The BIGGEST problem with clean energy

What about all of the issues with separating Hydrogen from other components like water or hydrogen peroxide. The systems to separate water are going to use reverse osmosis water which is power-hungry and how to handle the wastewater. The energy to separate hydrogen is enormous. Then storing it is complicated too because how do you hold a molecule that is smaller than all other molecules? And 1 last thing will Hydrogen rise into space like helium does?