With Power-to-X, Siemens Energy is powering the world sustainably
In the sustainably energised society of the near future, green hydrogen makes it possible to meet growing global energy demand while combating climate change

The future of the planet depends on humanity's next steps. Photos: Shutterstock
An energy transition is underway – and it has the potential to achieve decarbonisation on a greater scale than ever before. This year alone, the climate crisis has caused severe heatwaves in the Pacific Northwest, set record temperatures in Antarctica and stoked fears about flood dangers for millions in Southeast Asia.
The need to minimise carbon emissions and reliance on fossil fuels has never been more urgent.
While fossil fuels remain dominant for now in the energy sector, Mr Brian Byrne, senior vice president of Siemens Energy Asia Pacific Hub, shared that forthcoming advancements in clean energy solutions and renewables will lower the cost of adoption and make these solutions far more viable options. “There is a need for us to adopt a holistic approach – combining a multitude of innovative technologies and fostering ecosystem partnerships with public and private key stakeholders. In particular, governments play a significant role through their support, which will enable technology innovation and accelerate adoption. Bundling our strengths and learning from each other will bring critical value while building the momentum on this transformation pathway.”
At the same time, energy needs are rising across the globe as economies continue to grow. Global demand for energy is predicted to increase by around 25 per cent through 2040 – and will be matched by a rise in the level of climate-damaging greenhouse gases.
Innovative emerging technologies can bridge the sustainability gap and drive decarbonisation even among energy-heavy industries that have not yet benefited from existing climate-friendly solutions.
“Digitalisation and adaptation to these new technologies will be key in breaking down silos between energy demand and supply, and stimulate the integration across different sectors. Energy systems and power-intensive industries around the world will need to keep up with these trends and capitalise on new opportunities. This will allow us to shift towards a decarbonised society and advance the global agenda of Sustainable Development Goals (SDG),” explained Mr Byrne.
COUPLING SECTORS, THROUGH POWER-TO-X
Though much of the focus thus far has been on decarbonising the electricity sector, Mr Byrne pointed out that the energy sector only accounts for about 40 per cent of total carbon emissions compared to usage-heavy sectors like mobility, building, industry and heating, which produce the bulk of emissions.
Sector coupling can support decarbonisation efforts in these sectors. He said: “Focusing on the energy sector is not sufficient. Closing the loop of the energy production as well as integrating and adopting the usage to all other sectors should be the focus now. This is where the combination of Sector Coupling and Power-to-X methodology will play an important role in closing the CO2 cycle.”
While sector coupling has the potential to reduce primary fossil energy consumption by 50 per cent, it requires complex structures with the need for optimised operation and control modes. Power-to-X processes – which convert electrical energy to liquid or gaseous chemical energy sources – are the key to creating closed CO2 cycles and CO2 neutral infrastructures, when combined with sector coupling.
Power-to-X allows for energy-dense synthetic fuels (e-fuels) to be generated from renewable electrical energy, in order to replace fossil fuels. The renewable electrical energy sources could be drawn from the excess electricity produced by wind or solar farms, which currently are reduced in activity or temporarily shut down when they produce too much power for the electrical grid.
These e-fuels – such as e-methanol, e-methane, e-jet fuel and e-diesel – are sustainable, carbon-neutral and can be easily stored. They can also be mixed with conventional fuels to reduce the latter’s carbon content over time, without the need to change existing vehicle or fuel logistics infrastructure. This is especially useful for long-haul heavy transportation, marine and aviation sectors for which the potential of electromobility is limited or non-existent.
DRIVEN BY GREEN HYDROGEN
Every year, 70 to 80 million tonnes of hydrogen are produced globally, usually by steam methane reforming or autothermal reforming. How hydrogen is produced determines how climate-friendly the resulting product is. Each type is labelled by colour: The least sustainable, grey hydrogen, is produced using fossil fuels, while blue hydrogen is produced through steam methane reforming of natural gas. The cleanest option, green hydrogen, comes from water electrolysis that is powered in turn by renewable energy such as solar and wind.
As a resource, hydrogen has many applications, including hydrocarbon cracking in refineries, fat hardening in food production, and as a component in ammonia phosphate and urea. It can also be easily stored and used as direct fuel for mobility, as feedstock for various industries or converted into e-fuels.
When sustainably produced, hydrogen has the power to play a significant role in the future of energy. It can drive the decarbonising of fossil-fuel reliant sectors such as industry, transport and the built environment – which combined, produce more than half of global carbon emissions. For example, energy-efficient hydrogen fuel cells are set to replace diesel engines for trains and can also be used as a sustainable option instead of electric-vehicle batteries in cars and heavy vehicles, thus avoiding limitations such as longer charge times and maximum mobility ranges.
As more sectors explore sustainable and clean alternatives to fossil fuels, the demand for green hydrogen is expected to increase in the coming years. At Siemens Energy, the Power-to-X process to produce green hydrogen consists of water electrolysis, using renewable electrical energy. Using a proton exchange membrane (PEM) electrolysis system, Siemens Energy’s Silyzer portfolio is a powerful solution for renewable hydrogen production – completely CO2-free. In addition to producing high-quality and constant green hydrogen over its operating life, innovative advances have informed Siemens Energy’s Silyzer 300’s modular design, which allows for scaling effects to minimise investment costs for large-scale industrial electrolysis plants.
In combination with other energy-efficient technologies like heat pumps, electromobility and combined heat and power plants, Power-to-X is essential for reducing carbon emissions – and for building a sustainably energised society. Power-to-X enables a smooth, gradual transition from the fossil world to a carbon-free one by steadily increasing the sustainable content in fuels and making green hydrogen a cost-effective option.
Said Mr Byrne: “At Siemens Energy, we believe that sustainably produced hydrogen is a key technology for the energy revolution. The challenge now is to scale up the production and bring green hydrogen to other sectors to electrify the entire ecosystem, and finally bring the overall cost down. With a strong and resilient portfolio along significant parts of the energy value chain, we are well-positioned to lead the way to support the decarbonisation of the entire energy system and support our customers in their various transition phases.”
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