Standard flow rate (60-120 g/s)

Normally, hydrogen refuelling stations (HRS) operate at 350 or 700 bar. Most of the stations for passenger cars are designed for operating at 700 bar, while stations for buses typically use 350 bar. For this reason, the majority of the stations currently operate at 700 bar, with many of them operating on a dual basis, being able to deliver fuel to both at 350 and 700 bar.
Hydrogen refuelling can be standalone, or linked to a hydrogen production station. If the hydrogen is delivered to the station in intermediary form, storage and compression systems are needed. Hydrogen storage systems are generally low pressure, around 50-200 bar. Compressors overcome the pressure difference between storage and refuelling (which can be up to 1 000 bar), and they are a central area of innovation in hydrogen refuelling stations. Most of the time, storage buffers (at 450 or 950 bar) are used to refuel vehicles (without a direct connection of vehicles to compressor outlet).
A range of technologies can be employed for compressing H2 from low pressure states to up to those needed at the point of use, depending on whether hydrogen is in gaseous or liquid form, and on the throughput vehicle type. High levels of purity are needed in fuel cell applications, so technologies like ionic compressors are needed to reduce the possibility of contamination.
During compression the hydrogen gas heats up, and precooling systems are needed to stay within the limits of the vehicle’s fuel storage system. These systems add complexity and increase energy consumption, and are a key area of development for improving the efficiency and reducing costs of hydrogen refuelling systems.