Hydrogen Solutions

Your partner for sustainable hydrogen generation

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 and integrate them in developed industry, energy, and mobility infrastructures. 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

Decarbonisation / Hydrogen

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.

Use cases



About 90 percent of the more than 600 billion cubic meters of hydrogen produced annually worldwide is used by industry. Hydrogen is an essential chemical in industry that serves as fuel, additive, or reduction agent. Hydrogen is primarily used as a basic chemical in the synthesis of ammonia and other fertilizers such as urea, and for the synthesis of methanol, various polymers, and resins. Other major consumers in today’s hydrogen industry include refineries and the metalworking industry, as well as the semiconductor, glass, and food and beverage industries.



Only a small percentage of hydrogen is currently used in the energy sector, even though hydrogen is considered one of the most promising technologies in the large­scale integration of renewable energy. The more that electricity is generated from fluctuating renewable sources such as sun and wind and the less reliance there is on conventional power utilities, the more important it is that energy systems change. Ultimately, renewably generated power must also be available at times when sun and wind are scarce. This requires storing energy, including over extended periods of time. Hydrogen plays a key role as an energy source and storage medium. One example of a suitable infrastructure would be gas grids with their tremendous storage potential.

“Island solutions” can also be implemented using a hydrogen infrastructure. The highly dynamic behavior of a PEM electrolysis system is ideally suitable for direct connection to renewable power sources. Load peaks can thus be intercepted in the island grid and the energy can be fed back into gas turbines or fuel cells as needed.



The electrification of mobility is one of the greatest challenges in global decarbonization. Hydrogen can help to decarbonize this in two ways. Fuel cell vehicles can use hydrogen directly. Instead of CO2 and NOx, they pro­duce only water. Together with battery­powered vehicles, they not only reduce emissions from local urban traffic but also from interurban traffic and light and heavy­duty transport, because these vehicles have a significantly higher range than that of exclusively battery­powered vehicles – plus it takes only three minutes to refuel.

The second way hydrogen can help is through the synthesis of hydrocarbons from sustainable hydrogen and carbon from agriculture and forestry. In this way, even sectors with high fuel requirements, such as the aeronautics and shipping industries, can be decarbonized.

Electrolysis for sustainable hydrogen generation

As early as 1800, two Englishmen named William Nicholson and Anthony Carlisle discovered electrolysis, a process for splitting water into hydrogen and oxygen. Direct current was used. The two men thus founded a new field of chemistry, electrochemistry.

For many decades, the electrolysis of water was the standard method for producing hydrogen and led the French author Jules Verne, in his 1874 novel “The Mysterious Island” to state: “Water will be the coal of the future.” Over the years, gas reformation and coal gasification have prevailed as a major source of hydrogen, thanks to the development of the natural gas infrastructure.

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, PEM technology is ideally suited to harvesting energy generated from wind and solar power – which are irregularly generated – because it can be quickly switched on and off without any need for preheating. 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, 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.
SILYZER 300 – the next paradigm in PEM electrolysis

SILYZER 300 is the latest, most powerful product line in the double-digit megawatt range of Siemens’ 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.
SILYZER 200 – high-pressure efficiency in the megawatt range

SILYZER 200 can be adapted to your specific needs. Thanks to its design and practical expansion options, it offers maximum flexibility. The basic system consists of at least one 1.25 MW skid. Multiple basic systems can be combined into a PEM electrolysis network in a higher performance class. Depending on your needs, a variety of technical options round out the complete package, including a recooling system, water treatment system, power grid connection, and much more. And, of course, all components are perfectly compatible. It even handles hydrogen production when operated under high pressure of up to 35 bar.


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 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’ 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’ proven quality – including our SIMATIC PCS 7 control system and converters in the SINAMICS DCM series. 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.

Further information

Information for our customers


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.

Production, storage, transport

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.

Energy transition

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.


Our systems in the field