What is the green hydrogen?

Green hydrogen is clean hydrogen produced from water using renewable electricity, enabling zero-emission energy for diverse sectors.

What are the benefits of green hydrogen?

It delivers low-carbon, flexible energy and helps decarbonize hard-to-abate industries, transport, and power.

What are the negatives of green hydrogen?

Current drawbacks include high production costs, significant infrastructure needs, and some energy losses compared to direct electrification.

Is green hydrogen the future?

Green hydrogen is set to play a major role in the global drive for net-zero emissions and sustainable energy.

What is green hydrogen and how is it produced?

Green hydrogen is hydrogen created by splitting water into hydrogen and oxygen using renewable electricity, typically with Proton Exchange Membrane (PEM) electrolysis or other electrolysis technologies, resulting in virtually zero CO₂ emissions.

Why is green hydrogen important for the energy transition?

Green hydrogen enables decarbonization of hard-to-abate sectors like chemical or steel industry, refining, shipping, and aviation, and makes renewable energy available beyond the power grid via sector coupling.

What are PEM electrolyzers and what makes them efficient?

PEM (Proton Exchange Membrane) electrolyzers use a membrane to separate hydrogen and oxygen gases while allowing protons to pass, harnessing volatile renewable energy with high efficiency, flexibility, and power density.

What scale of green hydrogen plants can Siemens Energy deliver?

Siemens Energy offers scalable solutions, from modular electrolyzer systems to 100 MW reference plants to gigawatt-scale installations, leveraging a prefabricated and modular electrolyzer core system for rapid deployment.

What sectors can benefit from using green hydrogen?

Green hydrogen can decarbonize power generation, chemical or steel industry, refining, shipping, and aviation, and buildings—especially sectors that cannot be directly electrified—by replacing fossil hydrogen or serving as feedstock for chemical synthesis, refineries or e-fuels and other derivatives.

Are Siemens Energy’s electrolyzer solutions suitable for volatile renewable sources like wind and solar?

Yes, PEM electrolyzers are especially suited for flexible, efficient operation with fluctuating energy inputs from renewables, maintaining high-quality gas output.

What service support does Siemens Energy offer for hydrogen plants?

Comprehensive service agreements are available, from basic maintenance to premium digital monitoring and long-term service agreements including extended warranties, plus full support along the hydrogen value chain.

How does Siemens Energy ensure reliability and safety at large-scale hydrogen plants?

Siemens Energy leverages decades of industry experience, learnings from several operational hydrogen projects as well projects in execution, advanced engineering, automation, and robust safety standards to deliver reliable, on-time, on-budget projects.

What is Power-to-X and how is Siemens Energy involved?

Power-to-X refers to converting renewable electricity into green hydrogen and its derivatives (like e-Methanol, e-Ammonia), supporting clean fuels for multiple sectors; Siemens Energy provides both technology and expertise for this transformation.

How can customers get started with a Siemens Energy green hydrogen project?

Contact Siemens Energy’s support team for 24/7 assistance, technical papers, and tailored project consulting to accelerate green hydrogen implementation from planning to operation.

Green Hydrogen Production I PEM Water Electrolysis

Electrolyzer for green hydrogen production

Green hydrogen (H₂) is a versatile energy carrier that can be applied to decarbonize a wide range of sectors. It can be used directly or in the form of its derivatives like e-Methanol, e-Ammonia, or e-Fuels to replace fossil fuels like coal or gas.

Only around 40% of global carbon dioxide (CO₂) emissions originate from power generation which can be decarbonized via electrification. The other 60% of CO₂ emissions originate from industry, mobility, buildings and others. These can be decarbonized via sector coupling, using green hydrogen and its derivatives to make renewable energy available to those sectors. This is why the production of sustainable hydrogen is so important for the energy transition.

New technical paper: Understanding electrolyzer aging and lifecycle

When discussing electrolyzer performance, the conversation often stops at the begin-of-life values. However, long-term safety, reliability, and lifetime behavior are equally critical – and even more complex. Knowing how these factors interact is crucial to plan power needs, maintain gas quality, and predict when maintenance or stack replacement is needed. Our new technical paper about electrolyzer aging and lifecycle is a comprehensive guide to metrics and best practices.

Cover of the technical paper "Understanding electrolyzer aging and lifecycle"

Generating green hydrogen efficiently from water and renewable energy requires high-end technology and innovative solutions — like our Elyzer product family from Siemens Energy. Using Proton Exchange Membrane (PEM) electrolysis, our electrolyzer is ideally suited for harnessing volatile energy generated from wind and solar.

Combining high efficiency and high power density, our PEM electrolyzers ensure gas products of superior quality. It is easy to operate and requires low maintenance. Using a modular design strategy that splits the electrolysis system into skids, we are able to optimize costs, reduce installation costs, and make the electrolysis system transportable.

Shows electrolyzer at Trailblazer project in Oberhausen

Carbon emission targets in the European Union and other industrialized countries will require massive scaling-up and acceleration of renewable hydrogen production and imports.

That’s why we have joined forces with Air Liquide to create a joint venture dedicated to the series production of industrial-scale renewable hydrogen electrolyzers. In 2023, we started production of electrolysis stacks at our multi-gigawatt electrolyzer facility in Berlin and will ramp up the production depending on market demand. The factory will supply stacks to Siemens Energy and Air Liquide for our broad range of customers and serve the rapidly growing market.

EU product rules for hydrogen electrolysis systems

Siemens Energy can offer comprehensive services for your electrolyzer plant and energy assets along the entire hydrogen value chain. The service agreements range from basic maintenance to premium service with state-of-the-art data analysis and can be customized to your needs.

A combined package of maintenance, support and digital services can ensure reliable and economical operation. You can reduce your risks with performance guarantees or enjoy total peace of mind with operations and maintenance service program. Together, we will push your clean hydrogen production to the next level.

Overview of Siemens Energy's services for the production of green hydrogen

Our Elyzer Coverage+ program is a long-term service agreement including extended warranties. It enables bankability of your renewable hydrogen project, keeping operational costs in check and ensuring plant safety and operability. Coverage+ leverages our experience in electrolyzer projects built on operational data, keeping energy consumption on track and assuring system reliability.

Learn more about our new service program:

PEM electrolyzer plant in Normand’Hy, France, to produce hydrogen for industry and mobility

Hamburg Green Hydrogen Hub (HGHH) Luxcara contract signing

54 MW PEM electrolyzer project at BASF’s Ludwigshafen site for hydrogen production and CO2 emission reduction in chemical industry

Our 20 MW electrolyzer project in Oberhausen with two people in front of stacks

Our 6 MW electrolyzer plant in Austria for the production of hydrogen for the steel industry

In PEM water electrolysis, water is split into its molecules, oxygen and hydrogen. This requires a PEM membrane as well as an anode and a cathode

Our Proton Exchange Membrane (PEM), simply explained, splits water into its molecules hydrogen and oxygen using an electric current. The PEM membrane serves as barrier between the two electrodes and allows the protons to pass through while preventing the mixing of the gases, facilitating the separation and collection of the hydrogen and oxygen gases.

PEM water electrolysis is an important technology for the production of hydrogen as a clean and sustainable source, as it provides a way to generate hydrogen gas using renewable electricity and water, without producing greenhouse gas emissions.

With our extensive knowledge of industrial, mobility, and energy sectors, we’re able to provide dependable solutions for our customers in every aspect of green hydrogen production.

You will benefit from Siemens Energy’s decades of experience, global footprint, infrastructure, strong partnerships and manpower available, covering the full energy value chain from renewable power via transmission to hydrogen and Power-to-X production. Moreover, we can help you certify the source of green energy with CertaLink certification.

Are you ready for the green hydrogen economy? We are and we look forward to being your partner for sustainable hydrogen generation.

Hybrid power solutions for decarbonizing independent energy supply and ensuring cost-effective, accessible power.

ESD focuses on cost-effective decarbonization for sustainable energy system transformation

Green hydrogen as a CO2-free energy carrier is essential for Power-to-X solutions and decarbonization efforts.

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Green hydrogen production

New technical paper: Understanding electrolyzer aging and lifecycle

PEM electrolyzer portfolio

Elyzer P-300 for large-scale sustainable hydrogen production

Scaling up the capacity of green hydrogen production

Experts insights: Technical papers on electrolysis

Your service partner for green hydrogen production and beyond

Elyzer® Coverage+ program

PEM electrolyzer systems in the field

EWE | Clean Hydrogen Coastline | Germany

Air Liquide Normand'Hy | France

Luxcara | Hamburg Green Hydrogen Hub | Germany

BASF | Hy4Chem-EI | Germany

Air Liquide Trailblazer | Germany

H2 Future | Austria

Understanding the process of PEM water electrolysis

Your partner for sustainable hydrogen production

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Get answers: FAQs on hydrogen solutions