Highlight of the RHEC-2021 is the overall recent progress of hydrogen technology including hydrogen production, storage, infrastructure and its utilization. This comes followed by discussion on national hydrogen energy strategies, codes, public acceptance, national legislations, regulations, and directives for its introduction on global level. Within RHEC-2021 we are also focusing on the fields that currently don’t have much connection to the hydrogen, but what will come sooner than later. And this is where, among others, ICT sector is expecting to play noticeable role. ICT is the great electrical energy consumer, and its energy demand is expecting to continue to grow. In order to reduce CO₂ emission, and to keep global warming below 2^o C, we need to focus on clean energy, i.e. RES in all sectors. Due to their intermittency, RES comes in conjunction with energy carrier and energy storage, and this is where hydrogen takes its major role as an efficient, and CO₂ free energy carrier that could enable, among others, ICT to make positive change with its carbon footprint.