Frequently Asked Questions

What is green hydrogen? What is the process for producing hydrogen? What are the advantages of hydrogen for mobility? 

This section contains our answers to your questions.


How is hydrogen produced?

There are several ways of producing hydrogen:

  • Currently, the most common method is steam methane reforming, in which methane molecules (CH4) are broken down by the addition of water vapour (H2O), from which hydrogen is obtained. In 2021, this method accounted for approximately 50% of global production.
  • Coal gasification is another method, in which the molecules are broken down by heat in the presence of water and partial oxidation of petroleum. This method accounts for less than 50% of global production.
  • Because the above methods release CO2, processes are used to capture these molecules so that they can be stored or reused instead of being released into the atmosphere. This is known as blue hydrogen.
  • Water electrolysis produces H2 by breaking down the water molecule (H2O) using an electric current. It accounts for 4% of hydrogen production. If electricity is produced using renewable energy sources, this method can be used to manufacture green hydrogen.

Source : IRENA (International Renewable Energy Agency)

How is hydrogen stored?

Storing hydrogen makes more sense when it is produced using renewable energy sources (e.g. solar and wind), the availability of which varies over time, and which are not easy to store by other means.

There are several ways of storing hydrogen:

  • Hydrogen storage as high-pressure gas, in which it is stored in pressure-resistant cylindrical tanks. This type of tank is used in HRS hydrogen stations and in vehicles.
  • Hydrogen storage by cooling to a very low temperature below -253°C to convert it to a liquid. In its liquid state, the hydrogen is stored in vacuum-insulated tanks.
  • Solid hydrogen storage: some porous materials such as activated carbon and metal hydrates can absorb hydrogen into their surface. This enables hydrogen to be stored in a reversible way and at lower pressure. Absorption hydrogen storage is a developing technology that shows promising potential.
Is hydrogen a green energy source?

Hydrogen is often considered a form of green energy, mainly due to its clean energy use. When used in a fuel cell, hydrogen reacts with oxygen in the air to produce electricity and emits water vapour. This reaction does not generate greenhouse gas emissions or atmospheric pollutants.

Hydrogen can be considered a green energy source when it is produced using renewable energy sources such as solar, wind or hydroelectricity. It is considered green because it does not contribute directly to greenhouse gas emissions. It is therefore known as "green hydrogen".

Why is hydrogen the energy of the future?

Hydrogen offers a means of decarbonising certain sectors that may prove difficult to electrify, such as heavy goods transport (trucks, trains, ships). By using hydrogen produced using renewable energy sources, these sectors can reduce their greenhouse gas emissions and help to combat climate change.

Unlike some energy carriers, hydrogen can be stored. It can therefore be produced when there is an abundance of renewable energy sources (such as solar and wind), then stored for use when the energy demand is higher or when the renewable energy source is less readily available.

Hydrogen can be used in a variety of applications, from hydrogen fuel cells for producing electricity to industrial applications, heating, and mobility. Its versatility makes it an attractive solution for various sectors, making it popular as a future energy source.

Lastly, by using hydrogen produced from renewable energy sources, it is possible to reduce reliance on fossil fuels. This offers advantages in terms of energy security, diversification of energy sources, and the reduction of atmospheric pollution linked to the use of hydrocarbons. In fact, hydrogen can be produced directly where it is needed by installing an electrolyser.

What is hydrogen?

Hydrogen is the simplest, lightest, and most abundant atom on the planet.
The term hydrogen is commonly used to refer to the dihydrogen (H2) molecule which is composed of 2 atoms of hydrogen.

It is usually combined with other atoms, for example in water (H2O), or in hydrocarbons such as methane (CH4).

It can be used in industry (to capture sulphur and carbon) to produce ammonia and manufacture fertiliser, as well as in the mobility sector as an energy carrier for vehicles.

What is green hydrogen?

Green hydrogen is produced via water electrolysis, in which an electrical current from a renewable source is passed through the water. The energy used comes from solar, wind or hydroelectricity. This type of hydrogen is known as "green" because it is decarbonised, and no CO2 is emitted during its production.

What is the future of green H2?

Numerous low-carbon hydrogen production projects are currently in development to quickly boost its role in the energy mix in the short term. The IEA estimates that all projects currently under way could lead to annual production volumes of 0.6 Mt of hydrogen in 2021, rising to 24 Mt by 2030.

In France, France Hydrogène estimates that decarbonised hydrogen will increase from 5% of the mix in 2022 to 52% by 2030, or 700,000 T of decarbonised H2 for industry and new applications, resulting in a 6,000,000 T cut in annual CO2 emissions and the creation of more than 100,000 jobs1.

The French government has stated its aim to "make France the leader in decarbonised hydrogen". Under the France 2030 plan, France is set to invest 9 billion euros in the development of this low-carbon hydrogen. The plan involves the creation of a competitive sector, R&D labs, industrial entities, and an objective to become the leader in electrolysis.

To find out more about plans to contribute to hydrogen mobility

1 France Hydrogène

What are the different colours of hydrogen?

There are several different colours of hydrogen:

  • Green hydrogen is produced by water electrolysis, which involves passing an electric current from a renewable source through the water. To find out more
  • Grey hydrogen is produced by steam methane reforming: methane (CH4) reacts when water vapour (H2O) is added to it, releasing hydrogen and CO2.
  • If the CO2 is captured at this stage for storage or use, the hydrogen is known as blue hydrogen.
  • Pink hydrogen, or yellow hydrogen, is produced by water electrolysis using nuclear energy.
  • White hydrogen, or natural hydrogen, refers to hydrogen that occurs naturally below ground.

Because no CO2 is emitted during its production, green, blue, or yellow hydrogen is also referred to as "decarbonised hydrogen" or "low-carbon hydrogen".

What is hydrogen used for?

Hydrogen is an energy carrier, and can be used to:

  • Store electricity, in particular that produced using renewable energy sources
  • Produce fertiliser from ammonia
  • Refine hydrocarbons
  • Fuel low-carbon mobility solutions

In fact, 1 kg of hydrogen releases three times more energy than 1 kg of petrol.

In mobility applications, hydrogen is suitable for:

In use, it does not emit greenhouse gases or pollutants, only water vapour.

Hydrogen mobility

How does hydrogen fuel work?

A hydrogen powered vehicle is usually equipped with a fuel cell.
The fuel cell vehicle is an electric vehicle that produces its own electricity on board.
Once the vehicle has been filled with H2 at the refueling point, the hydrogen is stored in the vehicle before it enters the fuel cell. Inside the cell, the H2 reacts with the oxygen (O2 ) in the air to produce water (H20). This reaction generates electricity which powers the engine, as well as steam which is discharged via the vehicle's exhaust.
A vehicle powered by green hydrogen does not emit CO2 or greenhouse gas.
Vehicle manufacturers are also working on hydrogen internal combustion engines.

What are the advantages of the hydrogen fuel cell?

Hydrogen fuel cells are known for their energy efficiency. They can convert hydrogen molecules directly to electricity.

One of the main advantages is the production of electricity without harmful emissions. When hydrogen reacts with oxygen in the air inside the cell, it only releases water. It is therefore a clean technology that does not contribute to greenhouse gas emissions.
Moreover, fuel cells can be used to power quiet, vibration-free vehicles.

Finally, cells perform well in extremely cold conditions, at high altitudes and in thin air, as illustrated by the endurance record set by a Hyundai Nexo during a 6-hour drive at an altitude of 2200 m in December 2021. "Hydrogen" versions of snowplough and snow groomers are also being developed to reduce the carbon footprint of winter sports resorts.

Why use hydrogen for mobility?

Hydrogen is a powerful energy carrier with a high energy density: 1 kg of hydrogen is equivalent to 3 kg of petrol.

H2 is better known in its gaseous state for mobility applications. Thanks to its lightness and low density, it can be compressed for use, usually to 700 bar for light vehicles and 350 bar for heavy mobility applications.

Liquid hydrogen also offers advantages for mobility since, in this state, 1 kg of hydrogen is equivalent to 4 kg of petrol. Liquefying H2, on the other hand, requires it to be cooled and stored below its condensation point, at -253°C.

What is the difference between a fuel cell and a hydrogen internal combustion engine?

The main difference between a fuel cell and a hydrogen combustion engine is found in the process by which the hydrogen is used.

A fuel cell converts hydrogen and oxygen into electricity and water. This electricity can then be used to supply an electric motor which powers the vehicle.

The internal combustion engine principle involves mixing hydrogen with air in a combustion chamber and igniting it to create a controlled explosion. The explosion generates mechanical energy which is converted into motion, thereby propelling the vehicle.

The architecture of a hydrogen combustion engine is similar to that of a conventional combustion engine.

What is the difference between an electric vehicle and a hydrogen vehicle?

A hydrogen vehicle is an electric vehicle.
Battery electric vehicles (BEV) are powered by charging points connected to the electricity grid;
Fuel cell electric vehicles (FCEV) convert H2 into electricity on board.

The main difference between an electric vehicle and a hydrogen vehicle is in the way in which they store and use energy. Electric vehicles use batteries to store the electricity, while hydrogen vehicles use fuel cells to produce the electricity, and tanks to store it. Electric vehicles require longer recharging times, while the refueling time for hydrogen vehicles is similar to that of petrol vehicles.

The technologies are complementary.
Using hydrogen for mobility can boost the range (500 to 700 km) and reduce the recharging time (by around 5 minutes for a light vehicle). FCEVs are therefore perfectly suited to intensive and continuous use. BEVs may be used as light vehicles to make short journeys, and may be recharged if there are no limits on time.

Hybrid hydrogen/electric vehicles are available on the market: equipped with both a battery and a fuel cell, they benefit from a recharging system that uses an electric power source with the added advantages of hydrogen.

To find out more about the advantages of H2 for mobility, click here.

What are the advantages of the hydrogen solution for transport?

The use of hydrogen as a fuel in vehicles helps to reduce greenhouse gas emissions and atmospheric pollutants. When used in a fuel cell, hydrogen generates electricity and discharges only water. This means it helps to improve air quality and combat climate change.

Hydrogen can be used for all vehicles (cars, buses, trucks, trains, planes, machinery, boats, etc.).

Hydrogen vehicles offer a similar range to that of combustion engine vehicles. Moreover, hydrogen refueling can also be as fast as petrol refueling, requiring just a few minutes to fill a tank. These two points distinguish hydrogen vehicles from battery electric vehicles.

Finally, using decarbonised hydrogen also helps to reduce reliance on fossil fuels, contributing to energy security and the diversification of energy sources.

Hydrogen stations

How long does it take to refuel a hydrogen vehicle?

Hydrogen refueling at our HRS stations is done in accordance with the SAE J2601 standard which sets out a protocol that takes into account the pressure, flow rate and temperature.

The filling speed is approximately 1 kg/minute, or around 5 minutes for a passenger vehicle. Faster refueling is possible for heavy-duty vehicles: around 15 minutes for a bus (30 kg).

Because fast refueling is one of the main advantages of hydrogen for mobility, HRS is working to develop very high-speed refueling. Through our involvement with the RHeaDHy project, we are aiming for a fivefold reduction in the refueling time for heavy-duty vehicles.

The objective: refueling of a high-capacity truck (100 kg) in just 10 minutes!

How does a hydrogen service station work?

Hydrogen is dispensed from a pump in the form of a gas. This means you can "fill up" in just a few minutes by connecting a nozzle to your vehicle's tank, just like a combustion engine vehicle.

However, because the hydrogen is in its gaseous state, the process used to convey it to the pump differs from that used at a petrol service station.

The hydrogen passes through various modules at the station before arriving at the dispenser: it is compressed for storage then cooled ready to be dispensed when a vehicle arrives at the pump. To find out how a hydrogen station works, click here.

How are hydrogen stations manufactured?

HRS hydrogen refueling stations are manufactured on an industrial scale.

This is possible thanks to HRS's technological expertise based on the integration of complex diverse expertise in high-pressure environments.

HRS stations are formed of at least four main modules:

  • Compression,
  • Storage (modular as required),
  • Cooling units,
  • Dispenser.

In addition to assembling the various modules, our teams design and assemble the piping required for the various components, as well as the electrical components, the automatic system, etc.

The stations are manufactured and assembled at our industrial site in Champagnier, part of the Grenoble urban area, with 10,000 m² dedicated to station production.

Can a hydrogen station be autonomous?

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.

To find out more about how a hydrogen station operates

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.

Does the HRS station produce hydrogen?

Our hydrogen refueling stations do not produce hydrogen, but are used to compress, store, and dispense hydrogen to vehicles for refueling.

HRS stations can be connected to all types of hydrogen source.

There are several methods for producing hydrogen and some refueling stations can be connected to an electrolyser installed on the site, which means the hydrogen is produced on site. This enables a continuous hydrogen supply, even in regions in which there is limited distribution of hydrogen.

Where are the hydrogen stations located?

The hydrogen pumps are accessible infrastructures, just like petrol and diesel service stations.

Currently in France and Europe, hydrogen vehicle fleets are mainly privately owned (companies, regional authorities, etc.), which means the stations are often located at private sites.

Companies have positioned themselves as hydrogen distributors and set up their own networks, as in France: Engie, Hympulsion, Hype, Sydev, Hygo

In 2022, there were 1070 stations listed throughout the world – a 55% increase compared to 2021 – the majority of which (> 650) were in Asia, 276 in Europe and 116 in America1.

HRS has positioned itself as a pure industrial player for H2 stations, with an annual production capacity of 180 stations, or one sixth of the world's installed base in 2022.

1 Hydrogen Council

Where can I find a hydrogen station in France? In Europe?

France Hydrogène has produced a map of H2 service stations in France, which is available from the Vig’Hy hydrogen observatory.

In Europe, hydrogen stations – both operational and under construction – can be found on the H2 live, H2 map and H2 stations websites.

Hydrogen stations are installed at public or private sites belonging to the owners of hydrogen vehicle fleets, therefore it is not yet possible to refuel with H2 at home as can be done with an electric vehicle.

According to France Hydrogène1, by 2030 there will be 1000 H2 stations across the country for refueling:

  • 300,000 light vehicles
  • 5000 heavy goods vehicles
  • 1000 boats
  • 250 trains

To view the stations installed by HRS: click here.

1 France Hydrogène

Can a hydrogen refueling point be installed at home?

Hydrogen refueling stations are equivalent to service stations used to "fill up" by connecting a nozzle to the vehicle.

It is not yet possible to install an H2 station at home like an electric recharging point, as this technology requires significant infrastructure comprising several modules.

The number of hydrogen refueling stations is gradually increasing across several countries, specifically in regions where the adoption of hydrogen as an energy source is encouraged.

Several applications hold information on hydrogen refueling stations throughout the world: H2 live, H2 map, H2 stations, Vig’Hy

What is the price of hydrogen at the pump?

The price of hydrogen is not calculated by the litre, but by the kg. €10-€20 per kg of hydrogen is the average price at the station, given that 1 kg is equivalent to a range of ~100 km for a passenger vehicle.

Several projects are under way to reduce the pump price, looking at both production and distribution.

Companies are undertaking large-scale projects to produce green hydrogen to be sold at a more competitive price. For example, Gaia Future Energy is aiming to produce 1 Mt of green hydrogen in Morocco by 2030 for the European market.

Reducing the pump price of hydrogen also requires a review of infrastructure costs. HRS has been able to scale up its stations activity by industrialising its hydrogen refueling station manufacturing process: thanks to a tripling of its production capacity following its move to the Champagnier site, HRS is aiming to boost the competitiveness of its products in order to promote access to H2 for mobility.

Work for Hydrogen Refueling Solutions

How do I apply to HRS?

To apply to HRS, please visit our website.

We are always looking for new talent to support our development, and we publish offers weekly in our job offers section.
Our offers include all necessary details, including the contract type, team, mission, required profile, and employment conditions.
You can then simply apply in a few minutes using the form provided for the relevant job offer. Once you have added your details and interests, simply upload your resume, and tell us why you want the job in the box provided so that the HR team can assess your application.

If you'd like to work for HRS but can't find a suitable position, you can send us a spontaneous application.

How can I check the progress of my application?

Once your application has been assessed, our Human Resources department will be in touch:

  • Either by phone, which means your profile is a match and we'd like to know more about you,
  • Or by email. We contact all applicants within three weeks of receiving their application to keep them updated on its progress.

After contacting you by phone, we'll arrange an interview with our HR team. Your HR contact will then keep you informed at each stage, based on the timetable you have agreed together.

Can I apply to HRS if I have no experience in hydrogen?

Depending on the position you're interested in, it may be possible to apply to HRS without a basic knowledge of hydrogen.

All employees undergo an integration programme on arrival, including:

  • A presentation explaining how a refueling station for hydrogen vehicles works, using our testing station
  • Raising awareness of hydrogen-related risks and safety issues
  • Scheduled meetings with all company departments

However, if a background in hydrogen is required, in particular for certain technical and scientific positions, this will be specified in the job offer.

Can I apply as part of a trainee or co-op programme?

Conscious that core professional competence is built largely on in-house training of young people and knowledge transfer, HRS has been taking on several trainees and co-op applicants per year since it was founded.

Numerous trainee and co-op positions are available every year. Go to our job offers section or send us a spontaneous application.

What professional training does HRS offer? What is the HRSchool?

HRS runs a wide-ranging employee training programme as part of its in-house training centre: HRSchool.

  • A training programme on short-staffed sectors
    This programme, created in partnership with the Isère training centre, UDIMEC and UIMM, offers tailored training based on a theoretical and technical programme delivered by professional trainers, as well as practical work supervised by internal tutors and an in-depth course on hydrogen.
    The aim is to train around 20 employees a year, with several staff members undergoing professional retraining.
  • An online training tool available to all.
    HRS offers its employees more than 5000 training courses on an interactive platform, enabling them to gain skills in languages, office automation, teamworking, management and more.
What training is available for working in the hydrogen sector?

The European Fuel Cell Hydrogen Observatory lists training courses leading to certification and qualifications in the hydrogen sector.

There are different types of hydrogen training in France: BTS, DUT, bachelor’s degrees, masters, for training technicians and engineers.

HRS recruits and trains its employees both on their arrival and throughout their career at the company, in order to develop their skills through knowledge sharing and cooperation.

What are the recruitment stages?

The length of the recruitment process may vary depending on the position and profile, but it always takes place in stages:

  1. You apply via the HRS website
  2. You receive a reply from the HR team
    • By phone for an initial conversation
    • By email within three weeks if your application has not been successful
  3. We invite you to HRS for an initial interview with our head of HR and the manager
  4. Depending on the type of position, we may give you a practical task to complete
  5. The HR team will contact you
  6. And if there's a match? You will receive a job offer
  7. You'll be welcomed into the #HRSteam: integration week, in-depth training on H2, welcome to the team!
What skills and professions are in demand in the hydrogen sector?

France Hydrogène surveyed over 80 key professions in the hydrogen sector, including technical and scientific competencies: mechanical engineering, process engineering, industrial electrical and computer engineering, fluid mechanics; and operational competencies: installation, assembly, mechanical, etc.

The surveyed professions encompass all fields (design, production, commissioning, operation, maintenance) and all training levels (secondary diploma, higher technical study at Bac+2 to Bac+5 and above) with or without basic knowledge of hydrogen.

As a manufacturer of hydrogen stations, the professions surveyed at HRS were in electrical and mechanical engineering, fluid mechanics, piping, metalwork, and support services: after-sales service, supply chain, business, finance, HR, communication, etc.

HRS advertises job offers in its engineering and R&D design office, its industrial production teams, and its support services.

Having identified short-staffed areas such as pipe fitting and cable fitting, in 2023 HRS launched its first in-house training centre dedicated to the hydrogen professions: the HRSchool.