Actually, it's pretty inefficient as a storage solution. There are far better storage systems that loose far less energy. Efficiency is important if the input

Actually, it's pretty inefficient as a storage solution. There are far better storage systems that loose far less energy. Efficiency is important if the input (energy) is not free. That's why hydrogen based transport is a non starter because it costs about 3-5x the amount of energy. The other problem with hydrogen is that both storing and transporting it are hard problems. A lot of it just boils off. It takes up a lot of space. Compressing it to 600bar takes up a lot of energy and requires some heavy duty equipment. Etc. Most hydrogen that is currently produced is used on site and not stored/transported.