Storage and transportability. Even if end to end efficiency is between 10-20% for green hydrogen (solar/wind electricity generation -> electrolysis -> hydroge

Storage and transportability. Even if end to end efficiency is between 10-20% for green hydrogen (solar/wind electricity generation -> electrolysis -> hydrogen/ammonia -> fuel cell -> electricity), it helps solve the problem around intermittency for renewables. To power a large electricity network with just wind/solar, it will need to be over-provisioned to the point where peak production will be heavily curtailed and lost or redirected to storage. Electricity needs to be used at the time of supply for something otherwise generation is wasted. Batteries are great if you need to redirect that power over the course of an hour or maybe a day and are highly efficient but too costly at any kind of large scale. Most solar/wind at present day are only built with battery support of about 1-2 hours worth of equivalent storage. This is a massive help to smooth output but doesn’t help any kind of long term storage. Then there is transport. Poles and wires are expensive to build/maintain. Their highly efficient but completely inflexible. Hydrogen can be stored at large scales as well as be transported, plus be generated from generation that would otherwise be curtailed and lost due to having nothing to use it on. Pumped hydro needs specific geography and is also hugely damaging to river eco systems, not to mention ties up a huge amount of a valuable resource (water). Renewables also geographically dependent, some places on earth are bestowed with huge amounts of wind/solar where others are not. Some of this will be solved by building international power lines, but smaller scale will likely want something like hydrogen fuel. I’m very cynical of old/current energy companies and they are doing everything they can to slow this transition but hydrogen will very likely be part of the mix into the future. What I’m not sure of is if it will serve a massive part like heating Europe over winter via excess generated over summer or much smaller for backup of more remote decentralised grids I don’t know but it will definitely play a part in the energy mix for generations to come.