Hydrogen Solutions

Your partner for sustainable hydrogen generation

The power of Hydrogen

One of the most important challenges today is the decarbonization of the global economy. The key to meeting this challenge is to consistently expand renewable energy sources as well as the concept of sector coupling, meaning to integrate renewables in developed industry, energy, and mobility infrastructures with Power-to-X solutions using green hydrogen. We generate “green” hydrogen from renewable energy using PEM electrolysis, and in doing so make an important contribution to the global energy transition. The Silyzer product line helps you integrate fluctuating energy sources such as sun and wind in your process. We are setting the standards when it comes to sustainable hydrogen generation for the future. From planning and commissioning to operation, we support you as a reliable partner with a proven service concept tailored to your requirements.

Hydrogen – fuel of the future

Renewable energy is playing an increasingly important role worldwide. It’s the backbone of a sustainable, CO2­ free energy sector, and thus a key technology for achieving decarbonization by the year 2100. Its share in global power generation is growing daily. But how can fluctuating energy sources such as sun and wind be integrated in existing grids, ongoing industrial processes, and flexible, individual mobility?

Hydrogen isn’t just the fuel of the future – it’s the fuel of the present!

Hydrogen is the most common element in the universe. Almost all of our chemical fuels are based on hydrogen, although in a bound form as hydrocarbons or other hydrogen compounds. To limit climate change caused by the global increase in CO2 emissions, solutions must be found for generating carbon­neutral and, therefore, sustainable fuels. This requires, among other things, that hydrogen is produced using renewable energy sources.

Joint venture for the production of large-scale hydrogen electrolyzers

Siemens Energy and Air Liquide announce the creation of a joint venture dedicated to the series production of industrial scale renewable hydrogen electrolyzers in Europe. With two of the global leading companies in their field combining their expertise, this Franco-German partnership will enable the emergence of a sustainable hydrogen economy in Europe and foster a European ecosystem for electrolysis and hydrogen technology. The joint venture multi-gigawatt factory will supply stacks to both Groups for their respective broad range of customers and to serve the rapidly growing market.


What is Power-to-X?

Power-to-X describes methods for converting electrical energy into liquid or gaseous chemical energy sources through electrolysis and further synthesis processes. Using electrical current, water is split into oxygen and hydrogen – a 100% CO₂ emission-free process. Being a key technology for the energy transition, Hydrogen can be easily stored and further used or processed in many ways. 

Sector coupling via power-to-X has the potential to reduce primary fossil energy consumption by 50% even while power demand grows by 25%

  1. Mobility: Power-to-X produces synthetic fuels for immediate application: e-Methane, e-Methanol, e-Diesel, e-Gasoline or e-Jet fuel – ready for instant use. They can be blended gradually with fossil fuels until they fully replace fossil fuels as a primary energy source. 
    Existing infrastructure such as gas pipelines, gas stations, or storage facilities can be used as well as existing and low-cost consumer applications, powered by e-Fuels.
  2. Power generation: Modern gas turbines can be operated with a mix of hydrogen and natural gas, with a hydrogen share of 5 to 100%. Hydrogen can be cached, transported in gas grids and re-electrified in gas turbines, combined cycles or fuel cell power plants.
  3. Industry: Large heat demand; H2 enables CO2-free metal production; Green hydrogen as feedstock for production of ammonia and other products.  

White papers

Good to know

Benefit from our know-how by the download of technical papers from Siemens Energy.

Electrolyzer manufacturing

We expect the hydrogen market to grow significantly in the coming years. In this video get an impression of our factory and see how we are preparing for this demand by working on a flexible ramp-up.

PEM-Electrolysis – dynamic, efficient, clean

J. H. Russell and his colleagues first recognized the enormous potential of PEM electrolysis for the energy industry in 1973.

PEM takes its name from the proton exchange membrane. PEM’s special property is that it is permeable to protons but not to gases such as hydrogen or oxygen. As a result, in an electrolytic process the membrane takes on, among other things, the function of a separator that prevents the product gases from mixing.


On the front and back of the membrane are electrodes that are connected to the positive and negative poles of the voltage source. This is where water molecules are split. In contrast to traditional alkaline electrolysis, the highly dynamic PEM technology is ideally suited to harvest volatile energy generated from wind and solar power. PEM electrolysis also has the following characteristics:

  • High efficiency at high power density
  • High product gas quality, even at partial load 
  • Low maintenance and reliable operation
  • No chemicals or impurities

Our Silyzer portfolio: the optimized solution for your requirements

Generating sufficient amounts of hydrogen requires innovative solutions – like the Silyzer product family from Siemens Energy, an innovative PEM electrolysis system that uses wind and solar energy to produce hydrogen and is totally CO2-free. That makes Silyzer twice as useful – and twice as clean.

The next paradigm in PEM electrolysis

Silyzer 300 is the latest, most powerful product line in the double-digit megawatt range of Siemens Energy’s PEM electrolysis portfolio. Silyzer 300’s modular design makes unique use of scaling effects to minimize investment costs for large-scale industrial electrolysis plants. The optimized solution results in very low hydrogen production costs thanks to high plant efficiency and availability.


Decarbonize your industry with a system that

  • offers the highest level of efficiency and extraordinary dynamics at a competitive price and with low maintenance requirements,
  • is free of hazardous substances,
  • delivers nothing but pure hydrogen of the highest quality.

We put together the perfect package for your individual needs. Our services range from basic maintenance activities to comprehensive all-round service using state-of-the-art data analysis. In this way, we guarantee smooth operation.

Our service offerings are tailored to individual customer requirements:

  • Basic: Support and troubleshooting on demand
  • Advanced: Preventive maintenance, remote service, condition monitoring, 24/7 hotline, and more
  • Integrated: Performance based maintenance contracting
Siemens Energy as partner

170 years’ experience and ingenuity

Your partner – competent, reliable, experienced. 

For over 170 years, we and our products have been meeting the highest quality standards. With our extensive knowledge of the industry, mobility, and energy sectors, we’re able to develop cross-industry solutions that are designed to generate added value for our customers. From grid integration to innovative control technology, you benefit from Siemens Energy’s decades of experience and innovative strength. We also have access to an extensive network of select partners who optimally complement our offerings. This knowledge and experience enables us to create tailored solutions based on individual customer requirements, and thus exploit the full potential.

Silyzer is loaded with high technology and expertise – naturally, in Siemens Energy’s proven quality. We ensure that all the components work together reliably and optimally while guaranteeing maximum availability, reliability, and safety. You can be sure that we’ve combined all our experience and expertise in a high-quality system and are available to you around the clock as a dependable partner.


Our System in the field

FAQ – The most common questions on hydrogen

Hydrogen (chemical symbol H) is a gas. As a molecule (H2), it occurs only in small amounts in nature and it is mainly chemically bound, such as H2O.

Hydrogen is the most abundant element in the universe. 90 percent of all atoms are hydrogen atoms. They add up to three quarters of the total mass in the universe.

Hydrogen converts into a liquid at minus 253 ºC.

Hydrogen has the highest energy density of all conventional fuels by mass: almost three times as high as that of gasoline or diesel. That is one of the reasons why hydrogen is used as fuel for space travel.


H2 Higher  Heating  Value: 39.4 kWh/kg; H2 Lower Heating  Value: 33.3 kWh/kg

By combusting hydrogen, it delivers heat. Used in fuel cells, hydrogen is converted electrochemically  to electrical energy.

Hydrogen has been produced and used for more than 200 years. Experience shows that hydrogen can be stored, distributed and converted safely. As early as 1808, the first large-scale use of hydrogen was established for the street lighting system in London.

Hydrogen (H2) can be produced in different ways. For the moment more than 95% of the hydrogen worldwide is produced from hydrocarbons while producing and emitting harmful CO2. A more modern and ecofriendly technology for CO2 neutral production of hydrogen can be offered by electrolysis of water.

Hydrogen can be produced from hydrocarbons by steam reforming of natural gas - often referred to as steam methane reforming (SMR), coal gasification and from an electrolysis process of water (H2O).

Hydrogen can be stored in tanks as a compressed gas or as a liquid. Hydrogen can also be stored in caverns or in the natural gas grid for different applications and if the grid fulfils all technological requirements.

The volumetric energy density of hydrogen at atmospheric pressure is approximately one third of traditional fuels. The volumetric energy density can be increased by compression or liquefaction of the hydrogen gas to store and transport a greater amount of hydrogen.

For hydrogen-powered vehicles, an industry standard of 300 to 700 bar has been established. Vehicles for the transport of compressed hydrogen, so called “tankers”, usually working with a maximum pressure of 200 bar.

Hydrogen can be transported as a compressed gas or a cryogenic liquid. Today, the two main methods for transporting hydrogen (primarily in a gaseous state) are via tanker e.g. tube trailer for road transportation and in gas pipelines (for short distance).

Hydrogen is a non-toxic clear gas. It is not poisonous, has no taste or odor. Using hydrogen as a fuel source with fuel cells does not create fumes, pollute the atmosphere with carbon dioxide or emit nitrogen oxides.

It is not inherently more dangerous than other fuel sources.  Hydrogen is flammable and must be handled with care, just like other flammable fuels. To ignite, the hydrogen must be combined with an additional oxidizing agent (air, pure oxygen, chlorine, etc.) in a specific  concentration and an ignition source (a spark). If, in a worst-case scenario, the hydrogen ignites, it burns upwards very quickly. It creates no dangerous heat radiation above the accident site, as petrol or kerosene do.

The facilities are designed to be permanently leak proof. Flange connections are designed especially for hydrogen and the number of detachable connections are minimized. Furthermore, in buildings a steady air exchange is ensured and the facilities are equipped with safety valves and pressure reliefs. Additionally explosion prevention zones are designated. In these zones, electrical and other equipment needs to be in accordance with 2014/34/EU (ATEX Directive).

No. Hydrogen can be safely handled and stored as well as transported. The industrial gas industry has done so for over a century.

In contrast to gasoline and natural gas, hydrogen gas has significant buoyancy in atmospheric conditions due to its low density, any leaking hydrogen gas ascends immediately and disperses, which reduces the risk of an ignition in open air.

Water gets split into its components hydrogen and oxygen by means of electrical current.

Electrolysis processes can be categorized as follows: alkaline electrolysis with liquid alkaline electrolytes, acidic electrolysis with a solid polymer electrolyte (as PEM) and high temperature electrolysis with a solid oxide as electrolyte.    


PEM electrolysis and alkaline electrolysis systems are available at an industrial scale. The solid oxide electrolysis technology is in an early development phase.

PEM is the abbreviation for proton exchange membrane. This membrane is a crucial part of the electrolytic cell in a PEM-electrolyzer. The membrane separates the anode, where the oxygen is collected, and the cathode, where the hydrogen gas is generated.

The type of the ions which closes the electric circuit


  • PEM: H+
  • Alkali: OH-
  • SOE: O2-
  • High gas purity >99,999%
  • High dynamics
  • High efficiency (>70%)
  • High power density
  • High life cycle
  • Clean (no chemicals, only water and electricity)

10 liter demineralized water is needed for 1kg of hydrogen.

On average 50kWh are necessary to produce 1kg of hydrogen, depending on the efficiency of the electrolyzer and operation mode.

The hydrogen market is divided in three sectors. Mobility, energy and industry with industry being by far the largest consumer today (~90%). In the future a redistribution towards the mobility and energy sector is expected .

Today, hydrogen is an important industrial gas, i.e. for the refining of fuels, for the production of fertilizer and methanol, for the hydrogenation of fats, for steel production, metal processing, as well as in the production of flat glass.

Less than 1kg of hydrogen is needed per 100km.

Passenger car or light duty vehicle fueling takes 3 to 5 minutes.

Hydrogen enables the long-term storage of large quantities of surplus renewable energy. It is allows new ways to use green electricity, i.e. by using hydrogen as substitute for natural gas by feeding it into existing pipelines, as fuel for fuel-cell vehicles or power plants, or as feedstock for the hydrogen processing industry. It opens the possibility to connect energy generation with the industry and mobility sectors, the so called “sector coupling”.

No. Hydrogen will become a substantial and permanent element of a sustainable energy industry.

In the future, hydrogen will be produced to a greater extent using electricity from renewable energy sources. Furthermore, biogas and various fuels like solid biomass will help to produce green hydrogen in the future.

‘Green’ hydrogen is sourced by 100% renewable energy. That means that the needed energy to produce hydrogen by electrolysis has emitted zero emissions. Hydrogen produced from fossil fuels releasing emissions such as CO2, may be referred to as ‘grey’ or ‘brown’ hydrogen. If the emitted carbon dioxide is captured, stored (carbon capture storage) and re-used, it is often called ‘blue’ hydrogen.


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