydrogen is more expensive than gasoline and far more expensive than electricity. Even with subsidies, refilling a Toyota Mirai costs over $80.[4] That gives you just over 300 miles of range. My Tesla Model 3 has the same range and a full charge costs me $6 at home. Supercharging is also cheaper, at around $25.
- Batteries got cheap faster than anyone predicted (except Tesla). In 2015, a study looked at past estimates of battery prices versus observed prices. They found that analysts were consistently pessimistic about cost reductions. Correcting for this, they noted that cost per kWh, "...could reach $200 by 2020." Actual cost in 2020 was $123.[6]
Given all of these disadvantages, I don't see how hydrogen vehicles could be considered reasonable. The economics, physics, safety, and convenience simply don't work out.
1. https://en.wikipedia.org/wiki/Water_splitting
2. https://en.wikipedia.org/wiki/Steam_reforming
3. https://en.wikipedia.org/wiki/Hydrogen_embrittlement
4. https://www.cars.com/articles/fill-er-up-refueling-the-2016-...
5. https://en.wikipedia.org/wiki/Hydrogen_safety
6. https://www.weforum.org/agenda/2015/04/will-falling-battery-...