Different types of hydrogen recharging stations

Hydrogen recharging stations can be divided into off-site stations and on-site stations depending on how they supply hydrogen to vehicles (whether they produce their own hydrogen or not). Hydrogen recharging stations that have been built across Korea at the moment are mostly
off-site (tube trailer-type) stations. Moving forward, however, stations for large capacity hydrogen buses are expected to be on-site stations.

Different types of hydrogen recharging stations(Sort, Method)

Sort	Method
Off-site hydrogen recharging station (Hydrogen supplied from an external source)	Hydrogen supplied from an external source Hydrogen produced from a plant is supplied via pipelines, tube trailers, etc.
On-site hydrogen recharging station (Hydrogen produced directly at the station)	Hydrogen produced by extracting (reforming) natural gas, electrolysis, etc. at the recharging station

Configuration of hydrogen recharging stations and recharging protocols

Similar to a CNG recharging station, an off-site hydrogen recharging station that receives hydrogen using tube trailers features compressors, storage containers, refrigerators/chillers, and recharging modules. One thing that is different from CNG recharging stations, however, is the cooling equipment which is used to prevent the temperature of hydrogen rising too high.

Maximum number of vehicles a hydrogen recharging station can recharge per day

At the moment, hydrogen recharging stations built by Hyundai Motor Group can recharge up to 70 NEXO vehicles per day (14-hour business day). (Recharge 5kg/vehicle) However, hydrogen recharging stations without high-pressure (900bar) storage tanks may require some additional downtime to repressurize the hydrogen in its recharging system using the compressors if they service too many vehicles in a day.

Hydrogen recharging stations moving forward will feature more robust equipment (minimum 1,200kg/day for a 24-hour business day) to make sure they can serve a greater number of FCEV.

• Specifications for a hydrogen recharging station built by Hyundai Motor Group: 25kg/hr (recharges 250kg/day on a 10-hour business day, 600kg/day on a 24-hour business day)
• Storage capacity of NEXO for hydrogen: 6.33kg (typically, 4~5kg of hydrogen is replenished at a time)

Recharging time for hydrogen-powered buses

Hydrogen-powered buses take approximately 30 minutes per vehicle to recharge based on the current capacity of hydrogen recharging stations. The reason why buses take longer to recharge is because hydrogen recharging stations at the moment are configured for passenger vehicles (considering the time it takes to re-pressurize the recharging system at the station, it takes 50 minutes to recharge one bus).

When the technology for hydrogen-powered buses become more mature, and when hydrogen-powered buses become more popular in the transportation system, hydrogen recharging protocols for commercial vehicles (3.6~7.2kg/min) will follow suit and reduce recharging time to within 15 minutes per vehicle.

• Specifications for the hydrogen recharging station at Yangjae: 14 NEXO vehicles/day (5.4kg/vehicle, recharged at 700bar), recharging speed of approximately 1kg/min
• Two hydrogen-powered buses were introduced into the mass transit systems in Seoul and Ulsan as part of a proof-of-concept testing initiative.
• The hydrogen-powered bus in Seoul uses the hydrogen recharging station in Yangjae. The station in Yangjae is for passenger vehicles, and as such, it takes approximately 30 minutes to recharge the hydrogen-powered bus.
• Storage capacity of a hydrogen-powered bus (engineered by Hyundai Motor Group) for hydrogen: 33kg (pressure at 700bar)

The stability and reliability of hydrogen recharging stations

Hydrogen recharging stations use components certified by competent authorities in Korea and abroad in all of their essential equipment. Depending on the relevant regulatory requirements in each country, hydrogen recharging stations feature hydrogen gas detectors, flame (fire) detectors, temperature/pressure sensors, and interlock safety devices to make sure the entire facility is safe against potential hazards.

Under the High-pressure Gas Safety Control Act, building a hydrogen recharging station in Korea requires safety inspections from the Korea Gas Safety Corporation and approval from the competent administrative authority. Meanwhile, safety management standards are similar to those enforced in Japan.

Today, there are roughly 370 hydrogen recharging stations around the world. In particular, France has a recharging station near the Eiffel Tower, and Japan has stations near Tokyo Tower and other densely populated areas. This goes to show that hydrogen recharging stations are perceived globally as safe facilities to have around people.

Roadmap for hydrogen recharging and supply by country

Both Japan and China also have plans to transition into hydrogen-friendly societies. In 2014, Japan announced its “Strategic Roadmap for Hydrogen and Fuel Cells in Japan (~2040)” and its government is planning to prepare the infrastructure necessary to usher in a hydrogen-friendly society by the Tokyo Summer Olympics in 2020. Meanwhile, the Chinese government has designated the FCEV industry as a future industry.
According to its supply plans, the government will distribute 5,000 vehicles by 2020, 50,000 units by 2025, and 1,000,000 units by 2030.
The Chinese government also announced that it would build 100 hydrogen recharging stations by 2020, 300 stations by 225, and 1,000 stations
by 2030.

How many FCEV and hydrogen recharging stations do we have in Korea? As of 2018, approximately 18,000 FCEV were produced in Korea
(domestic demand: 9,000 vehicles), which means that more hydrogen recharging stations are required across the country. In response to the rising demand for FCEV, the Korean government has established plans to increase the number of hydrogen recharging stations to 310 by 2022. According to the Ministry of Environment, there are 14 stations at the moment with 10 more coming by the end of the year.