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Transforming Aviation: Siemens’ Hydrogen Revolution

Welcome to another insightful episode on, where we explore the fascinating world of renewable energy and its groundbreaking advancements. Today, we’re delving into a topic that’s not only innovative but also a significant leap towards a sustainable future: Green Hydrogen in Aviation. Specifically, we’ll be focusing on Siemens’ pioneering research and development in hydrogen-powered jet engines. This technology promises to revolutionize the aviation industry by harnessing the power of green hydrogen, offering an environmentally friendly alternative to traditional fossil fuels. Join us as we unravel the complexities, challenges, and potential of this cutting-edge technology, paving the way for a cleaner, greener tomorrow. Stay tuned as we embark on this exciting journey into the future of aviation!

Overview of Green Hydrogen in Aviation

Significance and potential of hydrogen in sustainable aviation.

The significance and potential of green hydrogen in sustainable aviation are immense, marking a pivotal shift towards a cleaner, more sustainable future in air travel:

  1. Essential for Net-Zero Climate Strategies: Green hydrogen, produced entirely from renewable energy, is gaining momentum globally as a zero-emission energy carrier. It’s an essential component of net-zero climate strategies, especially for hard-to-abate sectors like aviation. Governments worldwide are increasingly focusing on green hydrogen to meet ambitious climate-neutrality targets.

  2. Rapid Growth in Green Hydrogen Production: Currently, green hydrogen accounts for less than 1% of total hydrogen production. However, with falling renewable energy costs and booming investments in electrolyzers, its production capacity is expected to increase significantly. Some estimates suggest a 50-fold increase in the next six years, potentially meeting up to 25% of the world’s energy needs by 2050. This scale-up is critical for meeting the Paris Agreement’s 1.5-degree Celsius target.

  3. Global Expansion and Cost Reduction: The International Energy Agency (IEA) has recorded nearly 320 new green hydrogen production projects worldwide, indicating a significant expansion in electrolyser capacity. In Europe, ambitious plans aim to install at least 40 GW of electrolyser capacity by 2030, which would make it the world’s largest green hydrogen producer. Similarly, countries like Australia, Japan, South Korea, China, and the USA are rapidly developing their green hydrogen infrastructure. The shift from megawatt- to gigawatt-scale projects is expected to drive down costs through economies of scale, making green hydrogen more cost-competitive.

  4. Implications for the Aviation Industry: Companies like Airbus expect green hydrogen to power their future zero-emission aircraft, aiming for market entry by 2035. The challenge lies in scaling up green hydrogen production to meet the aviation industry’s needs. The sector’s commitment to decarbonization, coupled with the advancements in green hydrogen production, sets a promising path for the future of sustainable aviation.

Siemens’ Vision in Hydrogen-Powered Aircraft

Siemens’ approach to hydrogen-powered aviation and their objectives.

Siemens’ vision for hydrogen-powered aircraft is a cornerstone in the pursuit of sustainable aviation, reflecting a commitment to innovation and environmental responsibility. Their approach and objectives in this realm can be summarized as follows:

  1. Advocating for Carbon-Neutral Propulsion: Recognizing the increasing intensity of climate change, Siemens is at the forefront of exploring new carbon-neutral propulsion methods, with a particular focus on hydrogen. Due to its high energy density, hydrogen is seen as especially suitable for large-scale and commercial aviation. This shift requires significant changes in aircraft design, including new storage systems and ground infrastructure. Digitalization, including virtual testing and integration capabilities, plays a crucial role in developing functioning hydrogen-powered aircraft.

  2. Hydrogen’s Advantages Over Other Fuels: Hydrogen stands out for its multiple advantages over other sustainable propulsion systems, like electric batteries and synthetic fuels. Its energy density is nearly three times that of kerosene, and its main byproduct is environmentally friendly water, offering a high energy output with no carbon footprint. Different methods to harness hydrogen for aviation are being explored, including hydrogen-powered gas turbines, hydrogen fuel cells, and hybrid systems combining both. These diverse applications provide engineers with ample opportunities to explore various aircraft designs.

  3. Overcoming Design Challenges: The transition to hydrogen necessitates overcoming several design challenges. Hydrogen burns hotter and faster than kerosene and is highly flammable, necessitating additional safety measures in turbines and storage tanks. Also, hydrogen takes up more volume than kerosene, which impacts storage solutions, whether as a gas requiring pressurized tanks or as a liquid needing cryogenic temperatures. These storage requirements have significant implications for the rest of the aircraft’s design, potentially leading to alternative configurations like blended wing aircraft.

  4. Utilizing Digital Twin Technology: To address the challenges in designing hydrogen-powered aircraft, Siemens employs digital twin technology through its Simcenter software. This technology allows for the creation of virtual aircraft models, enabling engineers to test and optimize design choices efficiently. The integration of different design domains such as thermal and mechanical systems is facilitated through digitalization, helping engineers develop safe and sustainable hydrogen-powered aircraft that align with sustainability goals.

  5. Reimagining Aircraft Configurations: Siemens’ research into hydrogen-powered jet engines and hydrogen fuel cell technology is integral to driving next-generation propulsion systems. This endeavor involves reimagining aircraft configurations and addressing multiple aspects like materials, supply chains, energy production, distribution, and logistics networks. Ensuring compatibility with existing airport fuel delivery systems is also a crucial part of this transformation.

  6. Addressing Engineering Challenges: The nature of hydrogen presents unique engineering challenges, such as designing burners for hydrogen gas turbines and managing the stresses at thermal boundary conditions. Understanding the fluid dynamics and operational phenomena like flashbacks, thermoacoustics, and thermal gradients is essential for the safe operation of hydrogen and electric-powered propulsion systems.

  7. Optimizing Aircraft Performance: Siemens’ Simcenter software, a part of the Siemens Xcelerator portfolio, is instrumental in optimizing aircraft performance through virtual and physical testing. It enables the evaluation of various components like engine architecture, gas turbines, fuel storage, fuel cells, and batteries, which are crucial for the development of hydrogen-powered aircraft.

Design Challenges and Innovations

The engineering challenges faced and innovations made in designing hydrogen-powered aircraft

Designing hydrogen-powered aircraft involves overcoming several significant engineering challenges, but recent innovations are also highlighting the immense potential of this technology:

Engineering Challenges

  1. Hydrogen Storage: One of the major hurdles is the storage of liquid hydrogen, which has a volumetric density four times less than jet fuel. This means it requires significantly more space, posing a challenge for onboard storage. Cryogenic cylinders, necessary to store hydrogen at extremely low temperatures, demand specialized materials, thicker walls, and isolation features, adding complexity to the design.

  2. Structural Weight and Storage Location: The high volume of hydrogen impacts the aircraft’s structural weight. Unlike jet fuel, which can be stored in wing tanks, hydrogen cylinders are too large for this and require alternative storage solutions. This has led to designs that place hydrogen tanks in the fuselage or on the outer wings, altering the traditional aircraft configuration.

  3. Transport and Refueling Challenges: The handling of hydrogen in its liquid state, which requires maintaining extremely low temperatures, adds complexity to transport and refueling processes. Controlling temperature is critical to prevent leakage and vaporization, which can occur during storage and refueling.

  4. Combustion Behavior: Hydrogen burns faster than natural gas, necessitating controlled combustion processes. This requires precise management of its high burning velocity and broader flammability range, which poses a significant engineering challenge​​.

  5. Infrastructure and Supply Chain: Developing the infrastructure to support hydrogen-powered aircraft is complex. Safe and economical transportation of volatile liquid hydrogen, along with stringent safety regulations for handling, storing, and refueling, necessitates a comprehensive overhaul of current airport infrastructure.


  1. Diverse Utilization Methods: Hydrogen offers multiple methods for powering aircraft, such as hydrogen-powered gas turbines, hydrogen fuel cells, and hybrid systems. These diverse applications open up various avenues for aircraft design, allowing for flexibility and innovation in utilizing hydrogen for aviation.

  2. Liquid Hydrogen Advantages: Compared to gaseous hydrogen, liquified hydrogen enables lower tank weights and volumes, significantly increasing aircraft range and payload. This has been demonstrated in recent test flights, where the use of liquid hydrogen doubled the maximum range of an aircraft.

  3. Commercial Viability Demonstrations: The successful completion of the world’s first piloted flight of an electric aircraft powered by liquid hydrogen marked a significant milestone. This achievement demonstrates the feasibility of using liquid, cryogenic hydrogen in aircraft, paving the way for medium and long-range emissions-free flight.

  4. Digitalization in Design: The integration of digital technologies like the digital twin is crucial in addressing the challenges of designing hydrogen-powered aircraft. This allows for virtual testing and optimization of design choices, reducing the need for physical prototypes and enhancing the efficiency of the design process.

  5. Applications Beyond Aviation: The successful use of liquid hydrogen in other vehicles, like commercial trucks, highlights its broader applicability and potential in transportation. This further validates the feasibility of hydrogen as a sustainable fuel source in various sectors.

Simcenter Software and Digital Twin Technology

Role of Simcenter software in optimizing aircraft performance and design.

Siemens’ Simcenter software, utilizing digital twin technology, plays a pivotal role in optimizing aircraft performance and design, especially in the context of green aviation and the use of alternative energy sources such as hydrogen. This technology is instrumental in addressing the unique challenges and requirements of next-generation aircraft designs. Here are the key aspects of how Simcenter and digital twin technology are utilized:

  1. Optimizing Aircraft Performance: Simcenter software supports the development of hydrogen-powered aircraft by providing capabilities for virtual and physical testing across various system domains, including fluid, thermal, and mechanical. This enables aerospace engineering organizations to optimize aircraft performance, contributing significantly to the advancement of green aviation.

  2. Revolutionizing Aircraft Configurations: The shift to alternative power sources like hydrogen necessitates new aircraft configurations. Digitalization and the use of digital twins are crucial in addressing these challenges. Engineers benefit from virtual prototypes that enable them to run simulations before building and deploying physical prototypes. This approach is key in creating successful next-generation aircraft and propulsion systems.

  3. Integrated Design Environment: The Siemens Xcelerator portfolio, which includes Simcenter, provides an integrated design environment for multi-disciplinary aerospace engineering teams. This environment is essential for modeling, analyzing, and testing the impact of alternative energy sources and propulsion systems on future aircraft configurations. Simcenter supports sustainable aviation by providing proof of compliance data through both virtual and physical testing, which is critical for the mission-critical certification process.

  4. Design Space Exploration and Simulation Synthesis: Siemens employs an innovative approach for design space exploration for aircraft mechanical systems using Simcenter solutions. This approach involves architecture generation and simulation synthesis, enabling engineers to automatically synthesize simulation models and generate simulation workflows based on requested outputs. This methodology streamlines the design process, automates many repetitive and non-creative tasks, and increases the reuse of knowledge and models.

  5. Support for Optimal Integration: For distributed propulsion systems, Simcenter supports engineering decisions for optimal aerodynamic, electrical, thermal, and structural integration. This is crucial in designing aircraft that efficiently utilize alternative energy sources, ensuring that the aircraft meets both performance and sustainability goals.

The Zero Emission Hydrogen Turbine Center (ZEHTC)

The Zero Emission Hydrogen Turbine Center (ZEHTC), spearheaded by Siemens, is a pioneering project in the field of sustainable energy systems. Here are key insights into the ZEHTC project and its contributions to hydrogen research:

  1. Project Overview: The ZEHTC is a transformative initiative that aims to move the world away from fossil fuels. Siemens expanded its gas turbine test facility in Finspång, Sweden, for this purpose. The project involves international partners and has established a demonstration plant showcasing a sustainable energy system that integrates gas turbines with hydrogen, renewable energy, and energy storage.

  2. Closed Loop Plant and Research Focus: The ZEHTC operates as a closed-loop plant, utilizing excess energy from gas turbine tests and solar panels to produce hydrogen through an electrolyzer. This setup not only supports ongoing research and development to optimize hydrogen use in gas turbines but also aligns with Siemens’ goal of running gas turbines on 100% hydrogen by 2030.

  3. Supporting a Sustainable Energy System: The center focuses on gaining more knowledge about microgrids and energy storage, which are vital components of a sustainable energy system. Moreover, it has extended hydrogen testing resources, enhancing the hydrogen capability of Siemens’ gas turbines.

  4. Collaborative Effort: The project is supported by funding from ERA-Net SES and the Swedish Energy Agency (2019-2022). It is a consortium involving six partners from both private and public sectors, including two international universities, reflecting a collaborative approach to tackling the challenges of sustainable energy.

Future Prospects and Environmental Impact

The future prospects of hydrogen in aviation and its environmental impact are significant:

Zero Emissions and Reduced Air Pollutants: Hydrogen-powered aircraft produce zero CO2 emissions and, depending on the technology, can substantially reduce or eliminate air pollutants like nitrogen oxide, also helping to prevent contrail formation.

Growing Momentum in Europe: The interest in hydrogen technology in aviation has surged, especially after Airbus’ announcement in 2020 about zero-emission commercial aircraft based on hydrogen potentially entering service by 2035. Creating a hydrogen infrastructure, however, is crucial for this development.

Development of ‘Hydrogen Hubs’: Initial steps have been taken towards this future, with Group ADP collaborating with Air France-KLM and the Paris Region to transform Parisian airports into hydrogen hubs. Reducing Climate Impact: Hydrogen propulsion can lead to a 30-50% reduction in impacts from contrail and cirrus formation compared to kerosene aircraft. The climate impact in flight could be reduced by 50-75% with hydrogen combustion, and by 75-90% with fuel-cell technology.


The ZEHTC project by Siemens represents a significant step towards integrating hydrogen into the energy system, particularly in the aviation sector. With its focus on sustainable energy solutions and collaborative research, the center is helping to pave the way for a decarbonized future. The broader environmental impact of hydrogen in aviation is profound, offering a path to zero emissions and significantly reduced air pollutants. The future of aviation, steered towards sustainability by projects like the ZEHTC and the growing interest in hydrogen technology, looks promising. This transition not only aligns with global climate goals but also sets a new standard for innovation in the aviation industry.

Here is a comprehensive list of all the references used throughout the article:

Hydrogen Airplane | Green Aviation – Siemens. Available at:

Zero Emission Hydrogen Turbine Center (ZEHTC) – Siemens Energy. Available at:

The green hydrogen ecosystem for aviation, explained | Airbus. Available at:

What Are The Major Challenges Of Hydrogen-Powered Aircraft? – Simple Flying. Available at:

Hydrogen-powered aircraft design & digitalization | Siemens Thought Leadership. Available at:

World’s First Crewed Liquid Hydrogen-Powered Plane Takes Off – TOMORROW’S WORLD TODAY®. Available at:

Are hydrogen-powered aircraft the future of sustainable aviation? | EUROCONTROL. Available at:

Design space exploration for aircraft systems with Simcenter – Simcenter. Available at:

Green Aircraft | Digital Twin Aerospace | Siemens. Available at:

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