Hydrogen Refueling Stations

Unlike gasoline, hydrogen is a non-toxic, environmentally benign gas that can safely be stored under high pressure. A simple HRS consists of hydrogen storage tanks, hydrogen gas compressors, and a dispenser that dispenses hydrogen to vehicles at 350 bar or 700 bar (depending on vehicle type). Refuelling takes three minutes for a Mirai car and seven minutes for buses.

Which compressor lasts the longest?

Hydrogen can be delivered to a HRS in either gaseous or liquid form. When a station is supplied with hydrogen in gaseous bulk, a tanker truck pumps the fuel into aboveground tanks that store hydrogen refueling stations at a cryogenic temperature. When the tanks are empty, they’re refilled from a trailer or skid-mounted cylinder bank at lower pressures. Liquid delivery can increase the amount of hydrogen a single delivery truck can carry, but it requires more on-site bulk storage capacity.

When a vehicle arrives at the refuelling station, it connects to the nozzle through a closed system. The fueling process is supervised by a safety attendant and starts with initial integrity checks. The dispenser pauses periodically to conduct additional tests, according to code and fuel protocol, before the vehicle’s tanks are filled.

Depending on the station location, hydrogen can be produced on-site using a steam methane reforming (SMR) or electrolyzer unit. This method has the benefit of reducing a station’s energy costs but increases its capital expense (CAPEX). Currently, most hydrogen stations use off-site hydrogen supply for cost efficiency reasons. Some designs are being developed to incorporate on-site production for a hybrid approach.