How much do you understanding about Hydrogen?

Characteristics of Hydrogen and comparsion 

Hydrogen is a new energy source that is relatively unfamiliar to consumers, but hydrogen energy has been used in some industries for a long time. The main reason for using hydrogen as a fuel is safety.

   
The common point of the three hydrogen accidents in 2019 is that they occurred in the hydrogen fuel supply system.
It is judged that the leakage of the system and the high-pressure device caused the spontaneous combustion of hydrogen, and the release of a large amount of oxygen in the process of hydrogen production by electrolysis of water, resulting in high oxygen density and easy combustion, and related to human operation. These problems can be easily solved technically and administratively, and similar incidents will not happen again after that.
*Explosion at hydrogen refueling station in Norway injures two drivers; (at hydrogen refueling station)
*An explosion occurred in a hydrogen storage tank at a hydrogen plant in Gangneung, South Korea, resulting in 2
  deaths and 6 minor injuries；(in hydrogen production)
*Several hydrogen transport vehicles in Santa Clara, USA, leaked high-pressure hydrogen gas, causing
  spontaneous combustion and a series of explosions；(in storage and transportation)