A hydrogen refueling station must be supplied with gas to be able to operate.
If it is supplied with hydrogen gas produced on site by an electrolyser, it can be considered to operate "autonomously". The gas is produced on site, before entering the station to be compressed, stored, cooled, and dispensed to vehicles.
Another advantage of HRS stations is that they can be adapted to all types of hydrogen source. The gas can therefore be produced on site by electrolysis or transported to the site by truck, tube-trailer, or pipeline.